EXTRACTION AND UTILIZATION OF UTAH SULFUR by J O H N SHED D P R ESCOTT Til ESIS FOR THE DEGREE OP BACHELOR OP ARTS IN CHEMISTRY COLLEGE OF LIBERAL ARTS AND SCIENCES UNIVERSITY OP ILLINOIS 1921 UNIVERSITY OF ILLINOIS UJ 1/0 I 9 2__l THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY JOHN _ SHEDD_ PRESCOT T ENTITLED 1? _ AND_ _U T_I LIZ ATI ON _ OP _ U T AH _ pUpfUH IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE OF Bachelor of Arts in Chemist ry_ Digitized by the Internet Archive in 2015 https://archive.org/details/extractionutilizOOprec 1 THE EXTRACTION AND UTILIZATION OP UTAH SULFUR. TABLE OF CONTENTS. PAGE. I. INTRODUCTION 2. II. HISTORY SHOWING NECESSITY FOR RESEARCH.. 4. III. GEOLOGICAL STUDY, AND ANALYSES 6. IV. THE LEACHING PROCESS 11. Figure 1 13. Table 1 15. V. THE ROASTING PROCESS 20. VI. SUMMARY 24. VII. UTILIZATION 26. THE EXTRACTION AND UTILIZATION OP UTAH SULFUR "The very art of chemical engineering has been re- volutionized from the method of ore grading to the electric furnace or the modern electrolytic plant. From the first construction of machinery to the final loading of the finish- ed products on the car, electricity is everywhere serving faithfully in plants that seem to grow over night." This quotation, which appeared in an advertisement of the General Electric Company in a recent scientific magazine, prompted the suggestions which have been made in this paper regarding the operations of the Utah Sulfur Corporation. Thus, the problem faced by this corporation at the present time, that of determining whether or not the sulfur in the Utah deposit can be profitably extracted, and thence determining the best method by which to remove the sulfur from the ore, has been approached from the standpoint of the chemical engineer. The process of determining the best method has en- volved a study of all the methods used up to the present time with an effort to find a better method, if possible. And in order that the final process decided upon might be as nearly perfect as possible, it was necessary to study the ore deposits both from the standpoint of the geologist and the chemist. Thus th© methods used at the present time by the producers of sulfur in our southern states-- Louisana and Texas ( 1 . ) — (1) U. S. Geological Survey, July 1918, 581R. . - . ■ 3 . - and in foreign countries-- Sicily and Japan--(l.) have been studied. In each case an endeavor has been made to relate these methods to the work upon the Utah ore after a study of the advantages and disadvantages of each process. Under the topic " Utilization " is included an out- line of the extent of the market for the various forms of sulfur products, including present prices and the probable fluctuations . \ / vol. 6, (1.) Mineral Industry, 1900, Page 592. - - ■ - . .-fry . - ; 1 4 HISTORY OF THE WORK ON THE UTAH DEPOSIT SHOWING THE NECESSITY OF RESEARCH. The sulfur deposit , which is located at Morrissey Utah, some two hundred miles south of Salt Lake City, has been work- ed for a period of about thirty years at irregular intervals. In all cases, including the present workings, it appears that the methods have been very crude and unscientific, and especi- ally before the work was taken over by the Utah Sulfur Corp- oration it was evidentally only possible to work the deposit during periods of high prices. The managers of the older companies did not operate the mine with any ideas of sound business. They simply ex- tracted the high grade ore wherever it could be found, and piled the lower grade ores and the overburden to one side. This process of course made it necessary to rehandle the so called waste over and over again and finally resulted in the closing of the mine after a good part of the higher grade ores had been removed. And because of these previous workings, the mine is at the present time filled with what would previously have been considered low grade ore. The old method method of recovering the sulfur is of course the cause for this condition. ( 1. ) In most cases vertical cast iron retorts were used. These retorts were ten feet high and four feet in diameter, and were filled with the ore and heated with steam. A por- tion of the sulfur melted and was drawn off at the bottom of (1.) Report of W. Darrah upon the Utah Sulfur Corp. March, 1, 1921. I •' - K . • ■ .