!'•• ° % ^ --fife' *^ -'Sfe^ f$ffi£^* i '^°"^'M& * -P ^ '-Ili5\ ; ^°- .* ♦: ^ v : '**»<& ^ s % i* » £ "*. \ \lllK ; „^\, '-J^Wv ^ \3 <> *'T7i» .,tf >" I* 1 ** ** ^0* o V ... . • • • . *%. «. V , . „ «*• v/ --A'- W ••$&•• \< 1, vf> i0^. •• o. **o* ' 4 O ^0 VV 'vP^' V •!••- > < v %/» ° • V :f "-V* 'WW'S v^?v* %■"> v^v* 4°* * ** *^ •.'«^5 > ,* .^ "^ -.-, J *>-^k*\ **tieteS y.-^fe.\ ^^&-% /.- ^d* "o V ^o 11 iPv*. %^-\S c v^^*/ v^^y °^^^-/ v*- 77** . (1) where (1-Y av ) 77 is the average yield loss to scrap in manufacturing consumer goods from stainless steel mill products for 1977. Estimates of Obsolete Scrap Generation After a product's useful life, obsolete scrap is generated, as indicated in figure 1. Typically, stainless steel scrap so generated was fabricated from mill products produced many years earlier. The approach used in esti- mating obsolete scrap generation involved calculating apparent domestic con- sumption of stainless steel manufactured products (fig. 1). Statistics on domestic shipments were plotted from 1950 through 1977, and an equation was then developed by linear regression of this data (least squares fit) to repre- sent domestic shipments by year. The form of this equation was D = Ao + BoT (2) where D represents domestic shipments, Aq and B are constants, and T = year minus 1900; for example, T = 50, 59, 63, and 77 for the years 1950, 1959, 1963, and 1977, respectively. By plotting data on net imports over time, a similar equation was developed of the form N = A' + B'T (3) where N represents tons of net imports and A' and B' are constants. Typically, net imports have accounted for less than 10 percent of apparent domestic consumption. By adding domestic shipments (D ) to net imports (N) , one obtains appar- ent domestic consumption of steel mill products (D) : D = (Ao + A') + (Bo + B') T (4a) D = A + BT where A = Aq + A* and B = B + B 1 . (4b) For any given year, apparent domestic consumption of stainless steel manufactured goods can now be calculated in a three-step process: (1) deter- mining apparent domestic consumption of stainless steel mill products from equation 4b, (2) estimating yield losses to scrap (D-Y av D) in converting steel mill products to manufactured goods, and (3) calculating stainless steel in manufactured goods (C g ) by subtracting yield losses to scrap calculated in step 2 from apparent domestic consumption of mill products found in step 1. As a result, in any year (j) apparent domestic consumption of consumer goods containing stainless steel (C g j ) can be expressed as follows: C gj = Dj -[(l-Y av )D]j (5a) or C g i = ( Y av D >i < 5b > Market classifications were then used, as published by the American Iron and Steel Institute, to form a basis for estimating manufactured or fabricated product lives. Two approaches can be taken to estimate the product lives: Approach A . — Estimating product lifetimes by market classification (auto- motive, appliances, utensils, cutlery, etc.) and then determining shipments of stainless steel products to this market sector in the year that the product was made. Thus, for an automobile with an average product life of about 10 years, we would determine the amount of stainless steel that was consumed in the manufacture of automobiles in 1967 to determine the amount of obsolete stainless steel scrap generated from automobiles in 1977. Such an approach would demand determining apparent domestic consumption of stainless steel manufactured or fabricated products by market classification for each year that such products were manufactured that showed up as obsolete scrap in 1977. Approach B . — Classifying manufactured goods into two categories; namely, those with a short life expectancy of 10 ±5 years, and those with a long life expectancy of 20 ±5 years. One can then estimate the percent of manufactured goods made in each sector that either have a 10- or a 20-year life span. Using this approach, apparent domestic shipments and net imports of stainless steel fabricated products need be determined only for 1957 and 1967. If the distribution of steel mill products shipped to each major market classification remains constant over time, either of the above two approaches would give essentially the same results, assuming a consistent set of data is applied to the linear equations developed on apparent domestic consumption. That is, an estimate of a 15-year life for products in a given market classi- fication would be equivalent to assuming that 50 percent of the products have a 10-year life and 50 percent of the products have a 20-year life on the average . Except in a few instances, data on product lives by AISI market classifi- cation are extremely limited. Thus, there is little to recommend one approach over the other. As a result, approach B was chosen because (1) this approach reduced the number of calculations one had to perform on shipments by market sector by year, and (2) as better data become available on product lifetimes, it will be easier to update this study. The mix of short-term and long-term product lives used in a given market sector was largely based on judgments rendered by industry personnel. Where better information was readily avail- able (for example, lives of automobiles), such data were used. Designating the average life in years of products using stainless steel to be L, the obso- lete scrap generation rate (G obs ) in 1977 is given by apparent consumption of manufactured goods "L" years ago: G obs = C gt (6a) = 0f av D) t (6b) where t = 1977-L (t is the average year in which goods were manufactured that are being discarded today) . Total scrap generation (G) is then obtained by adding equation 1 for prompt scrap to equation 6b for obsolete scrap, or G = (D-Y av D) 77 + (Y av D) t (7) Scrap Generation Versus Collection As indicated in figure 1, only a fraction of the scrap generated is col- lected and the remainder remains uncollected. Data are published monthly by the Bureau of Mines on stainless steel scrap receipts by melters ( 13 ) . By neglecting inventory changes, receipts are assumed equal to consumption, S . o Scrap Imports and Exports Although data on exports of stainless steel scrap in 1977 were avail- able, there were no comparable statistics for the imports of stainless steel scrap. However, the U.S. Department of Commerce collects information on the total amount of ferrous scrap imported ( 14 ) and breaks down data on ferrous scrap on which import duties were and were not levied. Stainless steel scrap imports were estimated based upon these statistics and the judgments offered by scrap dealers and U.S. Department of Commerce officials. By adding esti- mated net scrap exports (S E ) to scrap consumption (S o ) , we obtain total domestic collection of scrap (S) : S = S o + S E . (8) 10 Estimates of Uncollected Stainless Steel Scrap The quantity of uncollected stainless steel scrap in 1977 (U) is then estimated simply as the difference between scrap collected in 1977 (S__) and scrap generated : ,U = G + + G . - S__ (9a) pr ompt obs 7 7 - (D - Y av D >77 + ( Y av D >t " S 7 7 (9b) where (D-Y V D) 77 = prompt scrap generation, (Y D) = obsolete scrap generation, a v t and S„„ = scrap collection. 77 r Based on discussions with recyclers, a preliminary assessment of the main sources of uncollected scrap was undertaken. This included a limited survey of opinion by recyclers and other scrap industry experts as to the percent of obsolete scrap generated that was actually collected. Major sources of poten- tial error were then examined, and additional data needs were identified. APPARENT DOMESTIC CONSUMPTION OF STAINLESS STEEL MILL PRODUCTS Domestic Shipments Ingots produced by stainless steel melters are subsequently formed into semifinished products such as slabs, billets, or, in some cases, blooms. Because of economies achieved, these semifinished shapes can be produced in an alternative fashion by continuous casting, which has rapidly gained accept- ance over conventional ingot casting. Home scrap is generated as the semi- finished products are rolled in steel mills into final shapes such as bars, rods, sheets, strips, or plates. Such scrap is also generated when semifin- ished or partially finished products are sent to nonintegrated finishing operations, such as strip rerollers, wire drawers, or specialized pipe and tube makers. Since such scrap is typically handled by recyclers, it is classified as prompt industrial scrap rather than as home scrap and thus is included in the scope of this study. Since semifinished products have accounted for only about 5 percent of domestic stainless steel mill shipments, as reported by the AISI, the pre- dominant and most important steel mill shipments are finished steel mill products. The finished and semifinished steel mill products are shipped by truck or rail to distributors (steel