TN295 No. 8937 -;; v-^^ o^.i^j^%'^°o .•^*\t^.t.^^ c^.*^:^.% .•^*' .i^^'.V /.c:;^^ °o V v^irfaw* ^ -ftp • '?', '^^,>^ '♦bv^ '^bv* _. /•4i^^\** /*>;^'"°- //^iX ^°*>i^'> .'^^•^iX ^°^>^'- V *^-' y %. '-Too ^0 ^^ ' 5' '^ai^. <^^^^^'^ *. CV V _ jPvt, .0^.. «40t. . V *-^.* .^^' "q, -T^o- ^o' --^^^ -^ .O"^ .'V- V V^^**./"" V'^^*'/' ^V^"'\^^ a5°^ «' ^^-n.^, ■•y^ %--^%o' -*^/^.- .*^ V-^^-.o' *^-^'\/ V-^-.o'' s* •.^^'•. V.<«>* .>>Wa- ** A* •'^^•- ■%. 0.** .>Va- *,. > .-(isfi&i-. V ,4* .•;%# p '••% y^':^-'\ /"'-'^X .''"''j^'S ,/.-^i.\ /.c^-*°o < 4^ 4^ « <^ *'7Vi» ,0 ^°-V^ V -^<2«. . ,0 -^^•^^*.^^ o^-,y^«^.-^o -V^-^Wf.*y ,/ ^.^^'Z \-^-^\/ '-o/'^^-.o' -^^ IC^ 8937 Bureau of Mines Information Circular/1983 Phosphate Rock Availability—Domestic A Minerals Availability Program Appraisal By R. J. Fantel, D. E. Sullivan, and G. R. Peterson UNITED STATES DEPARTMENT OF THE INTERIOR .f^J^MJ^^ S^'^i!!ff!l^J^^ Information Circular] 8937 Phosphate Rock Availability— Domestic A Minerals Availability Program Appraisal By R. J. Fantel, D. E. Sullivan, and G. R. Peterson UNITED STATES DEPARTMENT OF THE INTERIOR James G. Watt, Secretary BUREAU OF MINES Robert C. Norton, Director This publication has been cataloged as follows: ^\\ 2 '\'> "t ^^^ Fantel, R. J. (Richard J.) Phosphate rock availability— domestic. (Information circular / Bureau of Mines ; 8937) Includes bibliographical references. Supt. of Docs, no.: I 28.27:8937. 1. Phosphate rock — United States. I. Sullivan, Daniel E. II. Pe- terson, Gary R. III. Title. IV. Series: Information circular (United States. Bureau of Mines) ; 8937. TN295.U4 fTN914.U5l 622s [333.8'5] 83-600069 PREFACE The Bureau of Mines is assessing the worldwide availability of nonfuel minerals. The Bureau identifies, collects, compiles, and evaluates in- formation on active, developed, and explored mines and deposits, and on mineral processing plants worldwide. Objectives are to classify domes- tic and foreign resources; to identify by cost evaluation, resources fO that are reserves; and to prepare analyses of mineral availabilities. :::; This report is part of a continuing series of reports that analyze the availability of minerals from domestic and foreign sources and the factors affecting availability. Analyses of other minerals are in prog- ress. Questions about these reports should be addressed to Chief, Divi- :^ sion of Minerals Availability, Bureau of Mines, 2401 E St., NW. , Wash- ^ ington, D.C. 20241. ro I Ill CONTENTS Page Preface 1 Abstract 1 Introduction 2 Acknowledgments 4 The domestic phosphate Industry 4 Evaluation methodology 6 Geology of domestic phosphate deposits 11 The Southeast 11 Tennessee 15 The West 15 Domestic phosphate resources 17 The Southeast 17 Tennessee 20 The West 20 Domestic phosphate mining and benef Iclatlon methods 23 Domestic phosphate costs 26 Comparison of southeastern and western resources 28 Availability of domestic phosphate resources 29 Total availability 29 Potential annual availability 33 Conclusions 35 References 36 Appendix A. — Domestic phosphate deposit status and ownership 38 Appendix B. — The Zellars-Wllllams cost model for Florida phosphate — description of typical cases 40 Appendix C, — Domestic phosphate regulatory and environmental constraints and permitting 56 ILLUSTRATIONS 1 . Phosphate rock uses 2 2. Domestic phosphate rock consumed In 1980 3 3 . Integration of Idaho phosphate deposits 6 4 . Flow chart of MAS evaluation procedure 8 5. Mineral resource classification categories 8 6. Southeastern U.S. phosphate districts 13 7. Location of Tennessee phosphate deposits 15 8. Location of Western U.S. phosphate deposits 16 9. Area coverage In the Central Land-Pebble District (Including the southern extension) , Florida 19 10. Isopach map of the overburden overlying the Hawthorn Formation In Florida. 21 11. Isopach map of the Hawthorn Formation In Florida 22 12. Typical process flowsheet, Southeastern United States 23 13. Typical process flowsheet, Western United States 25 14. Phosphate rock potentially recoverable from all domestic deposits 30 15. Phosphate rock potentially recoverable from all Florida and North Carolina deposits 30 16. Phosphate rock potentially recoverable from all western deposits 31 17. Phosphate rock potentially recoverable from all domestic deposits, at selected grade ranges 31 18. Phosphate rock potentially recoverable from producing mines and nonproduc- ing deposits 33 IV ILLUSTRATIONS—Continued Page 19. Potential annual availability of phosphate rock from producing mines.... 34 20. Potential annual availability of phosphate rock from nonproducing deposits 35 TABLES 1. U.S. phosphate rock production 3 2. Deposit characteristics of Southeastern U.S. phosphate districts 12 3. Summary of Southeastern U.S. demostrated phosphate resources 18 4. Additional phosphate resources, Southeastern United States 18 5. Summary of Western U.S. demonstrated phosphate resources 21 6 . Operating costs for domestic phosphate operations 27 7. Estimated capital costs to develop nonproducing phosphate deposits in the United States 28 8. 1981 phosphate rock prices -»,,, 32 B-1. Mining and milling production cost summary 41 B-2. Production cost of typical large mine in higher quality ore (case I).... 41 B-3. Production cost of typical medium-sized mine in higher quality ore (case 11) 42 B-4. Production cost of typical medium-sized mine in higher quality ore (case IIA) 43 B-5. Production cost of typical small mine in higher quality ore (case III).. 44 B-6. Production cost of typical large mine in lower quality ore (case IV).... 45 B-7. Production cost of typical small mine in lower quality ore (case V) 46 B-8. Operating parameters for average mine (case I) 47 B-9. Operating parameters for average mine (case II) 48 B-IO. Operating parameters for average mine (case IIA) 49 B-11. Operating parameters for average mine (case III) 50 B-12. Operating parameters for average mine (case IV) 51 B-13. Operating parameters for average mine (case V) 52 B-14. Capital costs of typical large mine in lower quality ore (case IV) 54 B-15. Capital costs of typical small mine in lower quality ore (case V) 55 PHOSPHATE ROCK AVAILABILITY-DOMESTIC A Minerals Availability Program Appraisal By R. J. Fantel, ^ D. E. Sullivan,^ and G. R. Peterson-^ ABSTRACT To determine the availability of phosphate rock from domestic re- sources, the Bureau of Mines evaluated the potential production of phos- phate rock from the demonstrated resources of 130 mines and deposits. The evaluation included an estimation of resources, engineering methods, and capital and operating costs, and an economic analysis to determine each operation's average total cost of production over the life of the mine, including a 15-pct discounted-cash-f low rate of return on all investments. Quantified but not evaluated in this report are sub- stantial phosphate resources at the inferred and hypothetical resource levels. The 130 mines and deposits contain 6.4 billion tons of recoverable phosphate rock product, about 20 pet from producing mines. At total production costs of under $30 per ton in January 1981 dollars, about 1.3 billion tons of phosphate rock product is potentially available, over 90 pet from producing mines. This study suggests that production from low- cost, high-grade phosphate mines now in operation will decline during the next decade, and new higher cost, lower grade mines will have to be developed to satisfy demand into the next century. In addition to the demonstrated resources evaluated in this study, 7 billion tons of inf erred-level and 24 billion tons of hypothetical- level phosphate rock are potentially recoverable, which, in part, in- cludes material containing high amounts of magnesium. Much of this material could likely become available in the near future. 'Geologist. o ■'Economxst. -^Mineral economist. Authors are with the Minerals Availability Field Office, Bureau of Mines, Denver, Colo. INTRODUCTION Nitrogen, phosphorus, and potassium are the three primary nutrients necessary for plant growth. When these elements are either lacking or depleted from the soil, their addition is necessary to obtain higher agricultural yields. The only practical commercial source of phosphorus is phosphate rock. Phosphate ore consists of the calcium phosphate mineral apatite with quartz, calcite, and dolomite, along with clay and iron oxide minerals as the gangue. Industry practice, which is followed in this study, uses "phosphate rock" to refer to the beneficiated product of phosphate ore rather than to the in situ material. After benef iciation, phosphate rock ranges from 26 to about 34 pet P2O5 (phosphorus pentoxide) . Phosphate rock can be converted to phosphoric acid by the chemical "wet" process, or to ele- mental phosphorus in an electric furnace. The quality of phosphate rock for the o •H 4-> O 3 XI u CO B S-i 0) H PHOSPHATE ROCK Defluorination ->• Animal feeds Grinding Acidulation (H_SO, , — 2 4) Acidulation (HNO )2/- Acidulation (H^PO, ) J 4 FERTILIZERS : Direct application Normal superphosphate Nitric phosphates Triple superphosphate Ammonium phosphates Direct application PHOSPHORIC ACID ELEMENTAL PHOSPHORUS and sometimes other acids, — HCl is used in a few cases. HNO could also be used. Various INDUSTRIAL AND FEED CHEMICALS FIGURE 1. - Phosphate rock uses. (Courtesy Stanford Research Institute Internat.ional .) "wet" process is affected by the con- tained amounts of aluminum, iron, and magnesium. Presently, phosphate rock containing more than about 1.0 pet mag- nesium oxide or more than about 3.5 pet iron oxide plus aluminum oxide may cause problems in the mnaufacture of acids. Phosphate rock (fig. 1) is used to pro- duce wet-process phosphoric acid, elec- tric furnace elemental phosphorus, and animal feed supplements, and is ground for direct application to acidic soil (2^). 4 Phosphoric acid can be converted to ammonium phosphates and other ferti- lizers. Figure 2 illustrates the con- sumption pattern of phosphate rock in the United States in 1980. Nearly 90 pet of the phosphate rock consumed in that year was used in agriculture, mainly in the manufacture of phosphoric acids for fer- tilizer (9). Of key importance is the fact that phosphorus is not recovered by recycling; hence, the total supply must come from the mine production of phos- phate rock. No substitute for phosphate fertilizers can be produced in the quan- tities required to sustain world agri- cultural production. Underlined numbers in parentheses re- fer to items in the list of references preceding the appendixes at the end of this report. TABLE 1. - U.S. phosphate rock pro- duction, 1 million metric tons 1960 1970 1980 Southeastern States2,,, Tennessee 12.5 2.0 3.3 28.4 2.9 3.9 47.2 1.6 Western States^ 5.6 Total 17.8 35.2 54.4 "phosphate rock refers to beneficiated product. 2Florida and North Carolina. ^ Idaho, Utah, Montana, Wyoming, and California (1970). Sources: Stowasser (14); Bureau of Mines Mineral Industry Surveys, Market- able Phosphate Rock — February 1981; and the Phosphate Rock chapters of the 1962 and 1971 editions of the Bureau of Mines Minerals Yearbook (v. 1). The United States produced over 54 million tonsS of phosphate rock in 1980 (table 1), accounting for approximately 40 pet of total world output. Approxi- mately 26 pet of this production was exported and an additional 33 pet was converted to wet acid and exported as fertilizer and chemicals (16). The other two main phosphate rock producers are the U.S.S.R. and Morocco, which produced ^Unless otherwise noted, "tons" report refers to metric tons. in the U.S. demand 100% (40,305) Industrial 10.6% (4,273) Agriculture 89.4% (36,032) Fcrrophosphorus 0.5% (190) Elemental phosphorus 10.1% (4,083) Direct Phosphoric Triple Normal Defluorinated applications acid superphosphate superphosphate rock 0.1% (37) 84.1% (33,884) 3.3% (1,348) 0.8% (333) 1.1% (430) FIGURE 2. - Domestic phosphate rock consumed in 1980, in thousand metric tons. (Modified from reference 9 with data from reference 13, table 6.) approximately 25 and 21 million tons of phosphate rock, respectively. Cumula- tively, these three countries accounted for approximately three-fourths of world production in 1980. Although the U.S. Government does not maintain a phosphate rock stockpile, private companies main- tain stockpiles which may amount to about 25 pet of production. The major foreign markets for phosphate rock are Western and Eastern Europe and Asia. In 1978, Western Europe imported more than 21 million tons. Eastern Europe more than 10 million tons, and countries in Asia almost 7 million tons. In the United States phosphate is traded both as rock product and in the upgraded chemical forms. Although in the past Morocco produced primarily phosphate rock, processing facilities are being expanded to increase phosphoric acid and processed phosphate production. Phosphate North Carol turing phos (although ro calcining) . Tennessee i naces to e acid-grade Idaho, Utah, rock produced in Florida and ina is suitable for manufac- phoric acid and fertilizer ck in North Carolina requires Phosphate rock produced in s processed in electric fur- lemental phosphorus. Some phosphate rock produced in and Montana is also calcined before processing to produce acids. Furnace-grade phosphate rock produced in the West is reduced from the ore to ele- mental phosphorus in electric furnaces. The United States has traditionally been the world's largest net exporter of phosphate rock and related fertilizer products. Over the past several years, however, continuing exports of phosphate rock from Florida have become the subject of controversy. Some industry sources content that Florida has enough phosphate to supply the domestic and export markets for almost 300 years at current rates of production, assuming a gradually rising price and using present and new technol- ogy (11) , Conversely, William Stowasser, Bureau of Mines Phosphate Commodity Specialist and the General Accounting Office (GAO) forecast that by the turn of the century the United States may cease exporting phosphate rock (11). This report is part of a continuing series in which the availibility of min- erals from domestic and foreign sources and the factors affecting availability are analyzed. The importance of phos- phorus in agricultural production under- scores the need to determine the poten- tial availability of phosphate rock from domestic resources. I ACKNOWLEDGMENTS The authors thank William F. Stowasser of the Bureau of Mines, Division of Non- ferrous Metals; James B. Cathcart of the U.S. Geological Survey; and John P. Bernardi of International Minerals and Chemical Corp. , for their assistance. Production and cost data for the deposits analyzed were developed at Bureau of Mines Field Operations Centers in Denver, Colo., Pittsburgh, Pa., and Spokane, Wash, The Minerals Availability Field Office in Denver performed the economic evaluations on the properties and pre- pared this report. THE DOMESTIC PHOSPHATE INDUSTRY Most of the phosphate rock produced in the United States is used to manufacture wet-process phosphoric acid. Because phosphate rock is relatively low in water solubility, it is converted to chemical components for fertilizer application. The wet process produces phosphoric acid by digesting the apatite mineral in sulfuric acid, Diammonium phosphate (DAP), a common bulk blending-grade fer- tilizer chemical, is produced by reacting phosphoric acid with ammonia. If the phosphate rock is attacked with phos- phoric acid, triple superphosphate (TSP) is produced. When wet-process phosphoric acid is subjected to evaporation, a higher concentration of phosphoric acid is produced; when reacted with ammonia, phosphoric acid produces a liquid ammo- nium phosphate fertilizer ( 23 ) . The Midwestern States (particularly the Corn Belt) consume approximately half of all the fertilizer used in the United States. The other half is split nearly evenly between the Western and Eastern States, Phosphate fertilizer is consumed mainly to produce beans, corn, cotton, cereal grains, and soybeans (9). Phosphate animal feed supplements are produced by the def luorinization of either phosphate rock or phosphoric acid. Lime is reacted with def luorinated phos- phoric acid to produce dicalcium phos- phate. These phosphate animal feeds are used to increase the nutritional quality of livestock feed (23). Elemental