■ f •- ‘ i L . " ■ 5 . the retort. From the tailings at present at the mine which average about thirty percent of sulfur, it appears that from a sixty percent ore it was only possible to extract one half of the available sulfur, while from a thirty five percent ore only about fifteen percent of the sulfur was extracted. For this reason the steam re tor ting method has not been considered in any way feasible especially considering the fact that piles of tailings have accumulated from these previous workings which make it essential that a much more efficient method be used in order that the mine may be successfully operated. Never- theless, the method has been reviewed in the hope that it might suggest some better method, and also that the' difficulties en- countered might be noted so that these same difficulties might be avoided in considering a new method. In addition to this method which consists in melting the sulfur out of the ore; the leaching process, which consists in dissolving the sulfur out of the ore with carbon disulfide and then evaporating the latter leaving the sulfur, has been studied in detail. This method makes the total process much more difficult in that it neces- sitates the presence of a plant for the producing of the solvent. This process has however been investigated in an endeavor to relate this method to the production of flowers of sulfur by the use of a furnace similar to those used by the producers of carbon disulfide in the electric furnaces at Pen Yan, Pennsylvania. (1.) (1.) Manufacture of Electric Furnace for the Product- ion of Carbon Disulfide. E.R. Taylor, A.M.E.537.06 Trans Am. Electrochem Soc . ,16,229-234. 6 . A GEOLOGICAL STUDY OF THE ORE; PREVIOUS ANALYSES OF THE ORE; AND ANALYSIS CONDUCTED IN CONNECTION WITH THIS PROBLEM. I. The sulfur in all forms of the ore exists in the free state physically mixed with earth, lime and volcanic ash. (1.) There are three distinct types of ore in this deposit. 1. ) The most common ore consists of a soft light gray rhyolite carrying from ten to fifty percent of yellow sulfur distributed in a lamillar manner throughout the mass. 2. ) Next in importance is that ore made up of yellow fairly dense semi-crystaline sulfur mass intermixed with rhyolite and earth. The quantity of sulfur in this type of ore is relatively high running from fifty to as high as eighty percent. This was the type of ore that was preferred by the early operators of the mine. 3. ) The third type is somewhat similar to the prev- ious, but it is colored grayish black by the presence of upwards to twenty percent of volcanic ash containing mangan- ese and iron. According to a recent report, it is estimate: that the mine at present contains in the neighborhood of 200,000 tons of available sulfur which would allow the mine to be worked over a period of from ten to fifteen years even if the daily output of the plant should reach as high as 50 tons per day. Also it is quite interesting to note that (1.) U.S. geological Survey Bull. 515, 485-489. , J . . ' ^ ■ — ■ r ■ . J ■* * ' * '■j wi V 7 . gases are still escaping which deposit sulfur;so that there is a possibility that the mine might be worked for a longer period. II. A recent analysis of samples taken from all parts of the mine have given an average of about thirty percent sulfur. (1.) This approximately represents the average richness of the ore remaining in the mine. This of course being true only in the event that the samples were representative. However, in any case, the point to be emphasized is that any method under consideration must be able to efficiently extract the sulfur from an ore containing thirty percent or less of sulfur. From all the analyses that have come to view, none have been found that report the presence of arsenic or anti- mony. Since these substances are very undesirable in a sulfur ore because of the difficulty experienced in their removal from the final product, the value of the ore is greatly in- creased by their absence. In all reports the ore is represent' ed as a mixture of free sulfur and silica and lime with very small percentages of metallic ingredients. III. The work herein described has been confined entirely to the second type of ore. Approximately eighty pounds of ore of this type was received from Utah from which represent- ative samples amounting to twenty pounds were chosen. This (1.) Report of W. Darrah, March 1921. ' - 5 ; ' r 8 . weight was ground to about the size of a pea and was then quartered in the usual manner until a representative sample of about one half pound was obtained. This was then ground in a morter until it could be sifted through an eighty mesh seive. The remainder of the twenty pounds was then retained and has been used in all the extraction methods. Using the finely divided ore in all determinations, the ore was next analysed fDr available sulfur in case the ore was heated to vaporize the sulfur, for available sulfur by means of extraction with carbon disulfide; for silica, metallic oxides, and the lime and calcium