service centers), manufacturers, fabri- cators, or exporters. In 1977, 1,860,000 tons of stainless and heat-resisting steels were poured, resulting in domestic shipments of 1,120,000 tons of finished prod- ucts (1). Most of the difference — 750,000 tons, or 40 percent of molten steel production — is home scrap; 676,000 tons of such scrap were melted in 1977. The difference is accounted for by slags, dusts, mill scale, and grinding 11 CO c o ■a c CO CO 3 O sz w 1,200 1,100 - 1,000 900 800 700 600 - 5: 500 g 400 LU £ o Q 300 200 100 1950 1952 1954 1956 1958 1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 FIGURE 2. - Domestic shipments of stainless steel. residues; some of these waste materials find their way back to the melting stage with or without intermediate treatment. Domestic shipments of stainless steel mill products as reported by the AISI (1) are plotted in figure 2 from 1950 through 1977. A "best line" through the data points determined by linear regression ("least squares fit") yields an equation of the form where D = minus 1900. D = 21.24 T - 595.9, (10) o thousand tons of domestic stainless steel shipments and T = year Net Imports Figure 3 shows Department of Commerce data (14) on net imports of stain- less steel mill products. Published information before 1964 was not readily available. A "best line" developed by linear regression ("least squares fit") through the data points yields the following equation: N = 6.007 T - 355.4 (11) 325-969 0-80-3 12 c o TJ c (B (0 3 O .C CO 300 200 100 - E o Q. I o -100 1960 - • V =6.01T • 355 -"V __•_ "V • • • • • I • I I I I I T=YEAR - 1900 I 1962 1964 1966 1968 1970 1972 1974 1976 FIGURE 3. - Net imports of stainless steel. 1978 1980 1982 where N = thousand tons of net imports of stainless steel mill products, and T = year minus 1900. Equation for Apparent Domestic Consumption Addition of domestic shipments (S) to net imports (N) gives apparent domestic consumption of stainless steel mill products (D) : D = 27.24 T - 951.3 (12) Taking cognizance of the years over which the data support this equation, the relationship proves especially useful in calculations involving obsolete scrap generation. Apparent domestic consumption is used for estimating scrap generation, as discussed in the next section. SCRAP GENERATION AND COLLECTION Estimates of Scrap Generation Prompt Industrial Scrap In its Annual Statistical Report, the American Iron and Steel Institute (1) publishes net domestic shipments of stainless steel mill products (includ- ing heat-resistant alloys), as summarized in the first columns of table 1. Net imports derived from Department of Commerce data by major product category are then added to domestic shipments in table 1 to arrive at apparent domestic consumption of steel mill products. The semifinished products are distributed to finished steel mill product categories using a 60-percent yield. This yield is based on an average value calculated from AISI data for 1977 (1) on net shipments of stainless steel mill products (1,120,000 tons in 1977) divided by production of 1,860,000 tons of raw steel (that is, the first solid state after melting, including ingots, strand or pressure-cast blooms, billets, slabs, or other product forms). The 13 difference, amounting to 40 percent of the weight of semifinished products shipped to processors other than steel mills, is assumed to be prompt industrial scrap. Thus, 33,900 tons of steel-mill- type finished products are produced from semi- finished products (60 percent of 56.5), which simultaneously results in 22,600 tons of prompt industrial scrap being generated. TABLE 1 . - Apparent domestic consumption of stainless steel mill products in 1977 (Thousand tons) Domestic shipments 1 Imports minus exports 2 Apparent domestic consumption Product Steel mill products, semifinished and finished 3 Finished products manufactured from semifinished Finished products Semifinished (ingots, steel castings, blooms, slabs, 60.3 -3.8 > 44.6 7 4.6 > 21.8 15.1 > 25.8 56.5 95.1 90.4 146.4 47.4 790.6 NAp 2.8 2.6 4.2 1.4 22.9 NAp Finished products: Wire products : 24,7 25.8 6 97.9 Total 50.5 85.8 6 93.0 Bars: 37.8 86.8 5 150.6 Total 124.6 32.3 6 48.8 Sheet and strip: 22.6 474.4 4.8 263.0 6 813.5 764.8 1,118.3 108.1 1,226.4 33.9 1,203.8 NAp Not applicable. 1 AISI Annual Statistical Report, 1977 (1) . 2 Steel Mill Products, U.S. Department of Commerce, Bureau of the Census, 1977 (as reported in reference 1) . 3 Apparent domestic consumption = shipments from U.S. mills plus imports minus exports. ^Calculated by allocating semifinished product category shipments to finished prod- uct categories in proportion to tonnage of finished products and assuming a 40 percent yield loss to scrap. The yield loss to scrap agrees with reported domestic shipments by AISI of 1,118,000 tons and crude steel production of 1,862,000 tons in 1977. 5 AISI identifies wire rod as a semifinished product. For convenience in estimating prompt scrap generation, wire rod is classified with wire products in this study. 6 Addition of prior 2 columns of finished products. 7 Includes stainless steel structurals which are not reported separately. 14 The 33,900 tons were then allocated to finished-product categories in proportion to apparent domestic consumption of finished steel mill products. For example, in table 1, 2,600 of the 33,900 tons is allocated to plate cate- gory as follows: 33.9 (90. 4)/ (1,226. 4 - 56.5) = 2.6. This is then added to the 90 , 400 tons of plates from domestic shipments and net imports to arrive at a calculated apparent domestic consumption of plates amounting to 93,000 tons. The results of the allocation calculations for the other product cate- gories are also summarized in table 1, which shows total apparent consumption of steel mill finished products to be 1,203,800 tons in 1977. These finished- product categories and consumption tonnages are now used to calculate prompt industrial scrap generation. The stainless steel mill products are consumed in turn by manufacturing operations that produce prompt industrial scrap. Since data on scrap genera- tion from manufacturing operations were not readily available, prompt indus- trial scrap generation rates for stainless steel consumed were estimated by type of product (bar, sheet and strip, etc.) used in manufacturing operations, Table 2 shows stainless steel yield losses to scrap based on judgments or estimates made by manufacturers and other industry personnel. Based on these yield losses, table 2 also shows calculations on prompt industrial scrap generated. For example, a 15-percent yield loss to scrap applied to 97,900 tons of stainless steel plates consumed in manufacturing operations results in 14,000 tons of scrap, as shown in the last column of table 2. TABLE 2. - Estimated stainless steel prompt scrap generation in 1977 (Thousand tons) Stainless steel mill product Apparent domestic consumption Yield loss to scrap Estimated prompt industrial scrap generated 97.9 93.0 150.6 48.8 813.5 NAp 60.3 10.0 15.0 40.0 10.0 12.5 NAp 34.5 9.8 14.0 60.2 4.9 101.7 Total 190.6 Scrap generated outside of steel mills in producing finished products from semi- finished (for example, ingots, blooms, *22.6 Total estimated prompt industrial NAp NAp 213.2 NAp Not applicable. Calculated by difference between total of 33,900 tons resulting from 56,500 tons of semifinished products steel mills; see table 1. Source: Arthur D. Little, Inc., estimates. of finished products consumed outside of 15 After adding prompt industrial scrap produced from consumption of bars, sheet and strip, etc., total prompt industrial scrap generated from consump- tion of finished shapes is 190,600 tons. To this we add the 22,600 tons of prompt industrial scrap estimated earlier as resulting from conversion of semifinished steel mill products to finished forms. As a result, total prompt scrap generation is calculated to be 213,200 tons (table 2). Obsolete Scrap Production of Manufactured Goods As discussed on pages 12-14, estimates of prompt industrial scrap in 1977 were calculated on the basis of yield losses occurring during the manufacture of consumer goods from stainless steel mill products. By calculating the dif- ference between prompt industrial scrap generation and apparent domestic con- sumption of stainless steel mill products, the amount of stainless steel actually entering the manufactured product can be estimated: {tons of stainless steel 1 f tons of stainless ] ["tons of prompt indus-1 in manufactured productsj [steel mill productsj [trial scrap generatedj (13) At the end of a manufactured product's life, obsolete scrap is generated. To calculate the tons of obsolete scrap generated, one needs estimates of the tons of stainless steel originally used in the manufacture of goods being discarded in 1977. Recognizing that the methodology