phosphorus is produced by reducing phosphate rock in an electric furnace plant and marketed as is , or oxi- dized to produce phosphoric acid and anhydrous derivatives. Approximately 50 pet of elemental phosphorus produced is used to produce sodium tripolyphosphate, a detergent builder. The potential byproducts fluorine, phosphogypsum, uranium, and vanadium in phosphate rock were not considered in this study. More than 20 companies mined and pro- cessed phosphate rock in the United States in 1980. Firms in Florida and North Carolina include Agrico Chemical Co. , Amax Phosphate, Inc. , Brewster Phos- phates, C. F. Industries, Inc., Gardin- ier. Inc., W. R. Grace and Co., Interna- tional Minerals and Chemical Corp. (IMC), Mobil Chemical Co. , Estech General Chemi- cal Co., USS Agri-Chemicals, Occidental Chemical Co., and Texasgulf , Inc; those in Idaho, Montana, and Utah are Conda Partnership, Monsanto Industrial Chemi- cals, J. R. Simplot Co., Stauffer Chemi- cal Co. , Cominco American, Inc. , and Chevron U.S.A.; Tennessee firms include Hooker Chemical Co. , Monsanto Industrial Chemicals Co. , and Stauffer Chemical Co. (16). Other companies are presently develop- ing domestic deposits, some of which pro- duced in 1981-82, and others of which will be producing in the near future. They include Beker Phosphate Corp. Farm- land Industries, Inc., in Florida, and North Carolina Phosphate Corp. in North Carolina. Numerous other companies have explored deposits throughout the United States, many of which were considered in this study (appendix A). The domestic phosphate industry exhib- its a high degree of vertical integration and is highly concentrated: 15 companies supplied over 95 pet of the country's phosphate rock production during the 1970's (J_4, p. 3). Once mined and benef iciated, phosphate rock is transported either to a phos- phoric acid or elemental phosphorus plant, or to a port for export. The rock is most commonly shipped by rail, although occasionally it is shipped by truck or slurry pipeline for short dis- tances, or by barge for seaway hauls. In Florida, most rock is sent either to nearby acid plants or directly to the port of Tampa for export or shipment to domestic users; some also goes to port at Jacksonville. Products from the acid plants are also shipped by rail to the ports of Tampa or Jacksonville for either export or shipment to domestic users. Most of the rock mined in Florida is pro- cessed within the State, In North Caro- lina, most of the rock is used to manu- facture phosphoric acids for export or shipment to domestic users from the port at Morehead City, In 1978 approximately 70 pet of Florida and North Carolina rock was used for domestic markets (mainly in the East and Midwest), and the remaining 30 pet was exported (9), All phosphate rock in Tennessee is used to manufacture elemental phosphorus at plants in the Columbia and Mount Pleas- ant, Tenn. , areas. In Idaho, phosphate rock is used to produce phosphoric fertilizer and elemental phosphorus. A.cid is produced primarily in Pocatello or Conda, Idaho; elemental phosphorus is produced primar- ily in Soda Springs and Pocatello, Idaho, and Silverbow, Mont. Figure 3 shows the disposition of Idaho phosphate rock. Deposits in Utah and Wyoming produce, or would produce, rock used for manufac- turing acid and phosphorus. The Vernal Mine in Utah ships most of its phosphate rock out of the State for processing. It was assumed for the purposes of this study that if processing plants were not built on site or nearby, the acid-grade rock from the nonproducing deposits in Utah and Wyoming could be processed in Pocatello, Idaho; and furnace-grade rock for elemental phosphorus production in Soda Springs, Idaho. Approximately 80 pet of all western rock is consumed domestically, mainly in the Western States (13). EVALUATION METHODOLOGY For this study, 130 domestic mines and deposits were examined. These deposits include resources of phosphate rock at the demonstrated level that met the cri- teria of this study (listed below) and could be mined and beneficiated with cur- rent technology. The reserve and re- source tonnage and grade calculations included in this study were derived from company data, published and unpublished sources, contractor-supplied information, and Bureau of Mines estimates. Typically, beneficiated phosphate rock contains 7 to 20 pet moisture. Currently, most processes to convert CONDA MINE GAY MINE HENRY AND NORTH HENRY MINES H M L '- L|J Processing ( Simplot at Conda ) Washing plant, . . calclner S— S ( Simplot and FMC ) H M L 1— ^L^Prc Stockpile on site -*- Processing Processing FMC at Pocatello Calciner , phosphorus plant (Valley Nitrogen At California) Fertilizer plant Processing ( Simplot at Pocatello ) Calciner, fertilizer plant MAYBE CANYON MINE Conda partnership H M L l-J Processing ( Conda partnership at Conda ) Washing plant, ^ calciner I ^Processing Processing ( Beker at Conda ) Fertilizer plant- Monsanto H M L Processing ( Monsanto at Soda Springs ) Calciner, phosphorus plant PHOSPHORUS CHEMICAL MANUFACTURERS WOOLEY VALLEY MINE (Stauffer) H M L U ^ Processing ( Stauffer at Leefe ) Washing plant, calciner (Western at Alberta) Fertilizer plant } Processing ( Stauffer at Silverbow ) Calciner, phosphorus plant Processing ( Stauffer at Garfield ) Fertilizer plant (H-High grade, M-Medium grade, L-Low grade) FIGURE 3. - Integration of Idaho phosphate deposits. phosphate rock into its numerous end uses will accept wet rock feed, although less than 3 pet moisture is desirable. The final product in this study is dry phos- phate rock sold f.o.b. mill. In this form, phosphate rock is used in chemical processes that create a number of prod- ucts. The f.o.b. mill value was the com- mon basis that was acceptable for this study; therefore the additional costs for further processing the phosphate rock into its many end products were not in- cluded. Transportation charges, although discussed in the report, are not included in the economic evaluations of individual phosphate properties. For this study, the term "phosphate rock" refers to the beneficiated product, and "phosphate ore" refers to the minable material in the ground. Reserves and resources expressed in terms of phosphate ore or rock are stated in dry tons. The analysis methodology of this study follows: 1. The quantity and grade of domestic phosphate ore resources were evaluated in relation to physical and technological conditions that affected production from each deposit as of the study date, Janu- ary 1981. 2. The capital investments and operat- ing costs for appropriate mining, concen- trating, and processing methods were estimated for each mine or deposit in January 1981 dollars. 3. An analysis of each operation de- termined the total tonnage of phosphate rock at its associated production cost that could potentially be recovered at specific production levels for each deposit. 4. After completion of the individual property analyses, all properties in- cluded in the study were simultaneously analyzed and aggregated into phosphate rock availability curves. These curves illustrate each operation's potential phosphate rock production at its average total cost of production. The average total cost of production for each opera- tion represents its "incentive price" to produce phosphate rock: the price at which a firm would be willing to produce phosphate rock over the long run, where revenues are sufficient to cover the average total cost of production, includ- ing a return on investment high enough to attract new capital (1). The rate of return used in this study is a 15-pct discounted-cash-f low rate of return (DCFROR) on the total investments of each operation. The data collected for this report are stored, retrieved, and analyzed in a com- puterized component of the Bureau's Min- erals Availability System (MAS). After a deposit was selected for analysis, an evaluation of the operation was begun. The flow of the MAS evaluation process from deposit identification to develop- ment of availability information is illustrated in figure 4. Information on the individual phosphate mines and deposits included in this study is in appendix A. Selection of deposits was limited to known deposits that have significant demonstrated reserves or resources. Reserves are miaterial that can be mined, processed, and marketed at a profit under prevailing economic and technologic conditions. Resources are concentrations of naturally occurring solid, liquid, or gaseous materials in or on the Earth's crust in such form that economic extraction of a commodity is currently or potentially feasible (19). For the deposits analyzed, tonnage estimates were made at the demonstrated resource level based on the mineral resource-reserve classification system developed jointly by the Bureau of Mines and the U.S. Geological Survey (19). The demonstrated resource category in- cludes measured plus indicated tonnages (fig. 5). dentif on cation d j~ Mineral ^ Indu st r ies 1 1 Location 1 ' System 1 1 (MILS) 1 1 data J < MAS computer data base se 1 e ction of deposits Tonnage and grade determination '-• — ¥ 1 Enginee ring and cost evaluation ^ ' ^ Deposit report preparation MAS per manen t deposit f i Ies r 1 t Data selection and va I idation Taxes, royalties, cost indexes, prices, etc. Variable and parometer adjustments Economic analysis Datol Sensitivity analysis Availability I curves Anolyticol reports u w Doto Avaikibtllty curves Analytical reports FIGURE 4. - Flow chart of MAS evaluation procedure. Cumulative production IDENTIFIED RESOURCES UNDISCOVERED RESOURCES Demonstrated Inferred Probability range '-r\ Measured Indicated Hypothetical • Speculative ECONOMIC - - 1 -F -F - MARGINALLY ECONOMIC - SUB- ECONOMIC other occurrences Includes nonconventional and low-grade materials FIGURE 5. - Mineral resource classification categories. To be included in the analysis, phos- phate deposits had to meet technological criteria representing current acceptable industry standards. The criteria shown below for the southeastern deposits should be viewed as "guidelines" rather than an absolute lower limit ( 20 ) : 1. Deposit size must be more than 5 million tons of recoverable phosphate rock, 6 and that tonnage must be within an average radius of 1,5 miles^ from the center of the ore body. 2. Deposit size must be more than 10 million tons if the average overburden thickness is more than 6 m, and that ton- nage must be within an average radius of 2 miles of the center of the ore body. 8 3. Deposit size must be greater than 15 million tons if the overburden average thickness is more than 9 m, and that ton- nage must be within an average radius of 2.5 miles from the center of the ore body. 9 4. The flotation feed grade must be more than 4.6 pet P2^5* 5. The concentrate grade must be more than 27.5 pet P2^5' 6. The phosphate concentration must be 1 ton of recoverable product per 8 cu m of ore. 7. The ore zone must be more than 1.5 m thick. ^Exceptions — if the deposit is adjacent to larger identified deposits or is in hardrock areas. 'This radius equates to the resource ore body covering one-half of the area of the deposit, at an average of 2,500 tons per acre. °See footnotes 6 and 7 for exceptions and definitions. ^See footnotes 6 and 7 for exceptions and definitions. 8. Phosphate rock product must contain less than 1.5 pet magnesium oxide (MgO). (Resources of high-MgO phosphate deposits were quantified in this report, and tech- nological developments are discussed, but deposits containing greater than 1.0 pet MgO are not evaluated in this study.) The following criteria for developing resource estimates of Tennessee phosphate represent a range the central Tennessee phosphate companies recognize as repre- senting acceptable minable deposits (22): 1. A minimum cutoff grade range of 16 to 17.2 pet P2O5. 2. Minimum ore thickness range of 0.6 to 1.2 m. 3. Maximum overburden-to-ore range of 3:1 to 4:1. ratio 4. A minimum ore body size of 22,675 dry tons of phosphate rock. The average ore body is small (150,000 to 1.2 million tons), which means that deposits at a number of separate locations may have to be mined to satisfy one company's annual requirement. The study criteria for explored depos- its in Utah and Wyoming include a minimum ore thickness of 0.91 m and a minimum average grade of 18 pet P2O5. For eco- nomic classification, minable resources were further subdivided by depth, thick- ness, dip, grade, and probability of occurrence. Resources above adit entry levellO were estimated and economically evaluated after site-specific corrections were applied. The quantity of resources occurring below adit entry level was not costed or economically evaluated in this study because of their extremely high recovery cost. ^'-'Adit entry level is defined as the nearly horizontal access to the minable resource. The adit level also serves as a conduit for natural water drainage. 10 Evaluation of each phosphate property included determinations of phosphate resources, deposit development, technol- ogies, and costs. Information on the average grades, ore tonnages, and differ- ent physical characteristics affecting production from domestic phosphate depos- its was obtained from numerous sources, including Bureau of Mines and Geological Survey publications, professional jour- nals. State and industry publications, annual reports, company lOK reports and prospectuses filed with the Securities and Exchange Commission, data made avail- able to the Bureau of Mines by private companies or under contracts, and esti- mates made by Bureau of Mines person- nel based on personal knowledge and judgments. Capital expenditures were calculated for exploration, acquisition, develop- ment , mine plant and equipment , and con- structing and equipping the mill plant. Capital expenditures for mining and pro- cessing facilities include the costs of mobile and stationary equipment, con- struction, engineering, facilities and utilities, and working capital, A broad category, facilities and utilities (infrastructure), includes the cost of access and haulage facilities, water facilities, power supply, and personnel accommodations. Working capital is a revolving cash fund required for such operating expenses as labor, supplies, taxes, and insurance. Mine and mill operating costs were also calculated for each deposit. The total operating cost is a combination of direct and indirect costs. Direct operating costs include materials, utilities, pro- duction and maintenance labor, and pay- roll overhead. Indirect operating costs include technical support and clerical labor, administrative costs, facilities, maintenance and supplies, and research. Other costs in the analysis are fixed charges including local taxes, insurance, depreciation, deferred expenses, interest payments (if applicable) , and return on investment. The Bureau of Mines has developed the Supply Analysis Model (SAM) to perform DCFROR analyses to determine the price of the primary commodity required for an operation to obtain a specified rate of return on all of its investments (6), This determined value for the phosphate rock price is equivalent to the average total cost of production for the opera- tion over its producing life under the set of assumptions and conditions (e.g, , mine plan, full-capacity production, and a market for all output) that are neces- sary in order to make an evaluation. The DCFROR is most commonly defined as the rate of return that makes the present worth of cash flow from an investment equal the present worth of all after-tax investments (12, p, 232), For this study, a 15-pct DCFROR was considered the necessary rate of return to cover the opportunity cost of capital plus risk. Based on the MAS methodology, all capi- tal investments incurred 15 years before the initial year of the analyses (January 1981) are treated as sunk costs. Capital investments incurred less than 15 years before January 1981 have the undepreci- ated balances carried forward to January 1981, with all subsequent investments reported in constant January 1981 dollar terms. This computation means that for producing operations, the undepreciated capital investment remaining in 1981 was calculated. All reinvestment, operating, and transportation costs are expressed in January 1981 dollars. No escalation of either costs or prices was