sulfate were deter- mined by difference. A check was later taken by direct anal- ysis for sulfate. In the first case, as also in the subsequent analyses, a one gram sample was used. This sample -was then heated in a number one crucible until there was no further loss in weight. The loss in weight represented directly in percent- age the amount of sulfur in the ore. All values for this determination checked to within .2 of 60^. In the deter mination of available sulfur by the leaching method, a one gram sample was placed in a Gooch crucible which had previously been washed with carbon di- sulfide in addition to the usual method of preparation. The solvent was then run through the filter until upon drying the filter there was no further loss in weight. The avail- able sulfur by this method represented the more true value 9 . since in this case there was no possibility of the ash changing in composition as it would tend to change when heated. The small difference in the two determinations would indicate that there is very little calcium carbonate in the ore. It appears therefore that the calcium in the ore is mostly in the form of the sulfate and oxide. The value for this deter- mination was 59$. In determining the percent of silica, the sample was first heated to drive off the sulfur. The samples of ash from the first determination of sulfur may be conveniently used for this purpose.-- This ash was then fused with a sufficient weight of sodium carbonate, and the mass extract- ed with water and dilute HC1. By repeated evaporations, the silica was converted to the insoluble form, and the percent was determined by noting the loss of weight when the ignited residue was treated with HF and H2S04- in a platinum crucible. This determination gave 29 as the percentage of silicon di- oxide . The heavier oxides were determined from the filtrate from the silica determination by precipitation with NH40H according to the standard method. These values give by difference the percentage of lime and calcium sulfate as 10. 3. As indicated by the difference in the two determinations of sulfur, this repre- sents probably 2.3 $ CaC03 and 8.0$ CaS04. These last two figures being true in the case that the 1$ difference in the sulfur determinations represented a loss of C02 from the ■ • ■ • - - V J ; . . - - . * ’ 10 . limestone in the ore. This should be very close to the true value since the first residue was no heated to such a temp- erature that this difference might represent a loss in weight from the decomposition of CaS©4. In fact when this suppos- ition was checked by the direct analysis fro sulfate by pre- cipitation with BaC12, the weight of Ba S04 from a one gram sample of the ore was .1321 representing 7.69 percent CaS04. . ' 11 . THE LEACHING PROCESS. As has been previously stated, the leaching process consists in dissolving the sulfur out of the ore by means of carbon disulfide from which solution the sulfur is removed upon the evaporation of the solvent. The study of this method of production presented several definite problems. Namely, the determination of the following factors: 1.) The effect of the fineness of the ore upon the percent of sulfur extracted. 2) The volume of carbon disulfide necessary per unit of ore. 3. ) The amounts of sulfur dissolved by succeeding portions of the solvent. 4. ) The weight of the solvent held by the sulfur, and the means of removing the last traces of carbon disulfide from the final product. 5. ) The percent loss of carbon disulfide through the process . 6. ) The amount of heat required by the process, and the means of producing that heat. 7. ) The apparatus necessary to carry out the extract- ion efficiently, and the probable cost of that apparatus. 8. ) The cost of labor. In the line of the first of these problems mention- ed, the sulfur was extracted from three one -hundred gram ' o * ■ i J. t «■»... . . ^ * r ■> .. . . . . ' ' - . ■ ' . . ' w ■' ' V • . . 12 . samples of the ore. That Is, from the finely ground, the pea size, and the egg size. In each case, 200 cc. of the solvent was used, and the extraction was carried out in a sealed jar. The finely ground material of course went into solution much more rapidly than in either of the succeeding cases, hut in each case, the sulfur product weighed the same, namely 57 grams. The failure of the solvent to remove all the sulfur was probably due to an equilibrium effected in each case be- tween the solution and the solvent, due to the fact that successive portions of the solvent were not used. The exper- iment however was satisfactory in that it indicated that the fineness of the ore effects only the time element in the extraction, and