used in this study calls for distribu- ting lives of manufactured goods into short-term (10-year lives) and long-term (20-year lives) categories, estimates were first made of the tons of stainless steel entering goods manufactured in 1967 and 1957, starting with table 3, which shows published statistics on apparent domestic consumption of steel mill products by market classification for 1967. Two adjustments were made to table 3. In estimating prompt industrial scrap generation in 1977 at the beginning of this section, yields of 60 percent were assumed from semifinished to finished steel mill products. Similarly, in making the first adjustment to table 3, the semifinished products of table 3 were allocated to finished stainless steel mill product categories in table 4 by using a 60-percent yield. Steel mill goods resulting from the semifinished product were dis- tributed in proportion to apparent consumption of finished steel mill prod- ucts. A second adjustment was then made because of a lack of data for making lifetime estimates for goods in five market classifications: (1) Steel for converting and processing, (2) steel service centers and distributors, (3) exports (reporting companies only), (4) nonclassified shipments, and (5) net imports. As a result, tonnage consumed in these sectors was allocated to the other market sectors in proportion to their apparent domestic consump- tion as shown in table 3. Results of these two adjustments are shown in table 4 as the adjusted distribution of stainless steel mill product consump- tion by market classification. Apparent domestic consumption from table 3 and adjusted distribution from table 4 are summarized in the first two numerical columns of table 5 . 16 CO s o is VO on rH 3 •rl CO 4-1 O 3 n3 O J-4 a a) CU u CO CD CO cu rH 3 •rl <4-l O £3 O •H ! 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CO v£> m c\ o (•^■OvOOOONCOrHOCMrHrHmr^CM CN 00 ON o VO ON * •V aj cu co O OmCMOO 4-1 > CO p > N 3 3 •-N 3 CO «r - •r CO • 3 a 5- XT •H >. o CO <4- ' J- 3 CU toO ' 4-J E a CU Ph rH •H 0) T- ' 4- CU g 3 3 c ^ I— a 3 4-1 CJ CC ' cr 4-1 • Cv •H ' CU ■I- 4- rH •H o CO O CC ' •r- 3 ■ •H 5-1 g ^ z CO rC O 5-, re < X •H - 3 N CO - •H ftr- ' CO CT* ^2 - •H a o 5-4 CU 4-1 c < X s • CU g ' 3 X 5-1 X CO -H • •H X) p ( 3 • crx p CU 3 4-1 3 • CO 3 a ■ cc toO - CU rH < CU 3 cc g cd •H cO Cf • CO co h « 3 ' 3 cd g rH P, 4- • CO CU < a •h a < •H X • rH i » o 00 •H g p m ■H 00 X tt 5- X 4- ■ u toO 3 ■ CO > •> cc o 3 g o a • • 1 a 3 & J. a 3 c ■ p CO 3 cd ■ •H 5-* H •H CJ E . . 1 •H (U a 4- rH 3 . c g ' •r) 5-1 cu •H X too 5-i P J • 4-1 4-1 CC c p O X . •r ' rH toC • 4-1 c cc 3 cd CU toO t • CU U r^ a a 3 C < 4- X - rH 3 ■ CO •H 3 CO ^ rti 3 4= # ^ cu a +J c •H 5- < cc 3 - •H -H < 3 £ a CJ 4-1 -H CC • u > cc P ■1 ' 4- CO ■ 5-i !>, « X o 4J CJ cd O 4-1 3 3 4J cc a •N 5- ' X 5-1 < 3 cd 33 •H p. 5-4 X • £ o c <4- c 3 - c 60 < 5-J H •H B 4-1 X O CU • O 3 1- o cc < p - 3 ' CO CO cd 1 i CO »v ti o,t^ CO • v_ ' H > •H !m cu V. •H < CO 3 5j •> rH CO CU CO CO CU «4-| 4-1 rH 5-1 cc 5- 4-1 O > c X < toO a 4 3 >•. cd cu g u 5-1 -H 5-i cO O CO •rl a O 4J •H rt ^-\ 4J 4J 5-1 a a o 0) CU v-/ cc O 4-1 14-4 bl 3 !-i cc 3 C 4J rt •H iw X •> i-H CU •rl 3 X 3 CJ CO PU O 3 4-J U cd o 4-1 3 cc 3 too 3 3 5-i cd •H 3 4J cd g H r-{ «H CO H 4-1 54 6 x> u co 3 a •H 4-J •H 5^ cd CO 5-4 H •H ai toi D 3 a CD 4-J o rH 3, a •H «H r3 a rH cu 4-1 3 O CJ CU n X ai 3 3 4J •H •H J-i rH 3 5-1 o CU p ,rC 3 X P: 3 4-1 4-1 3 4-1 o o 3 cc r3 'H •H -H toi ) CO rH p < 4-1 o 5-1 X O CU 1 C/3 Pn H en CJ u < Pi C/3 <3 o a < a w < o CJ o w s a CJ 3 X o 5-1 Cu X CU ,3 CO •H 3 •rl <4H •H g CU CO M-l o 3 o •H CO 54 CU 3" O CJ g o 5-1 MH ft CO 54 CJ CO cd •H 5-i 4J CD 3 X 4-1 o 5-1 • ft CO 4-1 CO CJ CU 3 X X 3 O r-\ 5-1 ft CO 3 o •rH 4-1 CO rH 3 CJ rH CO CJ 4-1 4-1 •rl 5-4 3 ,3 4J 5-1 <1 X 3 cO co CU r-\ rQ CO H CO CU o 5-1 3 O CO 19 To determine the tons of stainless steel used in manufactured goods, we calculate scrap generated in the manufacturing process (such as prompt indus- trial scrap generated in 1967) as was done for the year 1977 at the beginning of this section. For example, in the industrial fastener sector, 24,536 tons of wire products, 15,965 tons of bars, and 2,306 tons of sheet and strip were consumed with estimated prompt industrial scrap generation rates of 10, 40, and 12.5 percent, respectively. Table 5 shows that in 1967 this resulted in prompt industrial scrap generation in the "industrial fasteners" sector of 9,128 tons (0.10 x 24,536 + 0.40 x 15,965 + 0.125 x 2,306). Thus, of the 42,807 tons of steel mill products consumed in the fasteners sector, 9,128 became scrap and the difference of 33,679 became a part of manufactured goods in 1967 as summarized in table 5. Similar calculations were performed to determine the stainless steel consumed by goods manufactured in the other market classifications. Results, as shown in table 5, indicate that manufac- tured goods in 1967 consumed 713,181 tons of the 871,422 tons of apparent domestic consumption, with the difference of 158,241 tons reporting to scrap. The last column of table 5 shows the percent distribution of stainless steel by consuming sector. Finally, an adjustment was made to eliminate biases that could be intro- duced if the year 1967 were an unusually high or low year for apparent domes- tic consumption. From the regression equation (equation 12) developed earlier in this study, a rounded value for apparent domestic consumption was calcu- lated to be 874,000 tons, compared with the published data of 871,400 tons as shown in table 5 . Tonnage shipments by markets shown in table 6 were arrived at by multiplying 874,000 by the percent distribution by market classification shown in table 5. i Similarly, starting with published data for the year 1957 as shown in appendix A, this same procedure was followed to estimate consumption of stain- less steel in manufactured goods with results summarized in table 6. However, there is one exception; namely, data on exports and imports on stainless steel mill products were not readily available for 1957. The regression equation on imports extrapolated back to 1957 indicates minus 13,000 tons of net imports (in other words exports) in 1957, which is about 3 percent of domestic ship- ments. Because it was suspected that exports were relatively small and in the absence of better available data, a value of zero was assigned to net stainless steel imports in 1957. This is equivalent to assuming apparent domes- tic consumption is equal to domestic shipments in 1957. Product Lifetimes With few exceptions, published data on product lives by market classifi- cation were not available. Product lives were estimated by determining through discussions with manufacturers and recyclers what fraction of the goods manu- factured in a market sector in a given year could be expected to have a 10-year (±5 years) life and what fraction could be expected to have a 20-year (±5 years) life. For example, in the appliances, utensils, and cutlery classifi- cation, 90 percent of the products were estimated to have a 10-year average life and 10 percent a 20-year average life, and all products in the automotive sector were estimated to have a 10-year life (10) . The results of this study on lifetime estimates in the other market classifications are shown in table 7. 20 d o •H +J CO O •H <4h •H CO CO co CU u cO 6 >> X> CO -o o o bO -d cu 4-1 CJ cO MH co e G •H MH O CU CO d cu 4-1 CO rH o tH CO C_> vO W PQ «J H T) nj CU 0» r4 4-J d - O CN o s VO CN \r CN 1- on m CT. IT I s * rH vO r~ rH cd 4-» CO CO 00 vO CN r> VO CN ON VO f m st m t — VC 00 O st rH CJ T3 d o r^ O C r^ cn r-> st sj co vo r^ o- c^- st m st CM 3 CO O o l 1 st CO m rH 3 M CO 1 — sj st CN CO SJ c co rH rH CO C CN H 1 — r^ u CO S vo ON A rH TJ CU d o 5-i •H 4-> m CM vO r- vo co m oo c ON CO O CN I/) st CO 00 3 CO 4-1 d o oo r^ o ON ON vO r>. ON CN CN H cm n r~- rH CM vO CO C o o 4-J TJ d CU CJ o ,ri CJ o st rH U CO oo m u rH o CO O «H S-( CO rH rH o 4-J bO !-i (U rH 3 4-1 a d CO •rl T3 T3 -a CU cu M 4-J 3 » m iH OOHmN O st m CO st st r rH CO on r CM m CM rH 3 tot) rH M CM N CO ON r— m cm as CO d rH st O CO B m ON «v rH -a cu d o u •H 4J VO CM co m CTi CN O VO O r> 1 — I m CJN m d CO 4J d o st on o CN 1 CTi VO 00 O-y CTi C\ CN CM rH on r-- oo in rH O C o 4-> ■d d CU CJ O ,0 (JOHN st s vO ON c^ rH st rH o CO o -h !H CO rH rH o M-l bO n CU rH 3 4-1 D< d CO CO •H s T3 • ■ • , . CO i • » • rH CO • cO ' rH > • •H • O > • rJ O > 4-1 (U • CO 4-J d 4-1 ' u CU cO ' o -d S B bo^- \ • 4-1 a d a d -p • d c f 4- •H bO CO •h a rQ p ' 4- P > n d d r- \ • a CO T •H cc p 00 ' 9\ a 1- cr •H > -1 • o CO u- > JH c , a « d 4-1 E a cu d- 1 • •H CU •<- 4-J a ' E •H d P U I— Pu P 9 4-1 CJ CT CO 4- 1 p u u CU •r 4- rH •H c • CO O cr •H e , •r cu 8 f- P CO ^3 O U cc T3 •r « ^ < rD d- C r 1 C •H CO >N V ♦ •H &r cc ' c f ^ •H a CJ u a • m C < ■d E a > 3 d X M T3 CO -r • •H •d d rH ' cr t: P 0) d 4-1 P t CO d a < cO to a cu p cc g cO •H CC CO • CO cO r- < p ( p T3 •x g rH P u 4J • CO a « CO •r- Cf •r ' d rH » o bO •H E d • rH bOX. cr rJ X 4- J- < to CO ' CO > 1 Cf CJ d S C cu • O d & r- cu F" c p cc p •H i- 1— •H c 6 • •H a c Ll • 4- ct J- >. "d c 4- CJ CO O 4- • CO d 4J ct cu n r- t: M < d cc s •H Pu !