included be- cause it was assumed that any increase in costs would be offset by an increase in prices, A separate tax-records file, maintained for each State, contains the relevant fiscal parameters under which the mining firm would operate. This file includes corporate income taxes, property taxes, and any royalties, severance taxes, or other taxes that pertain to phosphate rock production. These tax parameters are applied to each mineral deposit under evaluation, with the implicit assumption 11 that each deposit represents a separate corporate entity. The system also con- tains an additional file of economic indexes to allow for continuous updating of all cost estimates to the base date of the study. Beginning with 1981, the first year of the analysis, detailed cash-flow analyses were generated for each preproduction and production year of an operation. Upon completion of the individual property analyses, all properties included in the study were simultaneously analyzed and aggregated onto resource-availability curves. The total resource-availability curve is a tonnage-cost relationship that shows the total quantity of recoverable product potentially available at each operation's average total cost of pro- duction over the life of the mine, deter- mined at the stipulated (15-pct) DCFROR. Thus, the curve is an aggregation of the total potential phosphate rock that could be produced over the entire producing life of each operation, ordered from operations with the lowest average total cost of production to those with the highest. The curve provides a concise, easy-to-read, graphic analysis of the comparative costs associated with any given level of potential total output and provides an estimate of what the average long-run phosphate price (in January 1981 dollars) would likely have to be for a given tonnage to be potentially avail- able. Three types of curves can be gen- erated: (1) total-availability curves, (2) annual curves for selected years, and (3) annual curves at selected cost levels. Certain assumptions are inherent in the curves. First, all deposits produce at full operating capacity throughout the productive life of the deposit, and this capacity remains constant unless planned expansions were known. Second, each operation is able to sell all of its out- put at a price equal to or greater than the average total production cost. Third, development of each nonproducing deposit began in the same base year (N). Since it is difficult, if not impossible, to predict when the explored deposits are going to be developed, this assumption was necessary. Also, the preproduction period allows for only the minimum engin- eering and construction period necessary to initiate production under the proposed development plan. Consequently, the additional time lags and potential costs involved in filing environmental impact statements, receiving required permits, financing, etc. , have not been included in the individual deposit analyses. GEOLOGY OF DOMESTIC PHOSPHATE DEPOSITS THE SOUTHEAST Phosphate deposits in Florida and North Carolina are part of a phosphate province that extends from southern Florida north into Virginia. Most phosphate was depos- ited in rocks of Middle Miocene age (the Hawthorn and equivalent formations). These rocks underlie much of peninsular Florida and the Atlantic coastal plain. During the Upper Miocene and into the Pliocene the phosphate of the Hawthorn Formation was reworked, concentrated, and enriched and redeposited in the Bone Valley Formation (of Upper Miocene to Pliocene age). Redeposition also oc- curred in channelike deposits of Pleisto- cene age. Phosphate in the Hawthorn and equivalent formations was deposited when cold, phosphorus-enriched marine water welled up onto a shallow warm-water pla- teau or when cold, along-shore currents were turbulently mixed with warmer wa- ters, and phosphorus was precipitated. Structural features in the coastal plain partially controlled the deposition. The deposits are located in basins on the flanks of anticlines which were rising at that time; deposition occurred mainly in these basins. In central and southern Florida the Ocala Uplift and the Hills- borough High were the controlling fea- tures depositing phosphate on their flanks, whereas in northern Florida the Ocala Uplift was the main factor. In North Carolina, the Albemarle Embajonent and an unnamed high were responsible (4). 12 Phosphate deposits in the Bone Valley Formation are composed of phosphate par- ticles (ranging from pebble to clay size), quartz grains, carbonate grains, and clay minerals. The phosphate mineral is a carbonate-f luorpatite. Fine sand, sand, and pebble-size material can be recovered; silt and clay-size particles are too fine to recover economically with current technology. The amount of pebble (+1 mm size) in Bone Valley Formation deposits is important because most of the pebble is an economic product after sim- ple screening. Therefore, the higher the pebble content of the phosphate ore, the less benef iciation is required on the remainder, resulting in lower overall operating costs. The principal phosphate districts in the Southeast (fig. 6) are the Central Land-Pebble District of Florida (which includes the "southern extension"), the North Florida District (which extends into Georgia) , and the Pungo River Phos- phorite District of North Carolina. The Ridgeland Basin phosphorites in South Carolina (which includes the Savannah River deposits of Georgia) were not eval- uated for this study since they currently are defined at the identified resource level only. Because of their proximity, Florida's east coast deposits are dis- cussed along with the deposits in north- ern Florida. The Florida Hardrock District is currently of minor im- portance because no active mining has occurred since 1966 other than reworking phosphatic clay wastes from prior mining operations (_7 ) . A summary of the physi- cal characteristics of these districts is shown in table 2. The Central Land-Pebble District, the most important district in all the Southeast, has been the largest source of phosphate in the world for many years. It includes Polk and Hillsborough coun- ties, where 18 producing mines and 13 nonproducing deposits were evaluated. In recent years there has been much activity towards extending this district south (the southern extension) to include phosphate resources in DeSoto, Hardee, Manatee, and Sarasota counties. Of the 27 deposits in the southern extension evaluated in this study, only 1 is cur- rently producing (although another is developing). Only the portions of the deposits considered minable with current technology were evaluated, although the other resources not considered recovere- able with current technology (par- ticularly high MgO resources) were quantified. In the Central Land-Pebble District, the Bone Valley Formation of Upper Mio- cene age and the leached surficial part of the Hawthorn Formation are mined. The Bone Valley Formation changes facies to the south and contains little or no phos- phate in the southern extension, and only the upper clastic unit of the Hawthorn Formation is minable in that area. TABLE 2. - Deposit characteristics of Southeastern U.S. phosphate districts (20) Central Southern Florida North East Pungo River Florida Land-Pebble Florida Extension Hardrock Florida- Georgia Florida Coast Phosphorite, North Carolina Overburden thickness. . .m. . 6-9 6-12 3-8 6-15 15-46 27-40 Ore zone thickness. . .m. . 5-8 5-11 2-9 3-8 2-15 12-15 Pebble product pet.. 20-60 10-25 60-100 10-20 NA P2O5 product pet. . 31-33 30-31 30-35 30-33 28-30 30-31 MgO product pet. . 0.5 0.8 NA 0.75 0.9-2.0 0.5 NA Not available, 13 LEGEND Phosphorite deposit IN- 1 -^-'-Pungo River phosphorite district South Carolina district Ridgeland basin phosphorite district Georgia-Florida district Land-pebble district 100 200 mi T--H H 100 200 300 km FIGURE 6. - Southeastern U.S. phosphate districts. (Modified from reference 4.) 14 The deposits in the Central Land-Pebble District have ore zones ranging from 5 to 8 m thick, with an overburden of 6 to 9 m. In the southern extension deposits, the ore zones are 5 to 11 m thick, and the overburden is 6 to 12 m thick. In both the central and southern extension areas, the overburden-to-ore ratio is less than 2:1. Farther south, the over- burden and ore zones become progressively thicker until at some point the total depth is too great for mining by current technology. The percentage of pebble in product for Central Land-Pebble District deposits is 20 to 60 pet, whereas the deposits in the southern extension average considerably less (10 to 25 pet), and the pebble frac- tion in the southern deposits contains high amounts of calcite and dolomite (the magnesium-bearing mineral). The average P2O5 content of the product is 31 to 33 pet in the Central District but 30 to 31 pet in the south. The iron-aluminum oxide percentage in the product in both areas is within acceptable limits (less than 3.5 pet). The hardrock deposits of Florida lie along the east limb of the Oeala Uplift or Arch. Although they had been produc- ing since about 1900, there has been no significant mining activity since the mid-1960' s. The irregularly sized depos- its occur as small pods in this northwest-southeast-trending district. The deposits are complex in origin. They were derived from the Hawthorn Formation and are in rocks of post-Hawthorn age in the so-called Alachua Formation, which includes rocks of Upper Miocene, Plio- cene, Pleistocene, and Holocene age. Ore thickness in the deposits ranges from 2 to 9 m; overburden ranges from 3 to 8 m (approximately a 1:1 overburden-to-ore ratio). The percentage of coarse rock (pebble, lump rock, plate rock, etc.) in the ore is very high, ranging from 60 to 100 pet; the P2O5 content of the product is also high, ranging from 33 to 35 pet. Although the percentage of magnesium oxide is minor, the iron and alumi- num content can be considerable. The Hardrock District includes deposits in Citrus, Lafayette, and Marion Counties. This evaluation included five deposits, one of which is presently processing phosphatic clay wastes from prior mining operations (7). The North Florida deposits occur in Alachua, Bradford, Baker, Clay, Columbia, and Hamilton Counties. This evaluation includes eight deposits from four of these counties; the only two producing mines are in Hamilton County. The east coast deposits (of which only one, in Brevard County, was evaluated) are in- eluded here for discussion purposes. The North Florida deposits are in the Haw- thorn Formation and an unnamed upper Mio- cene formation equivalent in age to the Bone Valley Formation. The minable por- tion includes the upper part of the Haw- thorn Formation and the Upper Miocene strata. Ore thickness ranges from 3 to 8 m (2 to 15 m on the east coast), and overburden from 6 to 15m (15 to 46mon the east coast); thus the overburden- to-ore ratio is 2:1 in the north and 3:1 in the east. The pebble fraction of the product ranges from 10 to 20 pet in the north, but is almost nil on the east coast. The P2O5 content of the product averages 30 pet; the northern deposits may be as high as 33 pet and the eastern deposits as low as 28 pet. The percent magnesium oxide in the product is within the acceptable limit of less than 1 pet for the northern deposits, although some of the material on the east coast is very high in magnesium oxide, reflecting a somewhat higher content of dolomite. The east coast material would be difficult to beneficiate under present technological constraints. Two deposits in North Carolina were evaluated: Lee Creek is a producer, and the North Carolina Phosphate Deposit is under development. Both deposits are in Beaufort County within the Pungo River Phosphorite District and occur in the Middle Miocene Pungo River Formation, equivalent in age to the Hawthorn Forma- tion of Florida. The ore zone ranges from 12 to 15 m thick with 27 to 40 m of 15 overburden (overburden-to-ore ratio is more than 2:1). The small percentage of pebble is rejected from the product be- cause of contamination from shell mate- rial and dolomite. The product, nearly all derived from phosphatic sands, has a grade of approximately 30 pet P2^5* ^^^ iron and aluminum oxide content is ap- proximately 2 pet, and the magnesium oxide content is approximately 0.5 pet, both well within acceptable limits. TENNESSEE Phosphate has been produced from depos- its in Tennessee since 1900, although most deposits are nearly mined out. The three types of phosphate deposits in the State are the so-called brown rock, blue rock, and white rock. The only deposits considered for this study are the brown- rock type (the other types being insig- nificant or uneconomic); these occur mainly as "blanket deposits" derived from phosphatic limestones of Ordovician age. The deposits are residual, formed in the modern weathering cycle by acid leaching of the marine phosphatic limestones. The phosphate mineral in these deposits, a carbonate fluorapatite, occurs as sand- sized grains intermixed with clays (called muck) or as higher grade plates (called lump rock) (22). Overburden for these deposits averages 4 m in thickness, and the ore zones average 2m in thick- ness, (a 2:1 overburden-to-ore ratio). The phosphate ore grade ranges from 17 to 23 pet P2^5 ' whereas the benef iciated rock product grade ranges from 26 to 29 pet P205* All the deposits studied are centered around Maury County in the cen- tral portion of the State (fig. 7) (22). Most of the mines in Tennessee are very small, ranging from 150,000 to 1.2 mil- lion tons of production per year. Many separate deposits are mined concurrently to fulfill a company's production re- quirements. For this study, many of these deposits have been grouped, by com- pany, into individual evaluations. 25 50 mi 40 80 km MAP LOCATION FIGURE 7. - Location of Tennessee phosphate deposits. THE WEST The phosphate deposits of the Western United States are located in Idaho, Mon- tana, Utah, and Wyoming, with most of the present mining activity occurring in Idaho (fig. 8) (10) . The western depos- its occur in the Permian Phosphoria For- mation, with the phosphate rock composed primarily of carbonate fluorapatite pel- lets but also occurring in oolitic, piso- litic, nodular, and bioclastic forms. These deposits were apparently formed by cold, phosphorus-rich marine water upwelling into a large trough-platform environment adjacent to a continental margin. Phosphate-rich beds appear to reach their maximum thickness at the trough-platform boundary. The Phosphoria Formation consists of phosphorite, chert, limestone, mudstone, shale, and siltstone. Phosphate is mined 16 LEGEND ^ Active mines •^^ Phosphoria outcrop / / Idaho Falls >^ . *; .^ ^' ., . \o >\\\VLeefe \ Lander Soda Springs •t'/| \.j \ FIGURE 8. 100 200 km Location of Western U.S. phosphate deposits, (Modified from reference 10. 