showed that the ore is sufficiently porous to allow complete disintegration by the solvent. In all three cases the residue appeared finely divided in the bottom of the jar at the end of an hour period. The sulfur was removed from the solvent by allowing the pregnant solution to drop slowly upon steam heated watch glasses. No attempt was made at this time to recover the solvent. The sulfur which remained on the watch glass was scraped off from time to time in order that the extract ion might be as complete as possible. In the determination of the amounts of sulfur extracted by succeeding portions of the solvent, and the percent loss of carbon disulfide, the apparatus shown in figure 1. was constructed. This consisted of a 500cc. distilling flask (A.) 13 . 14 .. connected with the 500cc. separatory funnel (B.) in the stem of which was placed some glass wool to act as a filter and allow only the pregnant solution to pass through into the flask below. A and B were both weighed before the deter- mination, after which 200 grams of the pea sized ore was placed in B. The solvent was then introduced in portions of lOOcc. When each lOOcc. had remained in contact with the ore for ten minutes, it was then run slowly into the distill- ing flask (A. ) from which the carbon disulfide was distilled into the recovering chamber (C.). After each portion had been distilled over, the weights of A and B were taken, and the volume of solvent recovered was noted. The increase in the weight of A of course represent- ed the amount of sulfur extracted by the portion of solvent recovered in the bottle(0.}. Since the change in weight of the separatory funnel (B.) was in each case due to a loss of sulfur and an addition of carbon disulfide, the amount of the solvent which remained suspended in the ore was determin- ed by subtracting the total weight of sulfur in the flask (A.) from the total original weight of the funnel (B.), which it is evident would give the weight of the funnel in case none of the solvent had been held by the ore. This theor- etical weight without the carbon disulfide then subtracted from the actual weight of (B. ) would indicate the weight of solvent held by the ore. This weight is shown in column six of table 1. Four portions of lOOcc. each were used. ' • * r ... v C D J * 15 TABLE ONE. !• 2. 3. 4. 5. 6. Vol.l. Vol.2. Wt. B. Wt. A. Wt. S. Wt. CS2 remain- — — J-xiK* 143.5 343.5 204.0 lOOcc . 50cc . 375.0 230.0 26 g. 57.5 lOOcc . 78cc • 359.0 265.0 35 g. 76.5 lOOcc * 102cc . 315.0 300 35 g. 67.5 lOOcc . 70cc. 328.0 320. 20 g. 100 g - 79cc. 400cc . 379cc. 116 g. 579 5.25/3 loss 58 g. per 100 grams — 98.3^ efficient. 16 . In the introduction of the fourth portion, the glass wool became misplaced from the bottom of the funnel, so it was thought best to stop the proceedure in order that the results might be most accurate. Accordingly the apparatus was re- arranged, and the 100 grams of carbon disulfide remaining in (B.) was distilled into (C.). From the calculated value of 100 grams or 80cc. of carbon disulfide, 79c c. were recov- ered. It is quite possible that this 79cc. represented the total held rather than 80cc. since the latter was determined by a round about calculation. Thus, it seems quite evident that it is possible to remove practically all the carbon disulfide from the residue. It may be seen from the table that despite the fact that the apparatus was of a very crude character, the loss of carbon disulfide was only 5.25%, and the sulfur removed from the 200 gram sample weighed 116 grams indicating that the extraction was 98.3% efficient in that 58 grams of the available 59 grams of sulfur in each 100 grams of ore had been removed. In all weighings, the flasks were immediately sealed upon separation from the remainder of the apparatus, and every precaution was taken, but it is very evident that a considerable amount of the solvent could be lost in hand- ling. It appears therefore that ing ce^^rcial plant the loss should not exceed one percent. The table also indicates from a study of columns 2 and 5 that the weight of sulfur carried by the solvent decreased with each succeeding portion. 