- nc) • 2 O n- o p fc c to D rJ rH «H E 4-1 T3 C CU • o d •H c cr p u p , Cf cO cO 1 » CO n d p UvH • •^ ' H > •!- !- a Cf •r ' cc d ^ •» r- Cf CU CO co a MH rH M Ct M 4- c > p TJ . 01 a- d >n cC a El u r- •H CO O 03 •r- CU c 4- ■r cc r- 4- 4-1 r4 c, c o cu » O CN rH O l^~ CO CTi en cm m 1^ CO CU cO cd r«s CO OH r^ H r-^ cj\ •* ocn r^ vo 00 o CN «* st o r-\ 4-1 rH M h CT\ d O O cu rH o 1^ r - i rH VI- rd cu d CN rH rH VO O bO •H tH CU 1 X) CO cu CJ r^ CU d 4J M-) co VO X o CO o IW CTn M •u oo r*>. cti r-» vo o c O CTi rH m en d H cO O rH ONOO 00 O CM 00 00 VO en m oo r^ rH CO •u d O VO 00 COM N cm o cm . r. r. fl xj CU o rH j-j 131 CTv ^ vt CM VO rH CTi en r-\ rH o fl d CO X) ^ CM in bO •H co o o Xl o CU M X) d d XI +j o d CO •H CU en 60 ■P ■5 1 1 d ■rl CO 43 •P CU 4J •rl CO •rl IH rl cO & U •rl O 4-1 rH CO rH 43 S o d CU o ld m o o o o u o m m m P- C/3 CU o >■, CU rH CO oc CT\ CTN < CJ +J •rl 1 bO rH B VI CU 4-1 o CO CU Ai cd rH u P-t f-l ccS CJ •H M-f cu > CO iH CU 1 X) CO CU o r^- cu d 4-> m CO m Xl o CO o m o> U 4-J r^ rH o m o r^ cj\ o in cm oo cti en en o en r^. d rH cO vo tTi rH CN H CO H J d o d cu o m m o o c o m c m m P- CU o >> cu CTi VO m CTi o c en m r- m VO i — r— CO rH ; I 1 • CO • • ' Cu •H >> • CO > »H • CJ ■ x) • u • d d T3 !h • d • cd • o a 4 d CU cO • 4-1 • •H bO CU cu CO Ej •H • ■u d d cu T3 g ► «\ • iH • CO •H a 1 •H CJ d rH ft o bO • •H • o V 'd 4- u cO >~. cO cO > 4-1 CO o d • Ei • •H i- d C • d < a. 5h •H > d rH •H CO m a rH T- o e CO +J •> U ■ CU -H XI bOrH U ' •rl c O X •H O 10 00 4-1 El co d CO CO CU • CO a d c 4J T3 u d d co cr a. d cO AJ -H ^ ' CO 4- •H ' J. • CO d CU T3 «H d r- •H CU O W 4-1 • cO • cr p Li • 4J CO co d >•» T3 C d 4-i a cO CU O • iH ee « M •H H d c cr 3 •rl PL. 4J CJ >4- d a o c O toO a d 13 H d CO CO 1 — ec •H 4- cu 4-1 CO cO - El X3 • d • 4-1 ► r" •H p V a CO -H 4- cO cO pi b S- •> X rH CO CU 4- CO CO rH cu CC 4J CC c > d ^3 P bO o 4 p r- t^ c cO CU 6 P U bO CO 4*5 Cf 1 T CJ C 4- •r CO rH a 4-1 'r +: 5h cc CJ CJ > -. o a cu d CU 4-i !-i to !- d a C 4- H -H E m t) - J- i— CU •H pi s- X) E d «h CJ O J3 p 4- U 4- ec c 4J S Q u co d bo a p d » M cO a P U 'H CX d h s ■r C/ 4-1 C y E rO •r U cO C 4= c •H 4- 4-J -H i — u •r CO P. CO b z CO «r 4- c T-\ P- i- CJ -HE •r 43 P CJ rH 4- a) i— 4J -H d J- t: d ec q 4- •H -H E r 4 f-4 rH d r J- o a cu a r- 43 E f d rC XI C c O g C 5 cO 43 a •H «H 'H r- b CO E rH Cu Z 4-1 a O CO M P* r- e_) C < Pi en < C s < £ W <3 o u o 43 cO CJ •H rH PL* PL. CO a, 22 Obsolete Scrap Calculation By multiplying 1967 consumption of 108,367 tons in the "appliances, uten- sils, and cutlery" classification (table 6) by 0.90 and the 1957 consumption of 57,630 tons by 0.10, one arrives at 97,530 and 5,763 tons of obsolete scrap respectively for 10-year life and 20-year life categories. This gives a total of 103,293 tons of obsolete stainless steel scrap generated in this category as shown in table 7. Results of applying the same procedure to the other market sectors are also summarized in table 7, showing total estimated obso- lete scrap generation to be 648,170 net tons, which is rounded off to 648,000 net tons in further calculations. Total Stainless Steel Scrap Generated Table 8 shows the estimated total of prompt industrial and obsolete scrap generated in 1977 to be 861,000 tons. The fraction of this scrap that is actually recycled is estimated after determining stainless steel scrap exports and imports. TABLE 8 . - Estimated total stainless steel scrap generation in 1977 (thousand tons) Prompt industrial scrap (table 2) 213 Obsolete scrap (table 7) 648 Total 861 Scrap Collection (Published Data) Scrap Receipts In its monthly Mineral Industry Surveys ( 13) , the Bureau of Mines shows statistics gathered on stainless steel scrap. The statistics of interest are classified under the category of receipts of scrap by melters from brokers, dealers, and outside sources which amounted to 424,000 tons in 1977 as described in appendix E. Foreign Trade Part of the stainless (and heat-resisting alloy) scrap collected domes- tically is exported, with exports in 1977 amounting to about 75,000 net tons, as shown in table 9. It appears that 1977 was a normal year in terms of stainless steel scrap exports. No indication was found that the chromium shipped out of the country contained in stainless steel was any less desirable than that which was recycled domestically. 23 TABLE 9. - U.S. stainless steel scrap exports (thousand tons) 1 1974 35 .0 1975 76.9 1976 112 .2 1977 74.7 x Data reported in gross tons by Teplitz ( 11 ) , multiplied by 1.12 to obtain net tons. Imports of stainless steel scrap are included in U.S. Department of Commerce statistics shown in table 10, as part of the 65,956 tons of ferrous scrap on which an import duty was levied. Scrap dealers and contacts at the U.S. Department of Commerce have commented that stainless and heat-resisting alloys imports are a "very small" portion of that scrap, but data have not been found to quantify such opinions. Thus, three approaches were followed: 1. The phrase "very small" was interpreted to mean that 10 percent (or less) of 66,000 net tons on which imports are based is stainless steel scrap, to arrive at a value of 6,600 net tons of stainless steel scrap. 2. Table 10 shows that iron scrap subject to duty accounts for about 11 percent of ferrous scrap imports, which is approximately the same as alloy and stainless steel production as a percent of total U.S. steel production (including alloy, stainless, and carbon steel grades). AISI statistics indi- cate that stainless and alloy steel shipments together have been about 10 per- cent (±2 percent) of total steel shipments. Using those ratios for domestic shipments of steel mill products and assuming they apply to scrap, the follow- ing procedure was followed: Historical records CO indicate that stainless steel production in the United States over the past 10 years has been about 7 to 14 percent alloy steel production. If it is assumed that ferrous scrap imports on which duties were levied (66,000 tons) exhibit the same ratio of alloy to stainless, one arrives at stainless steel scrap imports of 4,600 to 9,240 net tons (0.07 x 66,000 to 0.14 x 66,000). 3. It is noted that U.S. stainless steel production over the past 29 years has accounted for 0.9 to 1.5 percent of total steel production. If ferrous scrap imports are in the same ratio, calculate 0.9 to 1.5 percent of the 616,000 tons of total ferrous scrap imports to be stainless steel, or 5,500 to 9,200 tons. Combining the three approaches indicates that a likely value for stainless steel scrap imports would fall between 5,000 and 9,000 tons. Seven thousand tons is used in further calculations, which is about 10 percent of the weight of the ferrous imports on which duties are levied. Clearly better import data are needed to confirm these rather subjective estimates . 24 TABLE 10. - Ferrous scrap imports in 1977 (tons) ( 14 ) Tin plate 12 , 500 Iron scrap not subject to import duty 537,067 Iron scrap subject to import duty 1 65,956 Total 1977 imports 615 , 523 Alloys containing more than any of the following were subject to import duty: 0.2 percent Cr, 0.1 percent Mo, 0.3 percent W, and 0.1 percent V. Total Prompt Industrial and Obsolete Scrap Collected Upon addition of net exports to receipts by melters, total prompt indus- trial and obsolete scrap collected is about 492,000 net tons, as shown in table 11. TABLE 11. - Domestic scrap collection (thousand tons) Prompt industrial and obsolete scrap received by melters (domestic receipts) *424 Exports 2 75 Imports 7 Net exports 68 Total 492 1 Bureau of Mines ( 13 , May 1978) . 2 American Metal Market (2) . 3 Arthur D. Little, Inc., estimate based on Department of Commerce data. UNRECOVERED CHROMIUM VALUES Calculation of Unrecovered Fraction The quantity (U) of stainless steel values lost or otherwise not recycled can be estimated as the difference between (S) scrap collected (492,000 tons) and (G) scrap generated (861,000 tons). Few direct data are available on this unrecovered scrap (U) amounting to 369,000 tons. The following sections sum- marize some findings from discussions with recyclers and manufacturers on chromium values that appear to be unrecycled. Prompt Industrial Scrap Little prompt industrial scrap is unrecycled since it is not economic for metal fabricators to accumulate rather than sell the scrap they generate. Generally they arrange with a scrap dealer to sell the high-value materials (such as well-segregated solids) provided the scrap dealer takes other scrap as well. This was found to be a common practice for both open spot bids and long-term contract agreements. 