17 principally from the Mead Peak Member, primarily from its upper and lower zones. These two ore zones range in thickness from 9 to 18 m, and the middle waste rocks (mainly muds tones and carbonates) are typically 30 m thick. Overburden at these deposits, averaging only 5 to 10 m, consists of loose, unconsolidated sedi- ments. The upper phosphate zone tends to be high in phosphate content because of surface-rock weathering that leached out much of the carbonate. The zone averages 5 to 8 m in thickness, and phosphate con- tent ranges from 20 to 24 pet P2O5. The lower zone is much thicker, ranging in thickness from 9 to 12 m; its phosphate content ranges from 20 to 30 pet P2^5> increasing in value in the lower portions of the zone. The phosphate deposits of the Phos- phoria Formation are altered at the sur- face. The altered rocks have been suf- ficiently weathered to remove much of the aluminum, calcium, iron, and magnesium, resulting in lower grades for the dele- terious materials and higher P2O5 grades. These are the rocks that are currently being mined. The unaltered rocks have not been weathered and occur as much as 500 m below the surface (5). These rocks are not presently being mined because of their depth and because of the difficulty in processing them owing to the high amounts of impurities (CaC03, MgO, Fe, etc. ) that they contain. For these rea- sons, the unaltered resources are not included in this study. DOMESTIC PHOSPHATE RESOURCES Of the 130 mines and deposits evaluated for this study, 71 are in Florida, 2 in North Carolina, 5 in Tennessee, 8 in Idaho, 1 in Montana, 17 in Utah, and 26 in Wyoming. Fifty-six pet of these de- posits are in Florida and North Carolina and contain over 82 pet of the in situ ore and 60 pet of the recoverable phos- phate rock from demonstrated resources in the United States. Total domestic re- sources of phosphate ore from all the deposits evaluated at the demonstrated level are 28.2 billion tons containing 6.4 billion tons of recoverable phosphate rock. Following is a discussion of do- mestic phosphate resources, by region. THE SOUTHEAST As of January 1981, at the demonstrated resource level, almost 4 billion tons of phosphate rock was potentially recover- able from the southeastern deposits eval- uated (table 3). The deposits in the Central Land-Pebble District, where most mining occurs, account for less than 20 pet of this resource whereas the deposits in the southern extension contain almost 40 pet. Figure 9 shows the approxi- mate coverage of deposits evaluated for this study in the Central Land-Pebble District, including the southern exten- sion. The shaded area includes all the demonstrated resources considered min- able. The remainder of the resources within the area were classified as in- ferred or hypothetical. Much of this material is presently considered to be unacceptably high in magnesium oxide or is considered unminable with present technology. As shown in table 4, there is an estimated 5.9 billion tons of re- coverable phosphate rock in the Southeast at the inferred resource level and an additional 14.3 billion tons at the hypo- thetical level. A major difference between the deposits in the Central Land-Pebble District and those in the southern extension is the amount of magnesium oxide in the product. During phosphoric acid production, the different carbonate minerals consume sul- furic acid; increased amounts of magne- sium oxide in the phosphate rock feed increase this sulfuric acid consumption, and MgSO^ does not precipitate as does CaS04. Higher magnesium oxide content also increases the viscosity of the acid and causes problems in producing diam- monium phosphate. Florida phosphate rock has traditionally contained acceptable quantities of magnesium oxide; however, much of the phosphate resource potential from Florida (particularly the southern extension) occurs in deposits containing 18 TABLE 3. - Summary of Southeastern U.S. demonstrated phosphate resources (Quantities in million metric tons; all grades weighted-average percent P2O5) District and county In situ ore tonnage Extractable ore grade Recoverable rock product Rock product grade Central Florida Land- Pebble District: Hillsborough. Polk 900 2,519 7.5 8.0 150 500 33.1 31.6 Total or weight— average. ........ 3,419 7.9 650 32.0 Southern Florida extension: Hardee 4,710 6,383 1,175 5.8 4.7 4.9 599 692 145 30.9 Manatee ............................ 30.4 Others 1 30.2 Total or weight— average. 12,268 W 5.2 W 1,436 W 30.6 Florida Hardrock District: All counties^ W Northern and East-Coast Florida Districts: Columbia. ....•.•...••••............ 1,478 2,635 4.5 5.4 148 323 30.0 Others^ 30.0 4,113 W 3,488 5.1 W NAp 471 W 1,322 30.0 Pungo River, N.C. District W Other NAp Grand total or weight-average... 23,288 7.0 3,879 30.8 NA Not applicable since these deposits are in different districts of the southeast; therefore, weight average grades would not be relevant. W Withheld to avoid disclosing individual company confidential data; included as other. 1 1ncludes De Soto and Sarasota Counties. ^Includes Citrus, Lafayette, and Marion Counties. ^Includes Alachua, Bradford, Brevard, and Hamilton Counties. TABLE 4. - Additional phosphate resources. Southeastern United States (Million metric tons of recoverable phosphate rock) ' Georgia South Carolina Florida North Carolina Tota l ^Does^ not include recently discovered resources offshore (Savannah River, Blake Plateau, and Onslow Bay), which may potentially contain miany billions of tons of re- coverable phosphate rock. ^Tonnages shown for Georgia, South Carolina, and North Carolina are derived from the Zellars-Williams report on these States (21). Florida resources are based on the inferred resource estimates directly from the individual deposits studied plus any additional high and low-MgO resources in deposits not included in the study. ^Based on communications with James Cathcart of the U.S. Geological Survey. 19 -N- 5 I I I I 1^ 10 10 _1_ "T" 20 20 mi J 30 km PASCO SUMTER LAKE I 1_ POLK ORANGE OSCEOLA HILLSBOROUGH POLK HARDEE HIGHLANDS HARDEE DE SOTO CHARLOTTE GLADES FIGURE 9. - Area coverage in the Central Land-Pebble District (including the southern ex- tension), Florida. (Shaded area includes all demonstrated resources for this district consid- ered for this evaluation.) 20 quantities of magnesium oxide that are currently considered unacceptable (more than 1,0 pet). Research is underway to solve this problem by developing methods for benef iciating high-magnesium phos- phate to within acceptable limits (1.0 pet or lower). The Bureau of Mines re- search center in Tuscaloosa, Ala. , is working on this problem and has recently published a report dealing with this issue (8). Numerous phosphate compan- ies — including International Minerals and Chemical Corp. (IMC), W. R. Grace, Gar- dinier, and the TVA National Fertilizer Development Center — are also working to solve the magnesium oxide problem. Some of the processes being developed include the use of heavy-media separation tech- niques and improved flotation techniques to remove dolomite (which contains most of the magnesium oxide) from the phos- phate ore. Phosphate resources containing more than 1.0 pet magnesium oxide were not included (or costed) for the analysis. At the identified resource level, an estimated 2 billion tons or more of re- coverable phosphate rock exists in high- magnesium-oxide deposits in Florida with most of the tonnage classified as in- ferred. This estimate is very conserva- tive since most of these deposits have not been sufficiently drilled. High- magnesium-oxide resources are mainly in the counties of De Soto (approximately one-third of the total) and Hardee (approximately one-third), with the bal- ance in Manatee and other counties. The development of new technologies for pro- cessing high-magnesium-oxide phosphate will significantly increase Florida phos- phate reserves, although at an increased cost. It has been suggested that these new technologies would add between $3 and $6 per ton of product, although these figures are unconfirmed. The future resource potential for Flor- ida is almost entirely in the Hawthorn Formation (including the southern exten- sion and high-magnesium-oxide deposits). Figure 10 is an isopach map showing the thickness of the overburden overlying the Hawthorn Formation. Figure 11 shows the thicknesses of the formation itself, in- cluding the location of test cuttings from well holes used to evaluate the location and thickness of the formation and overlying sediments. These maps give clear indication of the vast extent of the Hawthorn Formation and its thickness, and the tremendous amounts of phosphate in Florida, particularly in the southern part of the State. Although at present much of this material is considered tech- nologically unminable or highly uneco- nomical to mine, this great resource potential does exist. TENNESSEE Like the rest of the domestic deposits evaluated, resources for Tennessee are at the demonstrated resource level and have been updated to January 1981. A total of 28.5 million tons of phosphate rock is potentially recoverable from a resource of 61.3 millin tons of phosphate ore, with most of this potential from produc- ing mines. The individual ore bodies in Tennessee are well defined; any undis- covered deposits of brown rock in the region would most likely be quite small. THE WEST The values for proposed or developing deposits in Idaho are based on resource information in the recent Caribou Na- tional Forest Phosphate Environmental Impact Statement (18); Bureau personnel developed the resource values and evalu- ated the explored deposits in Utah and Wyoming. The demonstrated resources of the Western United States as of January 1981 are listed in table 5. There are approximately 4.9 billion tons of phos- phate material in the western deposits evaluated for this study, containing about 2.5 billion tons of recoverable phosphated rock. In Idaho and Montana, where mining occurs in some of the higher grade rock, deposits contain just over 10 pet of all the potentially recoverable phosphate rock from the western area. Wyoming alone contains over half the potentially recoverable phosphate rock in the West. 21 TABLE 5. - Summary of Western U.S. demonstrated phosphate resources (Quantities in million metric tons; all grades weighted-average percent P2O5) State In situ ore tonnage In situ grade Recoverable rock product Rock product grade Idaho and Montana ^ 352 1,882 2,658 25.6 20.1 21.5 237 930 1,305 31.0 Utah 27.9 Wyoming 27.7 Total or weight-average 4,892 21.3 2,472 28.1 'Montana was included here to avoid disclosing individual company confidential data |50- Jacksonville > LEGEND Shaded area represents location of Hawthorn Formation Overburden contour, 50- ft interval 50 _i I 1 I I 100 1_ 150 m _l 200 km FIGURE 10. - Isopach map of the overburden overlying the Hawthorn Formation in Florida. (Modified from data supplied by IMC Corp.) O o 22 Jacksonville aoO' LEGEND Well site Structure contour, 200-ft interval o o "^00 50 I I 100 L_ 150 mi _J 200 km FIGURE n. by IMC Corp.) ^-^o^'.^ Isopach map of the Hawthorn Formation in Florida. (Modified from data supplied Not costed for this study is more than 1 billion additional tons of recoverable phosphate rock in these four States at the inferred resource level (most of which is of the unaltered type). In addition to these inferred resources are an estimated 10 billion tons of recover- able rock above adit-entry level at the hypothetical resource level and below adit-entry level as much as 100 billion tons to a depth of 2,000 m and ^ almost 300 billion more below 2,000 m (5). 23 DOMESTIC PHOSPHATE MINING AND BENEFICIATION METHODS Strip mining is the most common method of mining phosphate ore in Florida. In this operation, a dragline digs a series of parallel cuts and casts the overburden into previously mined cuts, A dragline then mines the exposed ore (matrix) and transfers it to an aboveground slurry pit from which it is pumped to the washer plant. An estimated 85 pet of the ore is physically recovered from the cut. In North Carolina and parts of Florida, dredges are used. In the Florida operation, a dredge excavates overburden and the spoil is pumped through pipelines to land reclamation areas behind the min- ing operation. Another dredge follows, and the exposed ore is removed and hy- draulically transported through pipelines and booster pumps to the washer plant (mill). In North Carolina only the upper portion of overburden is removed by a dredge. The ore and lower portions of overburden are removed by draglines. In dredging operations, the mine recoveries generally range from 80 to 90 pet. Slurried phosphate ore MINING AREA WASHER Ground water. WATER RESERVOIR Overflow Return water Pebble Clay waste Flotation feed FLOTATION STORAGE % Concentrated phosphate DRYING Sand tailings Clear decanted water WASTE STORAGE AREA SHIPPING WASTE STORAGE AREA FIGURE 12. - Typical process flowsheet, Southeastern United States. 24 An average sized phosphate mine in the Southeast treats about 9 million tons of ore per year, producing approximately 2 million tons of phosphate rock. In the Southeast, phosphate ore is beneficiated through a series of washing, sizing, and flotation circuits which separate phos- phate pellets from clay and quartz. The pebble portion of the ore is screened out during the washing stage. The processing stages of a typical southeastern phos- phate benef iciation plant are shown in figure 12. Phosphate recovery from these plants is typically 80 to 90 pet. The product from a plant of this type is phosphate rock suitable for phosphoric acid production. typically recovers 60 to 75 pet of the phosphate rock. The ore is slurried and then passes through a series of washers, scrubbers, screens, and cyclones to pro- duce a silt and sand-sized rock product. Nearly all the phosphate rock product from the washer plants is used as elec- tric furnace feed for production of ele- mental phosphorus, which is used in the chemical industry. The average phosphate operation in Tennessee (which includes production from a number of individual mines) has a capacity of approximately 1 million tons of ore treated per year, yielding 600,000 tons of phosphate rock. The Bureau of Mines, in conjunction with a Florida phosphate producer, is experimenting with the borehole mining method to recover the deep, untapped phosphate resources of Florida, par- ticularly in the northeastern part of the State. In this method, the deep phos- phate ore is mined through a borehole using a water-jet cutting system in which the ore is slurried and pumped to the surface. This method, although still in the research stage, could make available additional resources of phosphate rock. Tennessee phosphate ore is also mined with draglines, although the draglines used are much smaller than those used Florida. Draglines used in Tennessee must be small enough to remove the ore from narrow crevices and mobile enough to be moved easily and quickly from one mine site to another. In a typical operation, a bulldozer clears topsoil and removes the clay overburden. A dragline then removes the ore from a pit, typically attaining an 80-pct mining recovery; a bulldozer then backfills mined-out areas with spoil. The ore is transported by truck, or rail for longer hauls, to a field washer or a washer at the chemical plant. The basic benef iciation process in- cludes only a washer plant, which Open pit mining methods predominate in the Western U.S. phosphate mines, al- though there is one underground operation (Cominco American's Warm Springs mine at Garrison, Mont.). There are four produc- ing open pit mines in Idaho and one in Utah. In the open pit operations, top- soil, if present, is removed and stock- piled for later reclamation. Cherty overburden is drilled, blasted, and loaded by electric shovels into haulage trucks for placement into mined-out pits or on dumps. Waste shales, when stockpiled, are ripped or lightly blasted, then stripped by scrapers and push-dozers, with most of the waste going to stockpiles. The ore is mined by hydraulic shovels and hauled by trucks to a stockpile area for eventual benefici- ation. At the underground mine in Garri- son, Mont. , ore is extracted by a modi- fied room-and-pillar method with overhand open stopes. The average phosphate mine in the West treats around 1,3 million tons of ore per year. The average amount of product re- covered from a mine this size is just under 900,000 tons of phosphate rock. Most Western U,S, phosphate ore is ben- eficiated by crushing, washing, classify- ing, and then drying (fig, 13) , with a typical recovery of 65 to 85 pet; 25 WASTE ->- To waste dumps at mine site o is M 12: M 2 O M < M U H P4 !z: pq LOW-GRADE SHALES -1 ^ To stockpiles I at mine site I MEDIUM-GRADE ORE HIGH-GRADE ORE STOCKPILE CRUSHING 1/A in STOCKPILE CALCINING I i jj ELECTRIC FURNACE j t I FEED I J STOCKPILE CRUSHING - 1/A In WASHING CLASSIFYING - plus 325 mesh DRYING STOCKPILE GRINDING \ 1 CHEMICAL PLANT FEED Tailings (minus 325 mesh) to ponds at mill site FIGURE 13. - Typical process flowsheet. Western United States. 