17 . In fact if the weights of sulfur carried by the solvent were calculated in each case to a corresponding weight carried by lOOcc., the weights would be 54, 45, 34, and 28.6 grams respectively. It thus appears that a very eff- icient extraction could be carried out with approximately 200cc. of the solvent for every 100 grams of the sulfur product since the solvent could be run through a series of autoclaves in such a manner that no carbon disulfide would enter the distilling chamber until completely saturated. It has been claimed as a serious difficulty to the use of the leaching process that the final product at best contains a considerable amount of carbon disulfide which decreases the value of the product. (1.) To test the re- liability of this assertion, 50 grams of sulfur prepared by this leaching process were accurately weighed out in a lOOcc. beaker of known weight. This beaker was then kept at a temperature of 40 to 50 degrees centigrade for twenty four hours during which time the sulfur was stirred several times. During the first hour of heating the sulfur smelled quite noticably of the solvent, but that odor had completely disappeared within the second hour. At the end of this per- iod the beaker was weighed and indicated a loss of .1 gram or 0.2$ due probably to carbon disulfide. In order to show that the loss had not been due to slow oxidation of the sulfur, the beaker was heated until the following day, but no further (1.) Journal of Soc. of Chem Ind. 660.5 J.S. 226, pl8. 10 . loss of weight was indicated. It thus appears that the car- hen disulfide held by the product is relatively slight and is easily eliminated. The brimstone thus produced when ground would sell for approximately fifty dollars a ton in the states surrounding Utah. The apparent difficulties surrounding the adoption of the leaching process are: 1. ) The necessity of a plant for the manufacture of carbon disulfide. 2. ) The complication of plant required to carry out the extraction. 3. ) The high quality of labor necessary. 4. ) The lack of a large supply of water at the plant. The present equipment of the Utah plant includes a quite inefficient carbon disulfide furnace , parts of which have already burned out at least once. Although the destroy- ed parts were replaced so that operations could be continued, it appears that the type of furnace is obsolete and should be replaced at the first opportunity by an electric furnace similar to that used by the manufacturers of carbon disulfide at Pen Yan,Penn. Next, this process would require storage room and pumps to handle the solvent, huge tanks or leachers in which to digest the ore, and evaporators in which the sulfur product is deposited. The condensers used in the manufacture of the solvent could of course also be used in recovering the carbon 12 disulfide. It seems highly probable that electric evaporators could be used thus eliminating the necessity of the steam boilers which would be used in the case that steam evaporators were used. This might also be an advantageous change since this type of evaporator would eliminate the use of a large amount of water which is not available at the plant at the present . It might appear that due to the necessity for the accurate manipulation of many valve3 which would have to be opened and closed in a certain and proper order, that there would be a considerable increase in the cost of labor. It is true that a good deal of responsibility would have to be placed upon the operators of the apparatus because of the great care which would have to be taken in handling the highly inflamable solvent, and that this type of labor would cost more per individual. However, the fact should not be overlooked that this labor would be less mobile than the less skilled or res- ponsible men, and therefore the decrease in the labor turnover would considerably offset the increase in the individual wages. Also it seems that this process would require fewer men to handle the equipment than either the retorting or the roast- ing processes, since the leaching process could be most nearly machine controled. It therefore seems highly probable that the cost of labor for this process would be smaller rather than larger than that required by other methods. . . l ■ • ;• J. , . ; ' . - ; ■ r— ■■■ -■ - - THE ROASTING PROCESS. In view of the difficulties which have been exper- ienced in the steam retorting process, and in the leaching process, and considering the fact that sulfur vaporizes at 450 degrees centigrade, it seemed possible that a clean cut and efficient extraction might be effected by heating the ore in a closed retort to a temperature just above the boiling point of sulfur. In the usual manner of producing flowers of sulfur, the brimstone is melted and run slowly into a retort below from which it is vaporized and collected in the form of flowers in an adjacent chamber. This contemplated roasting process would however afford a means of producing this much more valuable form of the product direct from the ore, and should thus save a considerable expense. Crude brimstone is worth approximately one third the value of flowers of sulfur. The fact that electric power, produced by hydraulic means, is available at the plant makes it seem probable that an electric furnace could easily be designed which would be very efficient due to the relative low cost of power produced by water falls. A type of furnace for this extraction might be con- structed similar to the furnaces at Pen Yan, Penn. (1.) used in the production of carbon disulfide. That is, a large vertical affair with the heat applied from the center. The ore would be introduced from the top of the surrounding (1.) J. Wright, Electric Furnaces and Industrial Appli- cations 669.8 W93e Report on Pen Yan Furnaces. - . 