25 Industrial recovery of chromium from the 400-series stainless and heat- resisting alloys has been the subject of some controversy. The chromium in stainless steel is of much less value than the nickel. Before the AOD process was developed, industry contacts indicate that about 15 percent of the total chromium content of the steelmaking furnace charge was lost in slag and dust. Today, however, chromium recovery is in the 92- to 96-percent range in the duplex electric arc furnace-AOD process, regardless of the ratio of scrap to virgin elements. Well-segregated 400-series stainless steel scrap sells for nearly twice the price of carbon steel scrap and is thus a relatively high valued material that is unlikely to be downgraded. However, two factors hinder the recycling of prompt 400-series stainless steel scrap: transporta- tion costs and contamination. Transportation costs for scrap can be substan- tial, since the few melters are located mainly in the Midwest or on the East Coast. This geographic imbalance between scrap supply centers and scrap con- sumption centers slows down trade in 400-series scrap in times of low prices. This does not mean that the scrap will not be recycled, but it may be allowed to accumulate in a scrap yard until prices rise to a level where it becomes economical to sell. Contamination is a major concern of the recycler. Prompt industrial scrap is usually well segregated into the 400 and 300 series with the latter often segregated into molybdenum-containing and non-molybdenum-containing types. In addition, nickel-chromium steels are almost always segregated and recycled with only small losses since nickel has been a relatively high valued metal. Nickel is recovered upon remelting, losses to slags are small, and furnace dust recycling technologies now coming into increasing use also recover the nickel that previously was not recycled from pollution control equipment dusts and sludges. In addition, proper segregation of nickel- containing stainless steel (mainly the 300 series) permits the recovery of other valuable elements, such as molybdenum in the popular 316 grades. The only occasional exception is "mixed turnings and borings," which sometimes contain not only various stainless grades but also alloy and carbon steel and perhaps even some free cutting brass. Here there is a problem of identification as well as contamination. A rail car or truck of such material is a heterogeneous mix that is difficult to sample in a statistically acceptable fashion. One approach that has been adopted is to crush and blend the scrap; the resulting product can be sampled and meaningfully certified and shipped as such or blended to customer specifications . Based on discussions with scrap dealers and melters, turnings represent less than 25 percent of the total amount of prompt industrial scrap, and at least three-quarters of the turnings are clean enough to be recycled to the stainless steel melting furnace. This leaves less than 14,000 tons of poten- tially poor quality turnings; some may be exported, but most such turnings appear to be recycled domestically as part of the iron and carbon steel scrap amounting to approximately 45 million tons a year. With the exception of these turnings, nearly all prompt industrial stainless steel scrap is recycled within a relatively short time (less than a few years) after generation. 26 0.15 i Range in values 1929-38 LU o DC Hi Q. I I- X o LU 5 1980 Source: American Iron and Steel Institute Survey Data from D. Blickwede, Bethlehem Steel, Bethlehem, Pa. FIGURE 4. - Residual elements in carbon steel manu- factured in the United States. Downgrading Figure 4 shows that the chromium content of carbon steel produced in the United States for the past several decades has been about 0.05 ± 0.01 percent. Thus, one would expect that carbon steel scrap would have a similar chromium content when goods are discarded at the end of their lives. However, table 12 shows the chromium content of pur- chased carbon steel scrap to contain an estimated 0.12 percent chromium. Thus, the estimated chromium picked up by the 32,149,000 tons of purchased carbon steel scrap being recycled is about 22,500 tons of contained chromium [32,149,000 (0.12 - 0.05)/100]. Assuming the chromium comes from stain- less steel scrap containing 000 tons of stainless steel Some of this con- 16.7 percent chromium, it is calculated that 135 scrap was unintentionally mixed with carbon steel scrap. tamination may be due to the prompt industrial stainless steel turnings (up to 14,000 tons) discussed earlier, but the major source of this contamination appears to be obsolete scrap . In addition, figure 4 shows that the residual chromium in steel manufac- tured in the United States has risen from about 0.04 to 0.05 percent in the 1950' s and early 1960 's to about 0.06 percent in 1977. This amounts to an increase of about 0.001 percent per year. If the increase is attributed to chromium contamination from stainless steel scrap, which seems likely, the amount of stainless steel downgraded can be estimated by assuming an average total steel production of about 120 million tons per year, which when multi- plied by 0.001/100 amounts to 1,200 tons of contained chromium, or about 7,000 tons of stainless steel assuming it contains the average 16.7 percent chromium. Upon adding these 7,000 tons to the 135,000 tons found above, we calculate that about 142,000 tons of stainless steel may be downgraded to carbon steel scrap; of this, up to 14,000 tons may arise from prompt indus- trial stainless steel turnings, and the difference is estimated to be obsolete scrap . 27 TABLE 12 . - Chromium in purchased carbon steel scrap in 1977 Scrap grade Receipt of scrap by melters from brokers, dealers, and other outside sources, thousand tons Average chromium content , percent Total chromium content, tons Low-phosphorus plates and punchings 1,810 1,891 5,953 2,178 6,181 2,315 147 206 1,933 1,505 2,694 1,910 3,426 0.06 .09 .10 .18 .07 .19 .09 .05 .40 .03 .20 .03 .12 1,086 1,702 5,953 3,920 No . 1 and electric furnace bundles . No . 2 and other bundles Electric furnace, 1 foot and under. Slag scrap (Fe content 70 percent) . 4,327 4,167 132 103 7,732 451 5,398 573 4,111 32,149 NAp 39,655 NAp Not applicable. Obsolete Scrap Collection As already Small household the mainstream o Based on discuss stainless steel never recovered; stainless valves indicated, not all obsolete scrap generated is collected, items such as cutlery, flatware, and toasters usually join f municipal solid waste and are generally not recovered, ions with recyclers, we estimate that possibly half of the used in underground mining and drilling for oil and gas is stainless steel screws, decorative trim on buildings, and and fittings are not normally recovered. Estimates based on discussions with recyclers indicate that about 80 per- cent of all junked automobiles are collected; the remaining 20 percent are abandoned in backyards or remote sites. However, between 10 and 20 percent of the collected junked automobiles are baled with only the wheel covers and hubcaps recovered. Shredders do a slightly better job at recovering the stainless steel. However, since the 400-series fraction is magnetic, it is lost with the fragmented steel portion, which is the reason shredded steel (automotive) scrap has about 0.2 percent chromium versus the carbon-steel scrap average of 0.12 percent chromium. The nonferrous (nonmagnetic) stream is sent to a metal recovery plant from about 75 percent of domestic shredding operations; the other 25 percent apparently send the nonmagnetic stream to landfill operations. A multistage, sink-float process produces fractions con- taining mainly light organics, heavy rubber and plastics, aluminum, and heavier nonmagnetic metals like stainless steel, zinc, and copper. A rotary furnace melts and separates the zinc, and the stainless steel is separated from the copper with varying degrees of efficiency by hand picking. The cop- per goes to refineries; the stainless steel, which contains about 2 percent copper and other contaminants and is recovered with about an 80 percent 28 efficiency, is sold to a stainless steel melter. Overall, this gives a recovery factor for stainless steel in automobiles of about 30 to 40 percent. Based upon these rather subjective opinions, table 13 was developed in an attempt to quantify and reconcile the apparent large quantity of obsolete scrap from which chromium is not recovered. The largest single sector showing unrecovered stainless steel scrap is the automotive sector, followed by the appliances, utensils and cutlery sector. TABLE 13 . - Estimated obsolete