26 however, the Vernal Mine in Utah also uses flotation. The product is typically calcined to remove carbonaceous materials and then sent to a chemical plant. The four grade classifications for western phosphate rock are acid or fer- tilizer grade (+31 pet P2O5), also termed high grade; furnace grade (24 to 31 pet P2O5); benef iciation grade (18 to 24 pet P2O5), also termed medium grade; and low- grade shale (10 to 18 pet P2O5). Acid- grade rock is used as direct chemical plant feed; furnace-grade rock is used for electric furnace feed; benef iciation- grade rock is upgraded to either furnace or acid grade (most frequently to furnace grade) through the benef iciation stages shown on figure 13; and low-grade shales are stockpiled for possible future use. DOMESTIC PHOSPHATE COSTS Phosphate deposits in the Western United States were costed using various cost methodologies such as scaling tech- niques (from both current operations or models); the MAS Cost Estimating System (CES), a computerized version of the Bureau of Mines capital and operating cost manual (15); and actual reported company costs. Costs for producing mines and nonproducing deposits in Florida, North Carolina, and Tennessee are from cost models which Zellars-Williams , Inc., developed under contract (20) . The cost models are calibrated by confidential cost information from companies active in the phosphate industry. To protect the confidentiality of the cost data obtained, contributing operations were grouped into different cases according to size, age, reserve characteristics, and production cost criteria. A production cost for a "typical" mine representative of each case was calculated by averaging actual or estimated costs for the mines so grouped. These cost models were up- dated and modified by Bureau of Mines personnel for site-specific situations, such as matrix X, the number of drag- lines, pebble content, etc. The six cost models Zellars-Williams, Inc., developed for Florida, with costs updated to Janu- ary 1981 dollars, are presented in appendix B. Table 6 illustrates the average operat- ing costs used to develop the phosphate availability curves for U.S. phosphate mines and deposits. Mine and mill oper- ating costs in Florida are most affected by electrical power costs for the drag- lines and washer-flotation plants, labor, supplies, reagents, and drying oil. In the West, the greatest portion of operat- ing costs are the actual ore extraction costs (often contracted out) and the cost for calcining. As would be expected, underground mines in the West are much more expensive than surface mines. In Tennessee, the two most important parts of these costs are in ore haulage to the mills by truck and in the actual ore extraction (both costs are contained within the mine operating cost). Royalty costs for western deposits on Federal land were calculated as 5 pet of the estimated mine-mouth value. The State severance tax for phosphate in Idaho, Montana, North Carolina, Tennes- see, Utah, and Wyoming is either small or nonexistent. Idaho and Wyoming have a 2-pct severance tax based on the value after mining. Montana's 0.5-pct rate is also based on the value after mining. North Carolina, Tennessee, and Utah have no State severance tax for phosphate. Florida has a significant State severance tax; $1.84 per ton of rock product is the new rate, enacted for 1981. It is not based on the value after mining, as it had been in the past; rather, it is strictly the rate times the units recov- ered. Each year this rate will be up- dated based on producer-price indexes. The State severance tax is included in the column labeled "Other" on table 6, along with the property. State, and Fed- eral tax plus any royalty. These costs are greater for nonproducers because in most cases the overall total costs and revenues necessary to cover them are greater. 27 TABLE 6. - Operating costs for domestic phosphate operations (All costs are expressed as January 1981 dollars per metric ton of product on a weight-averaged basis) Average Transportation to Mine Mill Other 1 Total total cost (f.o.b. mill) plant or port2 Florida: Producers $9.20 $11.10 $2.60 $22.90 $27.80 $4.30 Nonproducers 10.00 14.10 7.60 31.70 46.00 5.00 North Carolina W W W W W W Tennessee: Producers 12.90 2.70 .40 16.00 17.30 1.40 Nonproducers W W W W W W Idaho: Producers 10.00 15.50 3.10 28.60 33.90 2.60 Nonproducers 18.90 15.50 2.30 36.70 43.60 2.40 Montana W W W W W W Utah: Producers W W W W W W Nonproducers: Surface 15.90 13.70 8.60 38.20 53.50 12.80 Underground. . . . 31.40 39.00 7.70 78.10 94.30 14.70 Wyoming: Nonproducers: Surface 21.70 12.40 6.70 40.80 58.80 8.50 Underground. . . . 46.90 28.30 15.30 90.50 125.30 10.60 W Withheld to avoid disclosing individual deposit confidential information. ^Includes all property, State, Federal, and severance taxes plus any royalty. ^Transportation to ports in Florida and to acid or elemental plants in the West (Idaho, Utah, Wyoming, and Montana) and Tennessee. These transportation costs pri- marily represent the cost of rail transport only. Although not included in the individual property analyses, transportation costs are also listed on table 6. In Florida these represent the rail costs to the ports of Tampa and Jacksonville. If the rock product is actually being sent to a nearby acid plant, the costs will most likely be less. In the West, costs shown on the table are the costs of transporta- tion to local acid or elemental plants. Since most of these plants are in Idaho, distances are shorter in that State than for deposits in Utah and Wyoming, which for the purposes of this study, send their rock to plants in Idaho. Table 7 shows the average capital costs estimated for this study to develop the nonproducing deposits in the United States at different ore capacities. These costs represent the costs to acquire, explore, develop, and equip a new mine site, along with the construc- tion of any necessary mine and mill plants and buildings. Costs associated with compliance with environmental regu- lations and permitting are included to the extent known. Environmental con- straints to development are discussed in appendix C. Capital costs for a new mine in Tennessee are not shown since there is 28 TABLE 7. - Estimated capital costs to develop nonproducing phosphate deposits in the United States Thousand metric tons Millions of January 1981 dollars Exploration, Mine Mill Total Cost per Cost per Ore per Product per acquisition. capi- capi- capi- annual annual year year and development tal tal tal ton ore ton product Southeast 2,500 450 9.6 8.9 21.3 39.8 15.90 88.40 5,600 1,000 32.2 16.1 38.3 86.6 15.50 86.60 15,600 2,400 74.6 34.5 71.4 180.5 11.60 75.20 West: Surface 1,100 800 3.7 10.2 58.7 72.6 66.00 90.80 Underground. 1,200 700 17.8 15.9 73.0 106.7 88.90 152.40 only one Tennessee nonproducing deposit in this evaluation and the costs would be considered confidential. In 1977 a developing operation in Tennessee that could produce approximately 1 million tons per year of product (from a number of small mines) would have cost approxi- mately $10 million for mine and washer facilities (2). I COMPARISON OF SOUTHEASTERN AND WESTERN RESOURCES As shown in the geology section, the in situ and feed grades in the West are con- siderably higher than those in the South- east. The western deposits start at over 20 pet P2O5 on the average, whereas the southeastern deposits average under 10 pet P2O5. Both areas upgrade to approxi- mately 30 pet P2O5 (slightly greater in the Southeast); i.e., more upgrading is necessary for the deposits in the South- east that for those in the West. Pro- cessing costs in the West, however, are equal to or greater than those in the Southeast because of calcining costs, which tend to be high because of their added energy requirements. Although mine recoveries in the West are slightly higher than those in the Southeast, and mill recoveries are very similar, total operating costs in the West are higher than those in the South- east, largely because of the operating costs. Mining greater in the West because amounts of overburden, the blasting required, and the of the operations nomies of scale). higher mine costs are of larger amount of smaller size (providing less eco- One of the more significant differences between the western and southeastern deposits is in transportation costs. Table 6 shows the costs to transport phosphate rock to ports in Florida and North Carolina (since these are the ports of departure for exports) and to local acid plants and elemental plants in the West and Tennessee (since virtually all of this material is consumed internally). In Florida transporting phosphate rock to the appropriate ports costs just over $4 per ton; transporting a ton of phosphate rock to local plants in Idaho costs about $2.50, and it could cost about $13.50 to ship rock from Utah to exist- ing plants in Idaho. If rock from Wyom- ing were sent to plants in Idaho, it would cost about $9.50 per ton. The transportation costs for deposits in Utah and Wyoming are high because most of the processing plants are presently in Idaho, which is the assumed desti- nation for their production. Quite likely, however, processing plants will be built in Utah and Wyoming if a large phosphate mining industry is established in those States. Once at the plants, the western rock must still be processed and 29 transported, thus Incurring additional costs before reaching a market. Since the major domestic rock and acid markets are in the East and Midwest, the south- eastern deposits clearly have a cost advantage over those in the West, The transport distances are shorter; barges can be used instead of rail, which would lower costs; and the access routes (mainly the Mississippi River) are more direct to the domestic agricultural mar- kets in addition to the export markets. Western phosphate, however, has a natural market in the agricultural industries of the Western States. The above factors provide a definite economic advantage to the southeastern deposits over the western deposits to supply most of the domestic and export markets. Southeastern deposits will not lose this advantage in the foreseeable future. As described in the resource section, over 60 pet of the demonstrated resources in the United States lie in the south- eastern deposits, although vast quanti- ties of phosphate in the West at the inferred and hypothetical levels repre- sent a significant future resource. AVAILABILITY OF DOMESTIC PHOSPHATE RESOURCES The potential tonnage and cost for each of the 130 mines and deposits evaluated have been aggregated onto phosphate rock availability curves, which illustrate the comparative costs associated with any given level of potential total output and provide an estimate of what the average phosphate rock price (in January 1981 dollars) would likely have to be for a given tonnage to be potentially avail- able. Costs reflect not only capital and operating costs, but also all Federal, State, and local taxes an operation in- curs selling phosphate rock f.o.b, mill. TOTAL AVAILABILITY Figure 15 shows the total availability of phosphate rock from Florida and North Carolina deposits, where nearly two- thirds of all evaluated resources occur. Nearly 4 billion tons of phosphate rock is potentially recoverable from Florida and North Carolina from demonstrated resources. At costs ranging up to $30 per ton, approximately 1 billion tons is potentially recoverable, 25 pet of the total from these two States and almost 85 pet of the total for the United States potentially available at a long-run price of $30. At $45, potentially available phosphate rock from Florida and North Carolina increases to 3 billion tons. Approximately 6.4 billion tons of phos- phate rock is potentially recoverable from all domestic deposits evaluated at the demonstrated resource level. As shown in figure 14, approximately 1.3 billion tons of phosphate rock is poten- tially recoverable at costs ranging up to $30 per ton, which is only 20 pet of the total recoverable tonnage. Approximately 2.4 billion additional tons of phosphate rock is potentially recoverable at costs ranging between $30 and $40 per ton. This means that at a long-run constant dollar price for phosphate rock of $45 per ton (approximately 1.5 times the Jan- uary 1981 price), 3.7 billion tons of phsophate rock is potentially available. Not shown on the curve are just over 700 million tons of phosphate rock costing over $100 per ton. Figure 16 shows the total availability of phosphate rock from the deposits in Idaho, Montana, Utah, and Wyoming. Nearly 2.5 billion tons of phosphate rock is potentially recoverable from these deposits, although many may have a pro- duction cost exceeding $100 per ton and are therefore not represented on the curve. Only 300 million tons is poten- tially available at $30 per ton, increas- ing 400 million tons at $45 per ton. Phosphate rock market prices vary sig- nificantly depending on the product grade. The three curves in figure 17 were developed for specific product-grade ranges. The product-grade ranges are less than 30.2 pet P2O5 (low grade), between 30.2 and 32 pet ^2^5 (medium grade) , and greater than 32 pet ^2^5 30 c o 0» E Q. JO "o T3 O O g ICX) 90 80 70 60- 50- 40 30 20 10 Costs are in January 1981 dollars and include a 15- pet rate ot return on investnnent ^ J. 1,000 2,000 3,000 4,000 5,000 6,000 TOTAL RECOVERABLE PHOSPHATE ROCK, million metric tons FIGURE 14. - Phosphate rock potentially recoverable fromall domestic deposits. 100 90 c o ■*— 80 o w E 70 ^. 0) CO Q. bU (O ^ O 50 o ■o 40 H to O 30 O -;! 20 P 10 —I 1 1 1 1 Costs are in January 1981 dollars and include a 15-pct rate ot return on investment ± ± 200 400 600 800 1,000 1,200 1,400 1,600 1,800 TOTAL RECOVERABLE PHOSPHATE ROCK, million metric tons FIGURE 16. - Phosphate rock potentially recoverable fromall western deposits. c o E a> Q. o o (/) O O _l P 100 90 T T High Low I H 'Medium r* ± Costs are in January 1981 dollars and include a 15-pct rate ot return on investment ± 400 800 1,200 1,600 2,000 2,400 2,800 3,200 3,600 TOTAL RECOVERABLE PHOSPHATE ROCK, million metric tons FIGURE 17. - Phosphate rock potentially recoverable from all domestic deposits, at selected grade ranges. 32 (high grade). The average prices for phosphate rock from domestic mines in 1981 are shown in table 8 (17). Of the total 6.4 billion tons of recoverable product evaluated in this study, approxi- mately 40 pet is from low-grade deposits, 50 pet from medium-grade deposits, and 10 pet from high-grade deposits. The curves show that at a long-run cost of $30 per ton, almost 100 million tons of low-grade rock, more than 1 billion tons of medium- grade rock, and over 100 million tons of high-grade rock are potentially avail- able. At $60 per ton, approximately 1 billion low-grade tons, 3 billion medium- grade tons, and 0.5 billion high-grade tons of rock are potentially available. Figure 18 shows the availability of phosphate rock from all domestic mines and deposits with separate curves for producers and nonproducers. The curve for producers shows that at costs ranging up to $30 per ton, almost 1.2 billion tons of phosphate rock is potentially recoverable, nearly three-quarters from Florida and North Carolina. At approxi- mately $40, total availability from these mines increases only to 1.3 billion tons, again nearly three-quarters from Florida and North Carolina. The curve for non- producers shows that at costs ranging up to $40 per ton, nearly 2 billion tons is potentially recoverable, increasing to 3 billion at $60. Five billion tons could TABLE 8. - 1981 phosphate rock prices (Dollars per metric ton, f.o.b. mine) Grade, pet P2O5 Plus 33.9 32.95 to 33.9 32 to 32.95 30.2 to 32 27.5 to 30.2 Minus 27.5 Average Plus 33.9 32.95 to 33.9 32 to 32.95 30.2 to 32 27.5 to 30.2 Minus 27.5 Average 32 to 32.95 30.2 to 32 27.5 to 30.2 Minus 27.5 Average 27.5 to 30.2 Minus 27.5 Average NAp Not applicable. Domestic Export Average United States $32.00 32.81 28.35 23.60 27.11 9.20 23.82 $45.54 37.93 34.36 31.75 28.15 NAp 33.93 $41.08 36.13 31.08 24.76 27.35 9.20 26.08 Florida and North Carolina — Land Pebble $32.00 32.81 25.26 23.57 31.66 14.71 25.17 $45.54 37.93 33.93 31.29 27.54 NAp 33.74 $41.08 36.13 29.14 24.61 30.55 14.71 27.17 Western States $35.94 24.25 10.46 9.26 18.06 $37.08 37.88 35.33 NAp 37.09 $37.15 27.42 14.93 9.26 21.98 Tennessee $15.93 8.75 12.01 NAp NAp NAp $15.93 8.75 12.01 33 c o E ex o o o u p 100 90 80 70 60- 50 40 30 10- I I I I I I Costs are in January 1981 dollars and include a 15-pct rate of return on investment Nonproducing depositsj .: Producing mines J. X ± 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 TOTAL RECOVERABLE PHOSPHATE ROCK, million metric tons FIGURE 18. - Phosphate. rock potentially recoverable from producing mines and nonproducing deposits. potentially be available from all nonpro- ducing deposits. Approximately 60 pet of the total potential tonnage from nonpro- ducing deposits is in Florida and North Carolina. POTENTIAL ANNUAL AVAILABILITY Another way of illustrating phosphate availability is to deisaggregate the total resource-availability curve and show potential production on an annual basis. For analysis, separate annual- availability curves have been constructed for producing and proposed operations. Potential annual production of phos- phate from producing operations is shown from 1981 through 2000. The curves for producing operations show the production capacity of existing mines, including planned expansions when known. It was assumed that all operations produce at full (100 pet) capacity over the life of the mine. Since no definite startup data is available for most of the nonproducers , it was assumed that preproduction began in a base year (N) of the analysis, which cannot be connected with an actual year since production from many of these deposits is not expected in the near future. However, the annual curves for nonproducers do show the required lead times before production can begin and therefore are important in that they show the potential annual production and asso- ciated costs of the mines of the future. In these curves, all nonproducers as- sumedly begin preproduction development at the same time; consequently the ton- nage available in a given year is likely overstated since not all the nonproducers will begin preproduction simultaneously. Figure 19 illustrates potential annual production from domestic producing mines. These mines are high-grade, low-cost operations, mostly located in the South- east. The analyses indicate that a 34 I u I E UJ § to O X Q. UJ -J CD < (T UJ > O o UJ 70 60 50 40 30 20 10- 1 1 I I 1 ; — I I Costs are in January 1981 dollars and include a 15-pctrate of return on investnrient \ \ \ . \ \ \ \ X ""$30 J. J. J. ± ± 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 YEAR FIGURE 19. - Potential annual availability of phosphate rock from producing mines. 