1 - . ' . . •' • I * . ■ - ■ . ; . : •. . F . , - . . 21 chambers very similarly to the means of introducing the mater- ials into the ordinary blast furnace. These outer portions of the furnace would serve the double purpose of melting the greater portion of the sulfur out of the ore, and utilizing the heat radiating from the central portion of the furnace. In the central section of the furnace the heat would be greatest and sufficient to drive the product into an adjacent chamber of the ordinary type used to condense the vapors in the manufacture of flowers of sulfur by the present system. Such a type of furnace would however be very difficult to construct in the laboratory; so consideration was given the possibility of using a relatively simple furnace such as used quite widely in the coke and gas industry. Accordingly two distilling retorts were constructed. The first from an iron pipe one and one half inches in diam- eter and ten inches long. This retort was sealed at the top and bottom by removable caps. At about one and one half inches from the top, a connecting tube was inserted. This tube con- sisted of a one half inch pipe one and one half feet in length. The opposite end of this tube was then introduced into the condensing chamber which was made from a common tin plated cracker box of one foot dimensions carefully sealed with asbestos paper. The second retort was similarly constructed, but was made of two inch piping rather than one and one half inch and was only six inches in length. The heat required for the distillation was furnished . * . • * ' ■ ■. , * 22 from an ordinary Case furnace capable of giving a temperature of 1000 degrees centigrade. On two occasions this furnace was replaced by an electric resistance furnace in which the one and one half inch pipe was snugly fitted, and in one trial, the tin condensing chamber was replaced by a four or five liter Florence flask which enabled the operator to watch the progress of the distillation. In the first trial, considerable difficulty was exper- ienced from the melted sulfur leaking through the pipe connect- ions which were not sufficiently sealed. This was remedied by treatment with white lead. In the next succeeding efforts, the inclosed sulfur boiled over and into the condensing chamber before the distillation was completed , and in one instance the condensing chamber exploded. This was considered due to the contact of the escaping fumes of sulfur with the Bunsen flames which were used to heat the connecting tube in order that the fumes would not condense in that tube before they reached the chamber. To prevent a reoccurance of such an explosion, a thick sheet of asbestos paper was placed between the flames and the condensing chamber. In the most successful attempt, one hundred grams of the ore, pea sized, were used, which weight filled the retort number one only one third full. In addition the whole appar- atus was so placed that the connecting tube made an angle of about thirty degrees with the horizontal in order that any liquid sulfur which reached the tube would flow back into ■ • * * j ■ :• . ■> . 23 ■■ ■■ —■■ === 11 1,1 " "" " ‘ the retort rather than into the condensing chamber. The highest temperature reached was 600 degrees centigrade. It seemed most important that the temperature should be slowly increased after the melting point of sulfur was reached. It appears that such a proceedure prevents the ash in the ore from being shaken in the retort and thence into the condensing chamber with the final product. In this instance, all precautions learned in the previous trials were observed. The product appeared identical with the commercial product of flowers of sulfur, and burned completely when tested in a small porcelain crucible. The main difficulty appeared to result from the boiling over of the sulfur which made it possible to use only a small amount of ore at one time. However this exper- iment proved conclusively that the valuable flowers of sulfur can be produced by this direct method. A furnace similar to those used at Pen Yan would seem quite possible