stainless steel scrap recovered in 1977 Market classifications Forgings Industrial fasteners Construction, including maintenance Contractors ' products Automotive. . Rail transportation Shipbuilding and marine equipment . . Aircraft and aerospace Oil and gas industry Mining, quarrying, and lumbering... Agricultural , Machinery, industrial equipment, and tools Electrical equipment Appliances, utensils, and cutlery.. Other domestic and commercial equipment Container, packing and shipping materials Ordnance and other military Total NAp Not applicable. Downgraded or unrecovered . Estimated total obsolete scrap generation, thousand tons 7 21 18 26 241 4 5 24 1 2 2 114 28 103 35 4 13 648 Obsolete scrap generated that is ;recycled for recovery of Cr Percent 60-80 20-50 20-60 20-70 30-40 60-80 60-80 50-80 40-60 40-60 40-60 50-70 40-60 10-30 10-30 60-80 10-30 NAp Thousand tons 4-6 4-10 4-11 5-18 72-96 2-3 3-4 12-19 0-1 1-1 1-1 57-80 11-17 10-31 4-11 2-3 1-4 193-316 Obsolete scrap unrecycled for Cr recovery, thousand tons 1-3 11-17 7-14 8-21 145-169 1-2 1-2 5-12 0-1 1-1 1-1 34-57 11-17 72-93 24-31 1-2 9-12 332-455 Source: Arthur D. Little, Inc., estimates. Reconciliation Reported receipts and exports of prompt industrial and obsolete stainless steel scrap are about 492,000 tons as indicated in table 14. Such a value falls within the calculated range of 392,000 to 515,000 tons of stainless steel recovered for recycling of chromium values. Based on the 492,000 tons as a "best estimate" for stainless steel scrap recovered for chromium values, one concludes from table 14 that stainless steel which is unrecovered or downgraded amounts to 369,000 tons, of which an estimated 142,000 tons was downgraded and 227,000 tons went unrecovered. Based on an average chromium content of 16.7 percent in the 369,000 tons, 62,000 tons of chromium went unrecovered in 1977. 29 TABLE 14 . - Reconciliation of reported values with calculated values of stainless steel scrap, recovered for chromium values in 1977 (thousand tons) Source of data Unrecovered Downgraded Recovered for recycling of Cr Total generated As determined by this study: Nil 3 204-327 1 1A 128 2 199 193-316 213 648 Total 204-327 NA 227 142 NA 142 392-515 H92 492 861 Reported receipts by melters and net exports of prompt industrial NA "Best estimate" used in further 861 NA Not available. 1 Estimated to be no greater than 14. ^Calculated by the difference between 14 and 213 . Calculated by the difference between columns (2 + 3) and 4. ^Errors in estimating imports may add up to 58,000 tons of the 492,000 tons shown (see text) . Source: Arthur D. Little, Inc., estimates. Estimates of Potential Error Scrap Imports As discussed in the section on scrap collection and foreign trade, a likely value for stainless steel scrap imports was 7,000 tons in 1977, but the value could be as high as 66,000 tons. If scrap imports are increased by 59,000 tons, it would increase uncollected domestic scrap by a like amount. Yields in Manufacture The magnitude of other potential errors can be best evaluated from an examination of equation 9 for uncollected scrap: U < D " Y av D ) 7 7 + < Y avD) t " S 77 (9b) Substituting apparent domestic consumption of steel mill products (D) for the years 1977 and the year (t) (t = T in equation 4b) into equation 9 and assum- ing an average yield in manufacturing invariant with time: U = A + 77B - Y (A + 77B) + Y av (A + 64B) = A + 77B - Y B (77 - t) - S 7 _ av 77 7 7 (14) 30 The parameters A and B have been determined from a linear regression equation for apparent domestic consumption and are treated as constants. Domestic shipments account for more than 90 percent of apparent domestic consumption. Thus, we believe that little accuracy is lost by lack of net import data on stainless steel mill products before 1964. From appendix B we see that the average calculated yield, Y , ranges from 0.80 to 0.83 in the years 1957 to 1977. Some industry respondents have expressed the belief that such a value is of the right order of magnitude, while others have expressed alternative views indicating a range in opinion that Y av - 0.8 may be off by ±0.1. Recognizing that parameter B has a value of 27.24 (thousand tons per year) and t of about 64 (see appendix D) , the impact on U is given as a change in U, or AU: AU = B(77-t) AY av = (27.24) (77-64) (0.1) = 35,000 tons of uncollected stainless steel scrap. (15) When compared with our "best value" of 369,000 tons of unrecovered (or downgraded) stainless steel scrap., it seems that the potential error in yield values would impact our results by under 10 percent. Prompt Industrial Scrap Generation Although most of the yield loss in manufacturing goods from steel mill products can be accounted for by scrap, discussions with manufacturers indi- cate there are other losses such as grinding swarf which might amount to a few percent (at most) of consumption. If it is assumed that a loss rate of 2 per- cent can be applied to all steel mill shipments in 1977 (1,120,000 tons), it is calculated that such losses may be 22,000 tons. This would reduce prompt industrial scrap generation and total uncollected scrap by a like amount. Average Lifetimes While few industry sources have questioned the lifetime estimates for short-lived goods containing stainless steel (those having lives of 10 years or so) , a few contacts have expressed some concern about the long-lived prod- ucts (goods having lives of about 20 years) . Basically these contacts feel that some stainless steel goods in the market classifications shown in table 7 would last more than 20 years. Thus, they suspect the average year for manu- facturing such long-lived goods was some time prior to 1957 if the goods were discarded in 1977. Opinions expressed exhibit an upper limit to average life cycles in the long-lived product category of 25 years; in other words, long- lived stainless steel goods were allotted a range of lives from 15 to 35 years. The impact of such an assumption is estimated as follows: 31 If they appeared as obsolete scrap in 1977, goods with 25-year aver- age lives were manufactured in 1952. From equation 12, estimated apparent domestic consumption of stainless steel mill products was 465,000 tons in 1952. Based on an average yield from steel mill products to manufactured goods of 0.8 (appendix B) , stainless steel entering consumer goods in 1952 amounted to 372,000 tons (465 x 0.8). As a result the total tons of stainless steel in the column labeled "1957" of table 6 would be adjusted downward from 492,143 to about 372,000 tons, or a reduction of 24 percent. A similar downward adjustment of 24 percent would be made in table 7 for "long-lived goods" which would reduce obsolete scrap generation as well as total scrap generation (G) by 31,000 tons (rounded from 128,757 x 0.24). As seen in equation 9, uncollected stainless steel scrap in 1977 would be reduced by a similar amount. Thus, a 5-year increase in the average lifetime of the long-lived goods would reduce uncollected scrap (U) in 1977 by 31,000 net tons. Imports and Exports of Manufactured Goods Obviously imported goods containing stainless steel that are manufactured abroad, such as automobiles, contribute to obsolete scrap generation. If goods manufactured domestically are exported, such goods would typically not add to domestic obsolete scrap generation at the end of the products' lives. Imports and exports of manufactured goods containing stainless steel have been neglected in this study. Because data were unavailable on the amount of stainless steel in manufactured goods that are exported or imported it is impossible to quantify any potential errors that may occur by neglecting such exports and imports. However, except in a few instances (for example, auto- mobiles, utensils, machinery) imports or exports containing large amounts of stainless steel have not been identified. Based on industry contacts, it is estimated that manufactured goods exported or imported would be well under 20 percent and more likely under 10 percent. The impact of a 10-percent increase in imports of manufactured goods containing stainless steel would increase obsolete scrap generation by a like amount. Since obsolete scrap generation is estimated to be 648,000 tons (table 8), a 10-percent increase in imports would add about 65,000 tons to uncollected domestic scrap. Corrosion Losses resulting from corrosion, erosion, and general wear are extremely difficult to estimate, and no data have been found with regard to stainless steel on which to base a calculation. In an earlier study, Nathan Associ- ates (8-9) estimated that uncollected carbon steel scrap in inventory corrodes by about 0.36 percent per year. Stainless steel is expected to corrode less, but is is not known how much less. In addition, we have seen no estimates of erosion and wear of stainless steel parts in service. If a 1-percent annual loss rate resulting from corrosion, erosion, general wear, etc., is accepted, this would amount to about 10,000 tons annually (that is, 1 percent of approxi- mately 1 million tons of stainless steel scrap used in manufactured goods) . However, it should be recognized that such a calculation is based on almost no data and could be subject to a potentially large error. 