1 maximum of 49 million tons of phosphate was potentially available in 1981 at $30 per ton and that 59 million tons was available at $42 per ton, compared with an actual 1981 production of 52.9 million tons ( 17) . Potential annual production from these mines (assuming full capacity) will begin to decline slowly until 1986, and then drop sharply as some mines be- come exhausted. However, because actual production since 1981 has been at less than full capacity, the decline of low- cost production will actually be delayed for several more years and will likely be more gradual than indicated on the curve. For production levels to be maintained, current capacities of the remaining mines may have to be expanded, and new lower grade deposits (some of which are already in developmental stages) will have to be brought on line. Figure 20 illustrates potential annual production for nonproducing deposits. At both cost ranges of up to $45 and $90 per ton, phosphate rock production would ini- tially increase dramatically as deposits came on line. From zero production in year N, output could rise in year N+4 to 50 million tons at costs ranging up to $45 per ton, and to 97 million tons at costs ranging up to $90 per ton. Production would peak in the year N+4 and remain relatively constant with a slight decline in annual production by the year N+18. Phosphate that could be produced for less than $30 per ton from nonproducers would peak at 7 million tons in the year N+3 and remain constant through the year N+18. This would indicate that most of the low-cost phosphate comes from currently producing mines, which is not surprising since the nonproducing deposits are usually of lower quality and will have higher costs. 35 c o 0) E c: o O o tr UJ X Q. CO O X a. UJ _j < UJ > O o UJ 120 100 80- 60- 40 20 Costs are in January 1981 dollars and include a 15-pctrate of return on investment N N+2 N+4 N+6 N+8 N+IO YEAR N+12 N+14 N+16 N+IB N+20 FIGURE 20. - Potential annual availability of phosphate rock from nonproducing deposits. CONCLUSIONS The agricultural industry is dependent upon the supply of fertilizers derived from phosphate rock. The adequacy of the future supply potential of phosphate rock from domestic sources has been disputed in recent years. In an attempt to assess domestic phosphate rock resources, the Bureau of Mines evaluated 130 domestic phosphate mines and deposits. The se- lected deposits included all resources of phosphate rock at the demonstrated level that met the criteria of this study and that can be mined and milled with current technology. Nearly 6.4 billion tons of phosphate rock is recoverable from domestic demon- strated resources. The southeastern deposits contain about 3.9 billion tons of recoverable phosphate rock, approxi- mately 60 pet of the total domestic re- source. The western deposits contain most of the remaining 2.5 billion tons of recoverable phosphate rock. The very small resources in Tennessee play only a minor role in the total domestic-resource picture. The 6.4 billion tons of demonstrated phosphate rock resources in the United States includes both low- and high-cost deposits. This study indicates that approximately 1.3 billion tons of phos- phate rock could be available at costs ranging up to $30 per ton, 3 billion tons at under $40 per ton, 3.6 billion tons at under $45 per ton, and 4.5 billion tons at under $60 per ton. The balance of recoverable resources comprises potential production from deposits that would cost from $60 to well over $100 per ton. These deposits would not likely be needed for many years, and their development is dependent upon future technological innovations. Of the total U.S. demonstrated phos- phate rock resource, only 20 pet is available from existing mines. At full- capacity levels, annual production from 36 the existing, low-cost phosphate opera- tions in the United States (particularly in Florida) will likely decline in the next decade. To maintain or increase these annual production levels, new de- posits will have to be developed from the remaining demonstrated resource, which accounts for approximately 80 pet of to- tal U.S. demonstrated resources. Based on the results of this study, and assum- ing current technology and product stan- dards, phosphate from these new opera- tions will be more expensive to produce than that from existing operations, re- quiring a price increase in real terms of about 50 pet above 1981 levels. In addition to its large demonstrated phosphate irock resource, the United States contains vast, untapped resources at the inferred and hypothetical levels. Although not individually evaluated in this study, these resources represent a significant future potential for the United States. It is estimated that some 7 billion tons of potentially recoverable phosphate rock exists at the inferred level (over 80 pet of which is in the Southeast), and over 24 billion tons of potentially recoverable phosphate rock exists at the hypothetical level (over 60 pet of which is also in the Southeast). New deposits will likely be discovered (particularly offshore deposits along the eastern seaboard) , low-grade material not included in this analysis could become economically minable, or technological advances could enable processing high- magnesium oxide material or mining deeper deposits. Each of these factors could greatly increase the amount of phosphate available and ensure a continued high level of future production from domestic resources. Of immediate interest is more than 2 billion tons of recoverable phosphate rock in Florida at the identified re- source level that has a high content of magnesium oxide and is presently con- sidered unnacceptable by the industry owing to the higher benef iciation costs of producing an acceptable acid plant feed. Given the progress several phos- phate companies and the Bureau of Mines have made in improving benef iciation technologies to lower the grade of mag- nesium oxide in the phosphate rock prod- uct, this additional 2 billion tons of rock will likely become available in the near future. The U.S. phosphate industry has been the world leader in the output of phos- phate rock and related products but is now facing the challenges of higher pro- duction costs and foreign competition for export markets (particularly from North Africa and the Middle East). Al- though the U.S. phosphate resource poten- tial is virtually unlimited, this study suggests that total production from phos- phate mines now in operation will decline during the next decade, and new lower grade, higher cost mines will have to be developed to satisfy demand for U.S. phosphate rock and related products into the next century. m REFEEIENCES 1. Arthur D. Little, Inc. Economic Impact of Environmental Regulations on the United States Copper Industry. Kept, to the U.S. Environmental Protection Agency, contract 68-01-2842; January 1978, reproduced and distributed by the Am. Min. Congr. , 1100 Ring Bldg. , Wash- ington, D.C. 2. Blue, T. A., and R. Portillo. CEH Marketing Research Report, Phosphate Rock. Chemical Economics Handbook — SRI International, March 1980. 3. Carter, R. A. An Integrated In- dustry — Phosphate Mining and Milling in Idaho. Min. Eng. , v. 30, N. 1, January 1978, pp. 29-36. 4. Cathcart, J. B. Phosphate in the Atlantic and Gulf Coastal Plains. Paper in Proc. 4th Forum on Geology of Indus- trial Minerals (Austin, Tex. , Mar. 14-15 1968), Bureau of Economic Geology, The University of Texas at Austin, December 1968, pp. 23-34. 37 5. Cathcart, J. B., R. P. Sheldon, and R. A. Gulbrandsen. Phosphate-Rock Re- sources of the United States. U.S. Geol. Survey Circ. 888, 1983. 6. Davidoff, R. L. Supply Analysis Model (SAM): A Minerals Availability System Methodology. BuMines IC 8820, 1980, 45 pp. 7. Gurr, T. M. , Geology of U.S. Phos- phate Deposits. Min. Eng. , v. 31, No. 6, June 1979, pp. 682-691. 8. Llewellyn, T. 0., B. E. Davis, G. V. Sullivan, and J. P. Hansen. Bene- ficiation of High-Magnesium Phosphate From Southern Florida, BuMines RI 8609, 1982, 16 pp. Fossil Fuels in the United States and Canada (contract JO225026) . OFR 10-78, December 1977, 382 pp.; also available as Clement, G. K. , Jr., R. L. Miller, P. A. Seibert, L. Avery, and H. Bennett, Capi- tal and Operating Cost Estimating System Manual for Mining and Benef iciation of Metallic and Nonmetallic Minerals Except Fossil Fuels in the United States and Canada. BuMines Spec. Pub. 4-81, 1981, 149 pp. 16. U.S. Bureau of Mines. Phosphate Rock. Mineral Commodity Summaries 1982, January 1982, pp. 112-113, 17, , Marketable Phosphate Rock- February 1982, Mineral Industry Surveys, Apr. 14, 1982, 5 pp. 9. Opyrchal, A. M. , and K. L. Wang. Economic Significance of the Flor- ida Phosphate Industry: An Input-Output (I-O) Analysis. BuMines IC 8850, 1981, 62 pp. 18, U,S, Department of the Interior and U,S, Department of Agriculture, Development of Phosphate Resources in the Southeastern Idaho, Final Environmental Impact Statement, v, 1, 1977, p, 1-3, 10. Service, A. L. , and C. C. Popoff. An Evaluation of the Western Phosphate Industry and Its Resources (in Five Parts). 1. Introductory Review. Bu- Mines RI 6485, 1964, 86 pp. 11. Smith, L. Armand Hammer and the Phosphate Puzzle. Fortune Magazine, Apr. 7, 1980, pp. 48-51. 12. Stermole, F. J. Economic Evalua- tion and Investment Decision Methods. Investment Evaluations Corp. , Golden, Colo. , 1974, 449 pp. 13. Stowasser, M. F. Phosphate Rock. BuMines Minerals Yearbook 1980, v. 1, pp. 619-637. 14. Phosphate Rock. Ch. in Mineral Facts and Problems, 1980 Edition. BuMines B 671, 1981, pp. 663-682. 19. U.S. Geological Survey. Princi- ples of a Resource/Reserve Classification for Minerals. U.S. Geol. Survey Circ. 831, 1980, 5 pp. 20. Zellars-Williams , Inc. Evaluation of the Phosphate Deposits of Florida Us- ing the Minerals Availability System (contract J0377000). BuMines OFR 112-78, June 1978, 199 pp.; NTIS PB 286 648/ AS. 21. . Evaluation of Phosphate Deposits of Georgia, North Carolina, and South Carolina Using the Minerals Avail- ability System (contract JO377000). Bu- Mines OFR 14-79, September 1978, 65 pp. 22. . Evaluation of the Phos- phate Deposits of Tennessee Using the Minerals Availability System (contract J0377000). BuMines OFR 13-79, September 1978, 37 pp. 15. STRAAM Engineers, Inc. Capital and Operating Cost Estimating System Handbook — Mining and Benef iciation of Metallic and Nonmetallic Minerals Except 23. Phosphate Rock End-Use Their Costs (contract Products and J077000). BuMines OFR 102-79, July 1978, 73 pp. 38 APPENDIX A. —DOMESTIC PHOSPHATE DEPOSIT STATUS AND OWNERSHIP Property name Property status Owner FLORIDA Acref oot Johnson Big Four Bonny Lake Mine Boyette and Fishawk. Brooker-Dukes C.F. Hardee Phosphate Complex Christina Reserve Clear Springs Cooks Hammock #1 Cooks Hammock #2 David C. Turner Heirs Deep Creek Deseret Ranch Desoto-Manatee Reserve Duette Mine Durrance-Waters Tract Farmland Hardee Mine Farmland Hillsborough Reserve First Mississippi Chemical Tract... Fort Green Mine. Fort Meade Mine #1 Fort Meade Mine #2 Four Corners Fridovich Hard Rock Deposit Hard Rock Colloidal Clay Hardee Mine Hardee West Prospect Hardrock Deposit Haynesworth Mine Hillsborough Co. -Farmland Brewster. Hookers Prairie Hopewell Mine Hunt Brothers Ranch Keys Property Kingsf ord Mine La Crosse Deposit Little Payne Creek Lonesome Mine. Manatee North Manatee South Manson- Jenkins Mobil Area N.E. Manatee Swift-Grace Nichols Mine No . Columbia County #2 Noralyn-Phosphoria North Lake City Deposit Northeast Manatee-Texaco Osceola National Forest Payne Creek-Palmetto Pierce-Pebbledale Pine Level Deposit Polk County Mine Rockland Mine. Rutland-Corvin-Vale. . . . Saddle Creek-Ebersbach. Silver City Mine South Fort Meade South Hardee Stanaland Ranch Suwannee River Mine.... Swift Creek Mine Swif t-Durrance Area..., Texaco Manatee Waters Tract Watson Mine Explored. Producer. do.. Explored. , do Producer. . . Explored. . , Producer. . , Explored. . , do do do do Developing. do Explored. . . Developing. Explored. . . do Producer. . . do do Developing. Explored. . . do Producer. . . Explored. . . do do Producer. . . Explored. . . Producer. . . Developing. Explored. . . do Producer. . . Explored. . . do Producer. . . Explored. . . do do do.. do.. Producer. Explored. Producer. Explored. do.. do.. Producer. Explored. do.. Producer. do.. Explored. . . Producer. . . Producer. . . Developing. Explored. . . do Producer. . . do Explored. do.. do.. Producer. Freeport Phosphate Mining Co..... AMAX Inc W.R. Grace Co ^grico Chemical Co , Kerr-McGee Chemical Corp ., C.F. Industries Inc Mobil Chemical Co IMC Corp Monsanto Co Unidentified major paper company. Heirs of D.C. Turner Occidental Chemical Co Mormon Church AMAX Inc ESTECH U.S.S. Agri-Chemicals Farmland Industries Inc do First Mississippi Chemical Corp., Agrico Chemical Co Mobil Chemical Co Gardinier Inc W.R. Grace Co Agri-Leis Corp T/A Minerals , Anco-Kellog-Howard-Loncala-Sun. . , First Mississippi Chemical Corp., Various ownerships .do. Brewster-American Cyanamid-Kerr-McGee. Pruitt-Thompson-Jameson-Simms W.R. Grace Co Noranda Mines Ltd IMC Corp .do. • do. Kerr-McGee Chemical Corp USS Agri-Chem-Gardinier-others Brewster Phosphates and American Cyanamld. W.R. Grace Co • do. Type of operation U.S.S. Agri-Chemicals Various ownerships W.R. Grace Co. and others Mobil Chemical Co Southern Resin Corp IMC Corp Kerr-McGee Chemical Corp Various ownerships U.S. Forest Service Agrico Chemical Co do AMAX Inc T/A Minerals U.S.S. Agri-Chemicals and Freeport Phosphate Co. IMC Corp Agrico Chemical Co ESTECH Mobil Chemical Co. and others Gardinier Inc. IMC Corp Occidental Chemical Co do Various ownerships..., Texaco Inc U.S.S. Agri-Chemicals. ESTECH Surface. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. 1 39 Property name Property status Owner Type of operation FLORIDA — Continued Wingate Creek Mine Zolfo Springs Area Small Ownerships Zolf o-Stauf f er Developing. Explored. . . do Beker Industries Various ownerships... Stauffer Chemical Co. Surface. Do. Do. IDAHO Champlease-Mountain Fuel-Husky #1. Conda Mine and Smokey Canyon Diamond Creek , Gay Mine-Dry Valley Henry Mine .