for use with sulfur alone. In designing such a furnace two specific principles should be kept in mind which would result in high efficiency if adhered to; The first and principal aim should be toward making possible the contin- uity of furnace action, whereby the plant may be worked day and night with a consequent gain in efficiency. Secondly, there should be some device by which the raw materials may be heated prior to their introduction into the furnace, thereby involving a lesser expenditure of heat energy and electrical 2A power than would otherwise be necessary. (1.) SUMMARY . It has been shown that the steam retorting method should not be considered. Likewise, the method of mining used in Louisiana and Texas would be impossible, first because a great portion of the Utah ore is near the surface, but most important because this method is essentially only a modification of the steam retorting process, and would therefore be like- wise inefficient. A choice must then be made between the roasting and the leaching processes. It appears from the previous discussion that both can be carried out satisfactorily. Despite the apparent success of the experiment carried out with the leaching process, it seems that due to the greater value of flowers of sulfur, the roasting process would be most advisable. Economic conditions in the vicinity of Utah re- garding the ease of sale and shipment of the two varieties should however also be duly considered, and that process should be chosen which would give the most certain and steady income. For this reason it appears that the roasting process would be most satisfactory in that both brimstone and flowers of sulfur could be produced, by this method. The brimstone in this case would be obtained by melting a portion of the flow- ers. This latter step should however be effected only in the event that the quantity of flowers produced exceeded the de- mand for that substance. In the case that it might be found advisable to con- (1.0) J. Wright , Elect. Furnaces and Ind. Applications 669.8 W93c. 25 . tinue the use of the present leaching equipment rather than install the several furnaces which would be required to satisfactorily carry out the roasting process, the flowers of sulfur could be produced from the brimstone of the leach- ing process in a single furnace of the Pen Yan type which could be so designed that the carbon disulfide could be manufactured in this same furnace at such times as it would otherwise be idle. The outer portions could easily be so designed that the furnace action would be continuous. 2 £. UTILIZATION . As has been recognized in the above discussion, the market for sulfur is divided among five separate types of the element. Namely: 1. ) Crude brimstone. 2. ) Lump brimstone (refined) 3. ) Stick brimstone (refined) 4. ) Ground sulfur (brimstone) 5. ) Flowers of sulfur. Next, there are threedistinct types of industries in which these types of the product are widely used, i.e. 1.) The general manufacturing industries, 2.) Explosives industry, 3.) The agricultural industries. Most important with respect to the quantity of sulfur used by the first class are the paper and sugar industries. Producers of these substances use large quantities of sulfur for bleaching purposes. In the several states surrounding Utah, there are many sugar beet factories. These factories however use crude sulfur entirely; so should not be considered too seriously as consumers in case the roasting process is decided upon. Especial efforts should be made to produce and maintain a market for flowers of sulfur with the powder plants and the fruit ranches in the northwestern states. This would be 3 . dv i ^ sib 1 & particularly since it appears that in these states the com- petition with sulfur products from the southern states and from Japan would be at a minimum. According to the present . , . ■ - ■ , . • . . 3 ; . . ■ . ‘IC . 23L market conditions, it is evident that flowers of sulfur should show a profit to the manufacturers of at least two and one half times that which would be realized upon brimstone. It would seem safe to predict that the sulfur market will not change further from the results of the recent war, and that a steady market can be maintained through the sale of the products to the numerous ranches in the vincinity of Utah. Additional, though less extensive fields for the sale of sulfur may be found through contact with the manufacturers of sulfur dioxide, sulfuric acid, carbon disulfide, matches, fireworks, sprays, germicides, and sulfur dyes; but it is most important that relations be first established with the larger users in order that a steady market may be maintained.