32 Superalloy Downgrading As discussed, some chromium losses occur by downgrading of stainless steel scrap to carbon steel. In a prior study (5) an opinion gathered by discussions with superalloy dealers indicated that downgrading of superalloys to stainless steel scrap also occurs, but only rarely. Based on these discus- sions, it is estimated that such downgrading amounted to less than 10,000 tons of superalloys, with average chromium contents in the same range as in stain- less steels. This has the effect of increasing uncollected stainless steel scrap by up to 10,000 tons. Allocation of Steel Mill Products Although it is believed that the methodology (involving allocation of semifinished steel mill products, shipments to service centers, net imports, etc., to other categories) leads to only small potential errors in determining scrap generation, this procedure may involve significantly larger potential errors in determining the relative importance of one market classification as opposed to another in terms of uncollected scrap. Examination of tables 3 and 4 shows that the largest unknown involves shipments by steel service centers, which account for about 35 to 40 percent of apparent domestic con- sumption of stainless steel. Clearly, better data are needed on shipments by steel service centers before doubts on the relative amounts of stainless steel shipments to different sectors of the economy can be eliminated. Future Work The potential errors in the factors leading to estimates in (U) (unre- cycled or unrecovered scrap) are compared in table 15. It is seen that poten- tial errors can be up to 10 to 20 percent of the estimated 369,000 tons of uncollected scrap and that the most significant factors are — 1. Neglecting imports and exports of manufactured goods containing stainless steel. 2. Estimating stainless steel scrap imports. 3. Estimating scrap losses in manufacturing. 4. Lifetime estimates for long-lived goods containing stainless steel. Obviously if the price of chromium rises substantially, a larger fraction of chromium scrap generated would be expected to be collected. The effect of chromium prices on chromium scrap recycling has not been analyzed in this study. Outside of the category of erosion, corrosion, etc., where little data is available, the other factors examined appear to add only a small contribution to unrecovered chromium. 33 TABLE 15 . - Potential error summary 1 (thousand tons) Potential error summary (AU equation 15) Change in uncollected scrap (U) 10-percent increase or decrease of net imports of manufactured goods Imports of scrap (limits in range) Potential errors in yield losses to scrap (1 - Y v ) in manufacturing operations Increase in life cycle of "long-lived" goods containing stainless steel by 5 years Prompt industrial scrap yield losses to scrap reduced by 2 percent and other losses (for example, grinding swarf increased by 2 percent) 1-percent annual loss rate resulting from erosion, corrosion, etc Downgrading of superalloys to stainless steel Downgrading stainless steel to carbon steel scrap •'■Base case summary for 1977: Generated (table 8) Collected (table 11) Uncollected or downgraded (U) . . 861 492 369 Projections Using equation 9b, projections can be made based on historical consump- tion patterns. Substituting the relationship for apparent domestic consump- tion of stainless steel (equation 4b) in the future year T' (expressed, for example, as T 83, '90, and so on) and in the year t, U=A+BT'-Y B (T*-t) 77 (16) Recognizing that T'-t is the life cycle for goods containing stainless steel, or about 13 years (appendix D) , and that Y av - 0.82 (appendix B) , B = 27.24, and A = -951.3 (see equation 12), equation 16 yields these values: U = -951.3 + 27.24 T' - 0.82 (27.24) (13) - S T , = 27.24T 1 - 1,241.68 - S T , (17a) (17b) v^ s/ scrap generation scrap collection Based on this equation, stainless steel scrap generation in 1977 was 856,000 tons (27.24 x 77 - 1,241.68), compared with 861,000 tons as shown in table 8. The difference is largely due to using reported data in table 8 as a basis for determining apparent domestic consumption in 1977 rather than a value calculated by linear regression for 1977 using equation 4b. Table 15 34 shows that in 1977 scrap recovered (492,000 tons) amounts to 57 percent of the 861,000 tons generated [S = 0.57G = 0.57 (27.24T - 1,241.68)]. If this same ratio holds in future years, S T » = 0.57 (27.24T 1 - 1,241.68). (18) l,DUU 1,400 1,300 1,200 - "% &<** a# S 1,100 *? 1,000 z o 1- 900 < C/> 3 o X 1- 800 700 600 - 500 400 300 200 100 n I I 1975 FIGURE 5. - 1980 1985 1990 Trendline projections of apparent domestic consumption and uncollected and downgrad- ed stainless steel scrap. Substituting equation 18 into equation 17b yields the uncollected scrap in the year T ' : U = 11.71T' - 533.92. (19) Equations 12 and 19 are plotted in figure 5 showing that the trendline projec- tion to 1990 indicates apparent domestic consump- tion of 1,500,000 tons and uncollected or downgraded stainless steel scrap of 520,000 tons. The most significant factor that may impact the amount of stainless steel recycled in the mid-1980' s and later is believed to be the degree of recycling of automobile catalytic con- vertor shells made from type 409 stainless steel. If removed from junk auto- mobiles to recover the cata-. lyst, the shells may well be segregated for recycling. If not removed, this 409 stainless steel would largely report to the magne- tic fraction in a shredding operation, which would hin- der subsequent recovery for chromium values. Industry contacts indicate that the convertor shell weighs about 35 pounds and that there may be other ways of meeting emission control laws. Nevertheless, if we assume that all U.S. -made auto- mobiles (about 10 million 35 cars a year) will have a 35-pound stainless steel convertor shell, about 175,000 tons of junk convertor shells can be expected annually in the 1990 f s (assuming the shell lasts the life of the automobile). Clearly, this repre- sents a significant source of chromium. SUMMARY This study focused on estimating uncollected stainless steel scrap. Home scrap is largely recycled and thus was not in the scope of this study. Figure 6 summarizes flows of stainless steel products and scrap as deter- mined from this study. Uncollected scrap was calculated as the difference between domestic stainless steel scrap collected (as reported by the Bureau of Mines) and the scrap generated. Estimates of prompt industrial scrap gener- ated were obtained from apparent domestic consumption of steel mill products . It was found that nearly all prompt stainless steel industrial scrap generated is collected. Obsolete scrap generation calculations were made by estimating product lifetimes and the quantity of stainless steel used to manufacture the product. It was found that most of the stainless steel scrap that is unrecov- ered arises from obsolete scrap. As shown in figure 6, about one-third of the obsolete scrap appears to go unrecovered. It is suspected, but not substantiated, that most of this unre- covered scrap arises from stainless steel used in appliances, utensils, and cutlery. Of the estimated 421,000 tons of obsolete scrap recovered, it is esti- mated that 142,000 tons are downgraded or unintentionally mixed with carbon- steel scrap. Most of this loss of chromium values apparently arises from junk automobiles. Addition of this 142,000 tons downgraded to 227,000 tons unre- covered yields 369,000 tons of stainless steel unrecovered and downgraded. Overall, figure 6 shows that about three-quarters of the obsolete and prompt industrial stainless steel scrap generated is recycled, but not always for chromium recovery. Chromium values lost in 1977, assuming 16.7-percent chromium in stainless steel, are estimated to be 62,000 tons (369 x 0.167). Trendline projections to 1990 indicate that the uncollected and downgraded stainless steel fraction can be expected to rise to 520,000 tons with about 87,000 tons of contained chromium. A major unknown involves estimating the amount of automotive catalytic convertor shells (made largely of the magnetic 409 stainless steel grade) that will be recycled. Major data gaps identified in this study that can affect the above con- clusions by 10 percent or more on the amount of stainless steel scrap uncol- lected include (1) stainless steel contained in imports and exports of manu- factured goods, (2) imports of stainless steel scrap, (3) estimates in yield losses to scrap in the manufacture of stainless steel goods from mill products, and (4) lifetime estimates of long-lived stainless steel goods. Better data are needed in these sectors to quantify more definitively the amount of uncollected stainless steel scrap. In addition, it would appear worthwhile to examine whether there are any technological problems in recycling catalytic convertor shells from junk automobiles. 