• Maybe Canyon Mine N . Henry-Trail-Caldwell-Blackf oot . Wooley Valley-Rasmus sen Ridge Developing. Producer. . . Explored. . . Producer. . . do do Developing. Producer. . . Beker Industries J.R. Simplot Co Alumet Corp J. R. Simplot Co. and FMC Corp Monsanto Co Beker-Western Fertilizer Consortium (Conda Partnership) . Monsanto Co Stauffer Chemical Co Surface. Do. Do. Do. Do. Do. Do. Do. MONTANA Warm Springs Creek | Producer | Cominco American Inc. | Underground. NORTH CAROLINA Lee Creek Mine North Carolina Phosphate. Producer. . . Developing. Texas Gulf Chemical Corp North Carolina Phosphate Corp. Surface. Do. TENNESSEE Hickman and Maury Co. properties... Hooker Chemical properties Monsanto properties Stauffer Chemical Co. property Tennessee Valley Authority Reserves Producer do do do Past producer M.C. West Inc Hooker Chemical Co Monsanto Co Stauffer Chemical Co. and others. Tennessee Valley Authority Surface, Do. Do. Do. Do. UTAH Central Wasatch Range #1. Central Wasatch Range #2. Crawford Mountains //I.... Crawford Mountains #2.... Crawford Mountains §3.... Crawford Mountains #A.... Crawford Mountains #5.... Flaming Gorge #1 Flaming Gorge #2 Flaming Gorge #3 Northern Wasatch Range... Vernal Field #1 Vernal Field #2 Vernal Field #3 Vernal Field #4 Vernal Field #5 Vernal Mine Explored. do.. do.. do.. .do. .do. .do. .do. .do. .do. do.. do.. Explored. do.. do.. do.. Producer. Public land, unleased. do Stauffer Chemical Co, do do .do, .do. Public land, unleased. do do do U.S. Steel. do do do. do. Chevron. Surface. Underground. Surface. Do. Underground. Do. Do. Surface. Underground. Do. Surface. Do. Do. Underground. Do. Do. Surface. WYOMING Gros Ventre Range #1 Gros Ventre Range #2 Hoback Range #1 Hoback Range #2 Hoback Range #3 S.E. Wind River Range #1. S.E. Wind River Range #2. Salt River Range #1 Salt River Range #2 Salt River Range #3 Snake River #1 Snake River #2 Snake River Snake River //3. #5. Snake River South Ridges #1. . . South Ridges #2. . . South Ridges #3. . . Sublette Range #1. Sublette Range #2. TUN? #1 TUNP #2 TUNP //3 TUNP #4 Wyoming Range #1., Wyoming Range #2.. Explored. do.. do.. .do. .do. .do. do do Explored do do .do., .do., .do.. .do .do .do do Past producer Explored do do do .do. .do. .do. Public land, unleased. do .do. .do. .do. .do. .do. .do. .do. .do. .do. .do. .do. .do. .do, .do, .do. .do, .do, .do, .do, .do. .do. .do. .do. .do. Surface. Underground. Surface. Do. Underground. Surface. Underground. Surface. ' Underground. Do. Surface. Underground. Surface. Underground. Do. Surface. Underground. Do. Surface. Underground. Surface. Do. Underground. Do. Surface. Underground. 40 APPENDIX B.~THE ZELLARS-WILLIAMS COST MODEL FOR FLORIDA PHOSPHATE—DESCRIPTION OF TYPICAL CASES The following are descriptions of the six Zellars-Williams , Inc., cost models for Florida phosphate deposits. The descriptions and following discussions are taken almost entirely from the Zellars-Williams final report entitled "Evaluation of the Phosphate Deposits of Florida Using the Minerals Availability System" (20). Case I Large mine (2,750,000 to 4,500,000 tons of product per year). Low matrix X in the 2.8- to 3.5-yard- per-ton range. High pebble-to-concentrate ratio (that is, pebble ranging from 40 to 50 pet of the total product). Average product above 32 pet P2O5. Mine at least 10 years old. Case II Medium-sized mine (1,360,000 to 2,750,000 tons of product per year). Reserve characteristics same as case I, Mine at least 10 years old. Case IIA Medium-sized mine (1,360,000 to 2,750,000 tons of product per year). Reserve characteristics same as case I. Mine not more than 2 years old. Case III Small mine (900,000 to 1,360,000 tons of product per year). Case IV Large mine (2,750,000+ tons of product per year) . High matrix X in the 3.8- to 4.5-yard- per-ton range. Low pebble-to-concentrate ratio (that is, pebble ranging from 10 to 20 pet of the total product). Lower P2O5 grade (30.7 to 31.1 pet P2O5) with higher MgO content. Case V Small mine (900,000 to 1,800,000 tons of product per year) . Reserve characteristics similar to case IV. Cases I, II, IIA, and III represent existing mines with high-grade reserves typical of the active mining area in cen- tral Florida. Cases IV and V represent new or proposed mines with low-grade re- serves typical of the areas iimnediately to the south, but applicable to other areas in the State. Table B-1 summarizes production cost data developed for the six cases, and tables B-2 through B-13 provide a more detailed itemization of costs. Factors Affecting Production Costs The detailed study of production cost data for existing and proposed mines led to identifying the key factors affecting production costs. The two variables found to have the greatest influence on production costs were (1) matrix X (recoverable product per unit volume of ore) and (2) mine size (production rate) . Reserve characteristics same as case I. 41 TABLE B-1. - Mining and milling production cost summary Dollars per ton of product (dry, f.o.b. mill) Case I Case II Case IIA Case III Case IV Case V Direct cost. .............. 12.91 .80 1.46 13.91 1.01 1.46 13.53 .86 1.46 16.14 1.31 1.46 15.41 .78 1.85 16.38 Indirect cost. ............ 1.26 Fixed cos t 1.85 Total 15.17 16.38 15.85 18.91 18.04 19.49 TABLE B-2. - Production cost of typical large mine in higher quality ore (case I) Total operating cost per ton of product (dry, f.o.b.) Cost summary by category Cost per ton of ore (dry, f.o.b. mill) Mine Mill Total Raw materials, utilities, and support: Power , Reagents , Fuel (gasoline and diesel) , Fuel (fuel oil drying)! , Supplies , Mobile mine-support equipment.. , Outside services (dam construction and reclamation) , Direct labor: Operating , Supervisory , Plant maintenance: Labor , Supervision , Maintenance parts and supplies , Replacement mine pipe , Payroll overhead (fringes, etc.) , Subtotal direct costs...... , Administrative, technical, clerical labor. Payroll overhead (administrative) Facilities maintenance and supplies General overhead (including head office, charges, exploration, and research) Subtotal indirect costs Total direct and indirect costs, Local taxes, Insurance. . , Subtotal fixed costs, Grand total cost...., $3.10 1.19 .04 2.58 .35 .14 .78 1.46 .40 .50 .25 1.32 .21 .59 12.91 .45 .12 .07 .16 .80 13.71 1.40 .06 1.46 15.17 $0.31 .01 .07 .03 .19 .20 .06 .06 .03 .16 .05 .08 $0.46 .29 .64 .02 .16 .04 .06 .03 .17 ) .07 1.25 1.94 .06 .01 .01 .02 .06 .01 .01 .02 ,10 10 1.35 2.04 .29 ,01 .05 .01 .30 .06 1.65 2.10 $0.77 .29 .01 .64 .09 .03 .19 .36 .10 .12 .06 .33 .05 .15 3.19 .12 .02 .02 .04 .20 3.39 .34 .02 .36 3.75 ^Rock may or may not be dried in all cases since phosphoric acid processes are now available for the use of wet rock. Cost presented is for dry rock. 42 TABLE B-3. - Production cost of typical medium-sized mine in higher quality ore (case II) Total operating cost per ton of product (dry, f.o.b») Cost summary by category Cost per ton of ore (dry, f.o.b. mill) Mine Mill Total Raw materials, utilities, and support: Power Reagents Fuel (gasoline and diesel) Fuel (fuel oil drying)' Supplies , Mobile mine-support equipment , Outside services (dam construction and reclamation) Direct labor: Operating Supervisory , Plant maintenance: Labor Supervision Maintenance parts and supplies Replacement mine pipe Payroll overhead (fringes, etc.) Subtotal direct costs Administrative, technical, clerical labor. Payroll overhead (administrative) Facilities maintenance and supplies General overhead (including head office, charges, exploration, and research) Subtotal indirect costs Total direct and indirect costs, Local taxes, Insurance. . . Subtotal fixed costs, Grand total cost..... $2.40 1.51 .06 2.58 .36 .21 .63 1.80 .53 .63 .33 1.89 .22 .76 13.91 .63 .16 .07 .15 1.01 14.92 1.40 .06 1.46 16.38 $0.24 .02 .07 .05 .16 .25 .08 .08 .04 .24 .06 .11 $0.36 .38 .65 .02 .20 .05 .08 .04 .24 I .09 1.40 2.11 .08 .02 .01 .02 .08 .02 .01 .02 13 .13 1.53 2.24 .30 .01 .05 .01 .31 .06 1.84 2.30 $0.60 .38 .02 .65 .09 .05 .16 .45 .13 .16 .08 .48 .06 .20 3.51 .16 .04 .02 .04 .26 3.77 .35 .02 .37 4.14 'Rock may or may not be dried in all cases since phosphoric acid processes available for the use of wet rock. Cost presented is for dry rock. are now 43 TABLE B-4. - Production cost of typical medium-sized mine in higher quality ore (case IIA) Cost summary by category Total operating cost per ton of product (dry, f.o.b.) Cost per ton of ore (dry, f.o.b. mill) Mine Mill Total Raw materials, utilities, and support: Power Reagents Fuel (gasoline and diesel) Fuel (fuel oil drying)! , Supplies Mobile mine-support equipment. Outside services (dam construction and reclamation) , Direct labor: Operating , Supervisory , Plant maintenance: Labor , Supervision , Maintenance parts and supplies , Replacement mine pipe , Payroll overhead (fringes, etc.) , Subtotal direct costs , Administrative, technical, clerical labor. Payroll overhead (administrative) Facilities maintenance and supplies General overhead (including head office, charges, exploration, and research) Subtotal indirect costs Total direct and indirect costs, Local taxes, Insurance. . , Subtotal fixed costs. Grand total cost...., $2.80 1.97 .05 2.58 .32 .16 .59 1.54 .43 .53 .27 1.47 .18 .64 13.53 .51 .13 .07 .15 .86 14.39 1.40 .06 1.46 15.85 $0.34 .02 .07 .05 .18 .25 .08 .08 .04 .22 .06 .11 $0.51 .59 .77 .02 1.50 .08 .02 .01 .02 .13 1.63 .36 .01 .37 2.00 .21 .05 .08 .04 .22 ) .09 2.58 .08 .02 .01 .02 .13 2.71 .06 .01 .07 2.78 $0.85 .59 .02 .77 .09 .05 .18 .46 .13 .16 .08 .44 .06 .20 4.08 .16 .04 .02 .04 .26 4.34 .42 .02 .44 4.78 'Rock may or may not be dried in all cases since phosphoric acid processes are now available for the use of wet rock. Cost presented is for dry rock. 44 TABLE B-5. - Production cost of typical small mine in higher quality ore (case III) Cost summary by category Total operating cost per ton of product (dry, f.o.b.) Cost per ton of ore (dry, f.o.b. mill) Mine Mill Total Raw materials, utilities, and support: Power $2.56 1.77 .08 2.58 .46 .26 .70 2.31 .70 .76 .41 2.11 .47 .97 $0.29 .02 .10 .07 .20 .36 .12 .11 .06 .30 .13 .15 $0.43 .50 .73 .03 .29 .08 .11 .06 .30 .12 $0.72 -50 Reagents Fuel (gasoline and diesel) Fuel (fuel oil drying)! Supplies ................................ .02 .73 .13 Mobile mine-support equipment Outside services (dam construction and reclamation) .07 .20 Direct labor: Operating .65 Supervisory ............................. .20 Plant maintenance: .22 Supervision .12 .60 Replacement mine pipe. .................. .13 Payroll overhead (fringes, etc.) .27 Subtotal direct costs 16.14 1.91 2.65 4.56 Administrative, technical, clerical labor. .83 .20 .10 .18 .12 .03 .01 .03 .12 .03 .01 .03 .24 .06 Facilities maintenance and supplies General overhead (including head office, charges, exploration, and research) .02 .06 Subtotal indirect costs. ............. 1.31 .19 .19 .38 17.45 2.10 2.84 4.94 Local taxes ............................... 1.40 .06 .34 .01 .06 .01 .40 Insurance ................................. .02 Subtotal fixed costs 1.46 .35 .07 .42 Grand total cost 18.91 2.45 2.91 5.36 'Rock may or may not be dried in all cases since phosphoric acid processes are now available for the use of wet rock. Cost presented is for dry rock. 45 TABLE B-6. - Production cost of typical large mine in lower quality ore (case IV) Cost summary by category Total operating cost per ton of product (dry, f.o.b.) Cost per ton of ore (dry, f.o.b. mill) Mine Mill Total Raw materials, utilities, and support: Power , Reagents , Fuel (gasoline and diesel) , Fuel (fuel oil drying) ' , Supplies , Mobile mine-support equipment , Outside services (dam construction and reclamation) , Direct labor: Operating Supervisory , Plant maintenance: Labor , Supervision Maintenance parts and supplies Replacement mine pipe Payroll overhead (fringes, etc.) , Subtotal direct costs , Administrative, technical, clerical labor. Payroll overhead (administrative) Facilities maintenance and supplies General overhead (including head office, charges, exploration, and research) Subtotal indirect costs Total direct and indirect costs. Local taxes, Insurance, , . Subtotal fixed costs, Grand total cost...., $4.02 2.89 .05 2.58 .32 .15 .59 1.48 .40 .51 .25 1.37 .19 .61 15.41 .48 .12 .06 .12 .78 16.19 1.79 .06 1.85 18.04 $0.26 .01 .04 .02 .10 .13 .04 .04 .04 .11 .03 .06 $0.39 .47 .42 .01 .11 .03 .04 .02 .11 ) .04 ,88 1,64 ,04 ,01 ,01 ,01 ,04 .01 .01 .07 .06 .95 1.70 .25 .01 .04 ,26 ,04 1,21 1.74 $0.65 .47 .01 .42 .05 .02 .10 .24 .07 .08 .06 .22 .03 .10 2.52 .08 .02 .01 .02 ,13 2,65 .29 .01 .30 2.95 iRock may or may not be dried in all cases since phosphoric acid processes are now available for the use of wet rock. Cost presented is for dry rock. 46 TABLE B-7. - Production cost of typical small mine in lower quality ore (case V) Cost summary by category Total operating cost per ton of product (dry, f.o.b.) Cost per ton of ore (dry, f.o.b. mill) Mine Mill Total Raw materials, utilities, and support: Power , Reagents Fuel (gasoline and diesel) , Fuel (fuel oil drying) 1 , Supplies c Mobile mine-support equipment , Outside services (dam construction and reclamation) , Direct labor: Operating , Supervisory , Plant maintenance: Labor , Supervision , Maintenance parts and supplies , Replacement mine pipe , Payroll overhead (fringes, etc.) , Subtotal direct costs , Administrative, technical, clerical labor. Payroll overhead (administrative) Facilities maintenance and supplies General overhead (including head office, charges, exploration, and research) Subtotal indirect costs Total direct and indirect costs, Local taxes, Insurance. . Subtotal fixed costs, $2.82 2.02 .08 2.58 .42 .26 .81 2.15 .67 .75 .40 2.28 .22 .92 16.38 .78 .19 .09 .20 1.26 17.64 1.79 .06 1.85 $0.24 .02 .07 .06 .17 .26 .09 .08 .04 .25 .05 .11 1.44 .08 .02 .01 .02 .13 1.57 .33 .01 ,34 $0.37 .44 .56 .02 .21 .06 .08 .04 .36 I .09 2.23 .08 .02 .01 .02 13 2.36 ,06 ,01 ,07 $0.61 .44 .02 .56 .09 .06 .17 .47 .15 .16 .08 .61 .05 .20 3.67 .16 .04 .02 .04 .26 3.93 .39 .02 .41 Grand total cost | 19.49 | 1.91 | 2.43 | 4.34 'Rock may or may not be dried in all cases since phosphoric acid processes are now available for the use of wet rock. Cost presented is for dry rock. Generally, the more ore that must be processed to yield a ton of product, the higher the production cost. Tables B-2 through B-7 show that the production cost for cases I through III, representing the lower matrix X ore bodies, is substan- tially lower than that for mines with higher matrix X ore (cases IV and V, tables B-6 and B-7). Other ore and min- ing factors that influence production costs are listed and briefly discussed below: Total X . - Total X refers to the total yards of overburden plus ore that must be handled to produce a dry ton of product. Since draglines can move overburden very inexpensively, total X generally has a minor effect on production costs if the overburden is reasonably stable. If the 47 overburden is sufficiently thick, larger Matrix Clay Content . - The clay content draglines may be required that increase of the ore is significant because in- both capital and production costs. creased clay demands more extensive waste disposal and often affects the attrition- Concentrate-to-Pebble Ratio . - Because ability of the ore. Tough, heavy clays pebble is less expensive to produce than can slow pumping rates, reduce pro- concentrate, ore containing pebble is duction, and contaminate benef iciation usually associated with a lower produc- products, tion cost and better product recovery, TABLE B-8. - Operating parameters for average mine (case I) (3.10 million tons of product per year; 12.76 million tons of ore per year) Production: Pebble million tons. . 1.77 Total concentrate do 1.33 Pebble-concentrate ratio 1.33 Total production million tons. . 3. 10 Mining data: Matrix depth ft.. 11.9 Overburden depth ft. . 26.7 Total depth ft. . 38.6 Matrix density Ib/f t3. , 88.5 Matrix Xl yd^/ton product.. 3.4 Total X2 do 11.1 Tons of matrix per ton of product^ 4.11 Matrix, average pumping distance mi. . 2.92 Slimes in matrix pet. . 28 Slimes per year tons or acre ft.. 9,880 Tailing million tons/yr. . 6.748 Tailings, average pumping distance mi.. 2.85 Operating time hr/yr. . 8,760 Number of operating days per year 365 Acres mined per year 610 Equipment data: Number of draglines 2 Size of draglines yd3.. 45 Number of pumping systems 2 Number of washer trains 2 Number of flotation plant trains 2 Number of dryers 1 Mine Mill Operating personnel: Operating labor 75 61 Direct production supervision 25 17 Maintenance labor 22 20 Maintenance supervision 12 12 Technical 15 14 General administrative 12 12 Total 161 136 ^Matrix X = yd^ of ore that must be processed to yield a ton of product. ^Total X = yd^ of overburden plus ore that must be handled or processed to yield a ton of product. ^(Matrix X) (density or tons/yd^) = tons of matrix/ton of product. 48 TABLE B-9. - Operating parameters for average mine (case II) (1.95 million tons of product per year; 7.80 million tons of ore per year) Production: Pebble million tons. . 1.10 Total concentrate do .85 Pebble-concentrate ratio 1.29 Total production million tons. . 1.95 Mining data: Matrix depth ft. . 16.2 Overburden depth f t. . 28. 1 Total depth ft. . 44.3 Matrix density Ib/f t3. , 92.6 Matrix X' yd^/ton product.. 3.2 Total X2 do 8.7 Tons of matrix per ton of product3 4.00 Matrix, average pumping distance mi.. 1.94 Slimes in matrix' pet.. 35.0 Slimes per year tons or acre ft.. 7,959 Tailing million tons/yr. . 3.22 Tailings, average pumping distance mi.. 2.0 Operating time hr/yr. . 8,760 Number of operating days per year 365 Acres mined per year 263 Equipment data: Number of draglines 2 Size of draglines yd^,. 45 Number of pumping systems 2 Number of washer trains 2 Number of flotation plant trains 2 Number of dryers 1 Mine Mill Operating personnel: Operating labor 65 59 Direct production supervision 23 16 Maintenance labor 20 19 Maintenance supervision 11 11 Technical 14 13 General administrative 12 11 Total 145 129 'Matrix X = yd^ of ore that must be processed to yield a ton of product. ^Total X = yd^ of overburden plus ore that must be handled or processed to yield a ton of product. ^(Matrix X) (density or tons/yd^) = tons of matrix/ton of product. 49 TABLE B-10. - Operating parameters for average mine (case IIA) (2.54 million tons of product per year; 8.58 million tons of ore per year) Production: Pebble million tons. . 1.16 Total concentrate do 1.38 Pebble-concentrate ratio .85 Total production million tons. . 2.54 Mining data: Matrix depth ft. . 13.0 Overburden depth ft.. 26.4 Total depth ft. . 39.5 Matrix density Ib/f t3. . 88.0 Matrix X^ yd^/ton product.. 2.8 Total X2 do 8.6 Tons of matrix per ton of product^ 3.38 Matrix, average pumping distance mi.. 2.1 Slimes in matrix pet.. 27.0 Slimes per year tons or acre ft.. 6,170 Tailing million tons/yr . . 6 ,076 Tailings, average pumping distance ml.. 2.0 Operating time hr/yr. . 8,760 Number of operating days per year 365 Acres mined per year 380 Equipment data: Number of draglines 2 Size of draglines yd^.. 45 Number of pumping systems 2 Number of washer trains 2 Number of flotation plant trains 2 Number of dryers 1 Mine Mill Operating personnel: Operating labor 65 59 Direct production supervision 23 16 Maintenance labor 20 19 Maintenance supervision 11 11 Technical 14 13 General administrative 12 11 Total 145 129 'Matrix X = yd^ of ore that must be processed to yield a ton of product. ^Total X = yd^ of overburden plus ore that must be handled or processed to yield a ton of product. ^(Matrix X) (density or tons/yd^) = tons of matrix/ton of product. 50 TABLE B-11. - Operating parameters for average mine (case III) (1.12 million tons of product per year; 4.02 million tons of ore per year) I Production: Pebble million tons. . 0.34 Total concentrate do .58 Pebble-concentrate ratio .97 Total production million tons.. 1.12 Mining data: Matrix depth ft. . 14.6 Overburden depth .ft. . 20.0 Total depth ft. . 34.6 Matrix density Ib/f t3. . 90.0 Matrix X^ yd^/ton product.. 2.9 Total X2 do 7.1 Tons of matrix per ton of product 3.60 Matrix, average pumping distance^ mi.. 4.59 Slimes in matrix pet. . 39 Slimes per year tons or acre ft.. 4,098 Tailing million tons/yr. . 2. 290 Tailings, average pumping distance mi.. 2.5 Operating time hr/yr. . 8,760 Number of operating days per year 365 Acres mined per year 156 Equipment data: Number of draglines 1 Size of draglines yd^.. 45 Number of pumping systems 1 Number of washer trains 1 Number of flotation plant trains 1 Number of dryers 1 Mine Mill Operating personnel: Operating labor 41 30 Direct production supervision. 16 11 Maintenance labor 14 13 Maintenance supervision 8 7 Technical 11 10 General administrative 8 8 Total 98 99 ^Matrix X = yd^ of ore that must be processed to yield a ton of product. ^Total X = yd^ of overburden plus ore that must be handled or processed to yield a ton of product. ^(Matrix X) (density or tons/yd^) = tons of matrix/ton of product. 51 TABLE B-12, - Operating parameters for average mine (case IV) {2,12 million tons of product per year; 16.63 million tons of ore per year) Production: Pebble million tons. . 0.54 Total concentrate do 2.18 Pebble-concentrate ratio .25 Total production million tons . . 2.72 Mining data: Matrix depth ft. . 34.2 Overburden depth f t. . 31.6 Total depth ft. . 65.8 Matrix density Ib/f t3. . 92.5 Matrix X' yd^/ton product.. 4.9 Total X2 do 9.4 Tons of matrix per ton of product 3 6.11 Matrix, average pumping distance mi.. 2.25 Slimes in matrix pet. . 22 Slimes per year tons or acre ft.. 10,334 Tailing million tons/yr. . 7.041 Tailings, average pumping distance mi.. 2.25 Operating time hr/yr. . 8,760 Number of operating days per year 365 Acres mined per year 267 Equipment data: Number of draglines 2 Size of draglines yd^.. 45 Number of pumping systems 2 Number of washer trains 2 Number of flotation plant trains 2 Number of dryers 1 Mine Mill Operating personnel: Operating labor 65 59 Direct production supervision 23 16 Maintenance labor 20 19 Maintenance supervision 11 11 Technical 14 13 General administrative 12 11 Total 145 129 ^Matrix X = yd^ of ore that must be processed to yield a ton of product. ^Total X = yd3 of overburden plus ore that must be handled or processed to yield a ton of product. ^(Matrix X) (density or tons/yd3) = tons of matrix/ton of product. 52 TABLE B-13. - Operating parameters for average mine (case V) (1.42 million tons of product per year; 6.58 million tons of ore per year) Production: Pebble million tons. . 0.56 Total concentrate do .86 Pebble-concentrate ratio .65 Total production million tons.. 1.42 Mining data: Matrix depth ft. . 15.6 Overburden depth ft. . 20.0 Total depth ft. . 35.6 Matrix density Ib/f t3. . 90.7 Matrix X' yd^/ton product, . 3.8 Total X2 do 9.3 Tons of matrix per ton of product^ 4.62 Matrix, average pumping distance mi. . 1,4 Slimes in matrix pet. . 28 Slimes per year tons or acre ft.. 5,043 Tailing million tons/yr. . 3. 198 Tailings, average pumping distance mi.. 1.4 Operating time hr/yr. . 8,760 Number of operating days per year 365 Acres mined per year 253 Equipment data: Number of draglines 2 Size of draglines yd 3 . . 45 Number of pumping systems 2 Number of washer trains 2 Number of flotation plant trains 2 Number of dryers 1 Mine Mill Operating personnel: Operating labor , 57 56 Direct production supervision , . , 21 14 Maintenance labor 18 17 Maintenance supervision 10 10 Technical 13 12 General administrative 11 10 Total 130 119 ^Matrix X = yd^ of ore that must be processed to yield a ton of product, ^Total X = yd^ of overburden plus ore that must be handled or processed to yield a ton of product. ^(Matrix X) (density or tons/yd^) = tons of matrix/ton of product. 53 Feed Grade . - Feed grade refers to the P2O5 concentration of the sand-size mate- rial in the ore. Generally the higher the feed grade, the lower the reagent cost incurred in the producing a ton of concentrate. Total Depth . - Total depth, the total depth in the operating pit, is the sum of the overburden and ore thickness. Gener- ally the effect of total depth on produc- tion costs is minor up to depths of 70 to 80 ft. Greater depths, however, in- crease costs through overburden rehan- dling or larger capital expenditures for draglines. Contaminant Content of Ore . - Magnesium and insoluble iron and aluminum con- tent of the ore also affect production cost. Dolomitic fragments or coating may cause problems in feed prepara- tion or flotation; high insoluble lev- els may cause flotation difficulties. High product-contaminant content may increase production cost per ton through the exclusion of otheirwise suit- able ore or through additional pro- cess requirements to make the product acceptable. Production rate is the second major factor affecting production costs. Many cost inputs into a mining operation are not directly proportional to size. As the production rate increases, the cost per ton for these relatively fixed costs decreases. All other factors being equal, larger mines in volume of produc- tion have the cost advantage. Tables B-2 through B-7 show the definite correla- tion between mine size and production cost. Capital Costs Capital costs, estimated or based on known data, are summarized in tables B-14 and B-15. The costs are for nonpro- ducing deposits (cases IV and V) in Jan- uary 1981 dollars. Capital-cost esti- mates for producing operations (in book value as of January 1978) are detailed elsewhere ( 20 ) . Capital outlay can have a profound in- fluence on unit production costs, as related to interest on invested capital and depreciation of capital facilities. Capital requirements for ore, equipment, and facilities have escalated rapidly in recent years; therefore, existing mines will incur interest and depreciation expenses on a much smaller base than newer or proposed mines. The initial capital investment on many existing mines has been largely depreciated. This depreciation was largely responsible for separating the higher production costs for the new existing mines grouped as case IIA from those of the older mines with otherwise similar characteristics grouped in case II. Other miscellaneous factors also influ- ence production costs. Long pumping dis- tances , requiring heavy expenditures for power, pumps, and pipe, force production costs upward. Mine recovery, the per- centage of the ore recovered from the mining pit, markedly affects total proj- ect economics through its influence on actual reserve costs and mine life. Although influencing the frequency of pit moves, production rate, etc., mine recov- ery is generally not a recognized major factor in direct production costs. 54 TABLE B-14. - Capital costs of typical large mine in lower quality ore (case IV) Capital cost, million dollars Mine area: Roads 0.4 Utilities 5.2 Buildings .4 Mine equipment : Prime movers (draglines).... 19.1 Hydraulic water and ore transportation 9.6 Mine-support equipment 1.9 Miscellaneous 1.2 Subtotal mine capital 37.8 Exploration and development 3.7 Land acquisition (land reserves cost) 48.2 Permitting and environmental 1.1 Working capital ( 90 days ) 5.5 Subtotal other capital 58.5 Total mine capital 96.3 Mill area: Roads .5 Utilities 2.5 Buildings (office only) 1.0 Process units: 1 Washer 22.2 Feed preparation 7.4 Reagent storage 4.9 Flotation 28.4 Water distribution and waste disposal 3.7 Wet-rock storage, drying, and shipping 7.4 Of f sites2 6.7 Subtotal mill capital Working capital (90 days ) Permitting and environmental Subtotal other capital Total mill Grand total mine an d mill 193.6 'Complete units including equipment ready to operate. ^Support facilities — shops, rails, laboratory, etc. 84. 7 12. 6 12. 6 97. 3 55 TABLE B-15. - Capital costs of typical large mine in lower quality ore (case V) Capital cost, million dollars Mine area: Roads 0.2 Utilities 3.1 Buildings .2 Mine equipment: Prime movers (draglines).. 11.4 Hydraulic water and ore transportation 5.7 Mine-support equipment 1.1 Miscellaneous .7 Subtotal mine capital 22.4 Exploration and development 2.9 Land acquisition (land reserves cost) 38.0 Permitting and environmental .8 Working capital (90 days) 3.4 Subtotal other capital 45. 1 Total mine capital 67.5 Mill area: Roads .3 Utilities 1.5 Buildings (office only) .6 Process units: 1 Washer 13.2 Feed preparation 4.4 Reagent storage 2.9 Flotation 16.9 Water distribution and waste disposal 2.2 Wet-rock, storage, drying, and shipping 4.4 Of f sites2 4.0 Subtotal mill capital 50.4 Working capital (90 days) 7.8 Permitting and environmental Subtotal other capital 7.8 Total mill 58.2 Grand total mine an d mill 125.7 ^Complete units including equipment ready to operate. ^Support facilities — shops, rails, laboratory, etc. 56 APPENDIX C. —DOMESTIC PHOSPHATE REGULATORY AND ENVIRONMENTAL CONSTRAINTS AND PERMITTING Starting up a phosphate mining opera- tion in the United States has become increasingly more difficult and time con- suming in recent years (particularly in Florida) because of regulatory require- ments, environmental studies, and lengthy permitting procedures. A number of environmental and regula- tory constraints developed in Florida over recent years reflect the public's concern that strip mining is a potential threat to two of the State's major indus- tries: tourism and agriculture. Issues of major concern to the public and, con- sequently, the State government include land aesthetics, productivity of the reclaimed land (most is now used by the agricultural industry), disruption of wildlife habitats and wetlands, clay waste disposal methods (slime ponds), extensive water usage, and radiation lev- els in overburden spoils, reclaimed soils, and sand-clay wastes. (Radiation is due to the uranium and its decay prod- ucts associated with phosphate rock.) The industry must follow an extensive permitting process to start a Florida phosphate operation. These permits force the mining companies to address those issues previously discussed. The per- mits, developed at all levels of gov- ernment (county. State, and Federal), are listed below. This extensive per- mitting is a result of public and govern- mental concern for the impact of min- ing on the local environment, economy, and culture. A detailed description of these permits appears in the Zellars- Williams MAS report on Florida phosphate availability (20). It should also be noted that present operating mines are being required to comply with many parameters included in these permits. The following is a list of most of the major permits required to develop a phos- phate operation in Florida: County Zoning Change Master Plan Approval Development Order Operating Permit Building Permit State Division of State Planning (through Regional Planning Council) : Development of Regional Impact Department of Environmental Regulation: Air Quality Permit Industrial Waste Water Permit Dredge and Fill Permit Drainage Well Permit Dam Construction Permit Potable Water Supply Permit Sanitary Waste Permit Water Management District: Consumptive Water Use Permit Water Well Construction Permit Works of the District Permit Department of Natural Resources: Recla- mation Standards Federal Environmental Protection Agency: NPDES (Water Quality) Permit Air Quality Standards Army Corps of Engineers: Dredge and Fill Permit Dam Construction in Waters of the United States Permit 57 The environmental and regulatory con- straints in the western field phosphate deposits are not so complex as those in Florida. Because nearly all phosphate deposits in the Western United States are within Federal lands, the right to mine these deposits must be obtained through a Federal lease agreement. These lease agreements specify a limit to the size of the mining operation, a rental fee (per acre), and a royalty. Leases are ob- tained through the U.S. Bureau of Land Management; development, mining, and reclamation activities are supervised by the U.S. Geological Survey. The U.S. Forest Service is involved when lands it administers are leased. Environmental impact statements are often also written before leasing a deposit. Numerous other State and Federal agencies can be in- cluded in the supervision of a phosphate mining lease. Certain environmental constraints exist in the western fields, including reclama- tion of pits and waste dumps, revegeta- tion of the mine site, and preservation of water quality. Some of the Western States have more stringent regultations than others con- cerning regulations and environmental quality. i^rU.S. GOVERNMENT PRINTING OFFICE: 1983-605-015/45 INT.-BU.OF MIN ES,PGH.,P A. 26920 9368 i aN- <^_ " • " f " k'^^ O. * ^0•' r-U ^'. ' * «? >5>-, o^ f^ %.c.^^ ^M^'" ^.♦^ /^^- v./ yjf\%id^ ^^ y- -^^ %-<^ ^ " " " " "^ j-jv- . O V ip-j-j. «5°^ .• .**%- ••■ y ^-c- •; ,*..., ■ J. ' . . » * -0 o ' o . , » o o V "^' <^* .. ^^'*«'^°'" aO' V'*^'*\^^'' "°^"^^'*^o'5 ^^^'^'^^*\^^ >o -.„-.o ' .0* ''is. LIBRARY OF CONGRESS 002 959 866 6 • ■■•1'' ',' ■{ , t ■ . . ■ Lev- i*