36 Imports of stainless steel scrap, 7 Carbon steel scrap and other materials er Stainless steel making (melters) Raw steel, 1,860 ET Domestic receipts of stainless steel scrap, 424 Home scrap Stainless steel forming Exports Net imports of stainless steel mill ~ products, 108 I Imports 1 Domestic shipments of steel mill products, 1,118 Apparent domestic consumption of steel mill products, 1,226 Domestic steel service centers R Consumed by domestic fabricators and manufacturers, 1,204 Apparent domestic consumption of manufactured products, 1,013 ^ ET I Prompt industrial stainless steel scrap, 213 Stainless steel scrap exports. 75 492 Recyclers Domestic consumers inventory of goods Stainless steel product flow lines (semi-finished, finished, and consumer goods) Stainless steel scrap flow lines Obsolete scrap - generation, 648 Obsolete stainless steel scrap recovered, 421 Downgraded to carbon steel scrap 142 Uncollected obsolete stainless steel scrap, 227 142 Total 369 FIGURE 6. - Estimated flow of stainless steel products and stainless steel scrap between producers and consumers in 1977; numbers show estimated flows in thousand net tons of stainless steel. 37 REFERENCES 1. American Iron and Steel Institute. Annual Statistical Reports (sections on raw steel production and shipments — steel products) . Washington, D.C., 1957-77. 2. American Metal Market Co. Steel. Ch. in Metal Statistics (published annually). Fairchild Publications, New York, 1957-77. 3. Curwick, L. R., W. A. Petersen, and H. V. Makar. Availability of Criti- cal Scrap Metals Containing Chromium in the United States. Superalloys and Cast Heat- and Corrosion-Resistant Alloys. BuMines IC 8821, 1980. 4. Institute of Scrap Iron and Steel, Inc. Specifications for Iron and Steel Scrap. Washington, D.C., 1975, pp. 13-16. 5. Kusik, C. L., and C. B. Kenahan. Energy Use Patterns for Metal Recycling. BuMines IC 8781, 1978, pp. 112-124. 6. McGannon, H. E. (ed.). The Making, Shaping and Treating of Steel. United States Steel Corporation, Pittsburgh, Pa., 9th ed., 1971, pp. 1163-1202. 7. Parker, E. R. (Committee Chairman). Contingency Plans for Chromium Utilization. National Materials Advisory Board, National Research Council, National Academy of Sciences, Washington, D.C., 1978, 374 pp. 8. Phoenix Quarterly. Potential Scrap Harvest Grows. V. 10, No. 3, Fall 1978, p. 3. 9. Robert R. Nathan Associates, Inc. Iron and St^el Scrap — Its Accumulation and Availability. Washington, D.C., 1977, pp. 78-80. 10. Shonka, D. B., A. S. Loebl, and P. D. Patterson. Transportation Energy Data Book. Oak Ridge National Laboratory, Report ORNL-5320, 2d ed., 1977, 567 pp. 11. Teplitz, B. (ed) . American Metal Market. Nickel Stainless Supplement. Fairchild Publications, New York, Nov. 10, 1978, p. 20. (Export data are credited to Institute of Scrap Iron and Steel.) 12. U.S. Bureau of the Census. Steel Mill Products. Current Industrial Reports, 1977, pp. 18-21 (table 11). 13. U.S. Bureau of Mines. Iron and Steel Scrap. Mineral Industry Surveys, Monthly, 1957-77. 14. U.S. Department of Commerce. U.S. Imports for Consumption. Document FT246, 1977, p. 273. 38 APPENDIX A. —BACKGROUND Stainless Steel Types and Chromium Content Most grades of stainless steel have been classified by the American Iron and Steel Institute into three broad series — 300, 400, and 200: 300 Series — The nonmagnetic 300 series (table A-l) is the most widely used form of stainless steel. The 18-8 alloys (referring to their chromium and nickel content, respectively) belong to this series. Besides chromium and nickel, other elements may be present in varying proportions, such as molyb- denum in grades 316 and 317, and columbium in grade 347. This series of alloys is used in a great variety of applications in the construction indus- try, kitchen utensils, hospital equipment, chemical plants, refineries, and the aerospace industry. 400 Series — The 400 series (tables A-2 and A-3) is magnetic and consists of straight-chrome grades of stainless steel containing 10 to 27 percent chromium. This series of alloys contains various amounts of minor additions but little or no nickel . Some grades are f erritic (very low carbon) , while others are martensitic. This series has a variety of uses, such as for decorative purposes, cutlery, automobile mufflers, and heat exchangers. Type 409 stainless steel is used exclusively for automobile catalytic con- vertor shells; its production is exceeded only by the all-purpose nickel- chromium 304 grades. 200 Series — The less common 200 series (table A-l) is nonmagnetic. In this series, manganese is partially substituted for nickel in order to retain the austenitic structure, resulting in a composition containing 3.6 percent nickel, 16 to 20 percent chromium, and 5 to 10 percent manganese. Annual stainless steel production by AISI number can be found in Metal Statistics (2_) . 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D P a 5- cc •H c 4J Ct H rH 'H CO H 4J U E ^ 5- ct p C •H 4- •r H CO ct U r- •H CU toO pi CU CO 4J C rH P - c •r- •r- 43 C r- QJ 4J c O C CU >-l Tj QJ Pi Pi 4- •H »H r- r- P r- O a P u,a Pi 13 PU P 4J 4J o d 4-1 O O 3 CO JP •Pi •i- •r- 61 D CO H P U 4-1 O u * C QJ CO Pn H CO u u < c2 CO < c X < >gH H < o o o w £ 3 •H e rH QJ QJ 4J CD 13 QJ 43 CO •H d •H m o 4J CO 4-1 CJ pi 13 o u Pu 13 QJ Xi CO •H d •H m • •H CD s QJ CU 4-> CO CO 6 M-4 •H o 4-1 CO d 0) o •H #1 CO • Vl CJ QJ d > H d o n CJ QJ rH 6 4-1 o 4J u •H IH rJ Pi- • co o u o v< CD pi 43 rH 4-t CO Vi •H cO TJ d rH •H | C_> 4J & QJ 6 rH o 42 u • cO PU CO H 4J co o QJ PJ • • 13 13 CO PJ O QJ rH >-l CJ U PU u X PJ H O — i CO 50 APPENDIX D. —AVERAGE AGE OF OBSOLETE GOODS About 648,000 tons of obsolete scrap was generated in 1977 (table 7). The average year (t) in which goods were manufactured that appeared as obso- lete scrap in 1977 can be calculated, recognizing that the average yield (Y ) from stainless steel mill products to manufactured goods is about 81 percent between 1957 and 1967 (appendix B) . Thus, apparent domestic consumption (D t ) in the year (t) was about 800,000 tons of stainless steel mill products (648/0.81). Substituting D t = 800 into equation 12 and solving, we find T = 64.3; thus, the average year (t) in which the goods containing stainless steel were manufactured is about 1964. 51 APPENDIX E. —OBSOLETE AND PROMPT INDUSTRIAL SCRAP COLLECTED Stainless steel scrap data for 1977 of interest to this study were pub- lished by the Bureau of Mines in the May 1978 Mineral Industry Surveys of Iron and Steel Scrap ( 13 ) . Companies reporting scrap shipments are "manufac- turers of pig iron and steel ingots and castings," which are labeled as "Melters" in this study. Receipts of scrap by melters from "brokers, dealers, and other outside sources" reported by the Bureau of Mines totaled 424,000 tons in 1977. These receipts are thought to be largely purchased scrap according to the Bureau of Mines staff, and thus are included in the category of prompt industrial and obsolete scrap. The Bureau of Mines also reports receipts of stainless steel scrap "from other own company plants" as well as shipments by melters, which are not considered new supply. These receipts roughly balance reported shipments, with each amounting to about 10 to 15 per- cent of receipts from brokers, dealers, etc. Receipts and shipments are largely intercompany transfers of scrap between steel mills. Since scrap generated within steel mills is not considered in the scope of this study, it has been excluded from the estimates. In short, prompt industrial and obsolete scrap collection is estimated to be 424,000 tons in 1977. „ „ „ INT.-BU.OF MINES, PGH..P A. 24693 U.S. GOVERNMENT PRINTING OFFICE : 1980 - 325-969 o ..■„.- o- ,V ,=>^ r <^ ^ ^0* ^0• & v \1^L'* c- a? •L*°- > V •l^L'* «v aP v • '•„ ••»'- W -ife *W •«'•- V •» <> *<7V ^n< V .LVL'«, c\ **0« >°-v ^ V ■* n A» .j «- A* .% r> * ^. ,** ^. ** v \ '-.1 •*v ^ K ~JPM$?^\ v~ 0, nK. v «*o« r oV" fe^ ^ - , .'^fc.-, ^/ ,^,_ ^ ..|j|, ^/ ,^,_ ^ : |||v, \jf ..| . .* A ^> / *\^fc \ ^$$&S /^ y ^c\ ^J^^r /^^-% ,0 V »!*•-*> V N ♦''XL'* c\ ,0 V •!'•- > V % ♦l^L'* C^ ,0 V •!*•- ^ V »• V*s^>" V'^ 4 '^ ^-sfffrV' '^°"?.^ ; V* \ •- «^ A* »Jf *• ^ «, ^ SlO" , » • • ^ .-1^ **o* ♦ o ,«■ •♦TV?' . v^ ' • ■ ° ^ t O %TT« •_ >~ c^ * *,/ ^^^^ v^*y %^\* \ ^^ N. MANCHESTER, sa = # ^ INDIANA 4fiPK9 .A i* - "♦ * .0 V ■: