ILLINOIS J&md ofXtitcofo \ CIRCULAR 201 ILLINOIS STATE GEOLOGICAL SURVEY URBAN A 4&&W ^7==^ 557 I 6c no. 202 STATE OF ILLINOIS WILLIAM G. STRATTON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION VERA M. BINKS, Director DIVISION OF THE STATE GEOLOGICAL SURVEY JOHN C. FRYE, Chief URBANA CIRCULAR 202 SIZING STUDIES ON PILOT-OVEN COKE COMPARISON WITH COMMERCIAL COKE SIZE BY H.W. JACKMAN and R.L. EISSLER PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS URBANA, ILLINOIS 19 5 5 ILLINOIS GEOLOGICAL SURVEY LIBRARY SEP 28 1QW Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/sizingstudiesonp202jack SIZING STUDIES ON PILOT- OVEN COKE COMPARISON WITH COMMERCIAL COKE SIZE by H. W. Jackman and R. L. Eissler ABSTRACT Coke produced in a pilot oven of commercial width may be made to compare closely in size with commercial -oven coke. Mul- tiple drops from the shatter box cause breakage of the larger pieces, corresponding to the size degradation in plant equipment. Three drops of six feet each approximate average plant handling, but the procedure must be checked and adjusted for accurate comparison with any individual operating plant. Tumbler indices are not affect- ed appreciably by this procedure and compare closely with plant practice. Coke produced in the pilot- size coke ovens at the Illinois State Geo- logical Survey compares closely with commercial coke in strength charac- teristics as measured by the standard A.S.T.M. tumbler test. Pilot-oven coke tends to be larger than the commercial product, however, owing to less breakage of the coke during removal from the oven and subsequent handling. Breakage in a commercial coke plant starts as the coke is pushed from the ovens and falls ten feet or more into a hot car. After quenching, it is dumped onto a wharf, slides through gates onto a moving belt, and is con- veyed to the screening plant. After screening,the coke is usually dropped into hoppers or storage piles and later transferred to skip buckets or belts for movement to final destination. Each drop or movement produces break- age, which results in a smaller size consist. In comparison, pilot-oven coke falls a distance of from one to four feet when pushed into the quenching car. It is shoveled into drying pans and later removed, but no other handling is required before the coke is screened. DEVELOPMENT OF A METHOD FOR SIMULATING COMMERCIAL COKE SIZE Both the size and strength of pilot- oven coke should simulate the prop erties of the commercial product if test-oven results are to be of maximum value. Therefore, the pilot ovens have been operated at commercial coking rates and coke temperatures. It quickly became apparent, however, that ow- ing to insufficient handling, the pilot-oven coke was large. To correct this condition, we dropped the coke made in the 14-inch pilot oven (Reed, 1947) a distance of 6 feet from the shatter box before screening and sizing. The size [i] cons IL LINOIS STATE GEOLOGICAL SURVEY onsist of duplicate ^^ZZ^~£2F£ ^ ; "- rtLS£^=55^ tLl — cial coke ' however> and there was a smaller percentage **»*'■ inches wide was Wt ^^ ^ l \lT£XZZm TTon OVI in g previous practice, this in our ^° rat0 7 d in at 1 ^ c 3 S: k r ™t 'of one inch per hour. The resulting coke, oven was °P* rated /, a fo ™ _ from the shatter box, was considerably larger even after the »-£ 6 q ^? inch oven . Table 1 gives comparison of the S r sTrtgtn rartt^rlstics of co.es from the two pilot ovens under iden- tica! handling ™^ ^ was larger also than that made in com- The 17-inch puo width from the same blends at essentially rc ial -- ^same ave rage w ^ ^ ^ ^ ^^ ^ the same coking rate. J*? ^ be reduced to that of corresponding mi ne how *. c -e •Jg^or-o* were dropped 6 feet from the shatter box rr Q : and tee tills, and the resultant products were sized and compared the size consist of cokes made from two coal blends is shown m table 2 The ol the *< x 2" size at the center of the range may either increase or de- ^Ltdependlng on the coke being tested. The yield of furnace-size coke is reduced sUghtly by each additional drop, and there is a corresponding increase; ^ ^ y ^^.n^::::s on coke strength, - Tbe effect of multiple drop, on coke strength measurements is shown in table 3. Shatter indices are in- creased by additional preliminary handling because the most fragile pieces of iarge coke are broken before the test is made. Tumbler indices , arc .not af- fected appreciably, probably because the 3" x 2" pieces used in the tumbler drum are more stable, having been formed chiefly by breakage of larger pieces. They are not as susceptible therefore to preliminary handling as are the larger pieces that form a portion of the sample used in the shatter test Co mparison with commercial-oven coke. - Pilot-oven coke that has been dropped from the shatter box three times checks most closely in size with plant coke. Comparisons of pilot and commercial cokes from two coal blends are shown in table 4. The coke size consist was computed on the fur- nace size (+1") except for blend 2 in which the commercial furnace size is plus 1 1/4 inches. . Coal blend 1, which contained 75% Illinois coal, produced coke in tne pilot oven having approximately the same size consist and the same average size as that produced in commercial ovens. Pilot-oven coke made from coal blend 2, all Eastern coals, was somewhat larger than that produced commer- cially. To duplicate more closely the sizing of commercial coke made from SIZING STUDIES ON COKE 3 coal blend 2, our operating procedure would have to be adjusted or the coke dropped a greater distance or more than 3 times, before sizing. The strength of the coke in each series, as indicated by the tumbler test, checks within the reproducibility of the test itself. Shatter-test indices are higher, however, on the pilot-oven coke. Yields of commercial sizes of coke, based on the weight of coal charged to the ovens, check within close tol- erances. SUMMARY AND CONCLUSIONS The following conclusions have been drawn from this investigation. 1) Coke can be produced in a pilot oven 17 inches wide that compares closely in size and strength characteristics with commercial-oven coke. 2) Coke strength as measured by the tumbler test does not depend pri- marily on the width or size of the oven. Coke sizing, however, varies with oven width and with the handling received by the coke either in regular plant operation or by special treatment of the pilot-oven coke. 3) Multiple drops of the pilot-oven coke from the shatter box reduce coke size and can be used to simulate the breakage occurring when pushing coke from a commercial oven and handling it through the plant conveying and screening system. 4) Three drops of six feet each may closely simulate plant breakage. It must be understood, however, that just as coke handling varies in different plants, so the handling given pilot-oven coke must be studied and adjusted when checking size consist with an individual operating plant. REFERENCES Jackman, H. W., et al., 1955, Coke oven to measure expansion pressure - mod- ified Illinois oven: preprint of paper given at Blast Furnace, Coke Oven, and Raw Materials Conference, Philadelphia, Pa., April 1955, A.I.M.E.; reprinted as Illinois Geol. Survey Reprint Series 1955-E, 16 p. Reed, F. H., et al., 1947, Use of Illinois coal for production of metallurgical coke: Illinois Geol. Survey Bull. 71, 132 p. ILLINOIS STATE GEOLOGICAL SURVEY Table 1. - Comparison of Pilot-Oven Cokes No. of drops from shatter box Coke sizing (% of total coke) +4" 4" x 3" 3" x 2" 2" x 1" 1" x 1/2" -1/2" Average size (in.) Tumbler test Stability- Hardness Coal blend 58 1/2% 111. No. 6 (1) 21 1/2% Eagle 20% Pocahontas 14" oven 17" oven Runs 581- Run IE 584 9.3 29.7 40.3 16.2 1.5 3.0 2.73 48.3 66.1 15.2 32.3 36.4 11.8 1.1 3.2 2.92 49.6 65.1 Coal blend 55% 111. No. 6 (2) 20% 111. No. 5 25% Pocahontas 14" oven Run 589 6.6 29.5 42.8 16.4 1.7 3.0 2.67 45.6 64.0 17" oven Run 10E 17.0 27.9 37.6 13.5 1.6 2.4 2.90 44.9 63.2 Shatter test +2" +1 1/2" -1-1" 67.4 87.5 95.5 73.0 89.9 96.2 73.0 88.5 96.6 68.2 86.7 95.7 SIZING STUDIES ON COKE Table 2. - Effect of Multiple Drops on Coke Sizing Coke sizing (% of total coke) +4" 4" x 3" 3" x 2" 2 M x 1" 1/2' -1/2" Average size (in.) Coke yields (% of coal as charged) Furnace (+1") Nut (1" x 1/2") Breeze (-1/2") Coke sizing (% of total coke) +4" 4 M x 3" 3" x 2" 2" x 1" 1" x 1/2" -1/2" Average size (in.) Coke yields (% of coal as charged) Furnace (+1") Nut (1" x 1/2") Breeze (-1/2") 1 6 -ft. drop Run 38E 16.6 34.6 31.9 12.2 1.2 3.5 2.96 2.56 55% 111. No. 6 (3) 20% 111. No. 5 25% Pocahontas 2 6-ft. drops Run 37E 9.6 23.6 44.1 16.6 1.9 4.2 2.63 3 6-ft. drops Run 36E 5.3 22.2 45.7 19.8 2.5 4.5 2.49 65.3 64.6 63.6 0.8 1.3 1.7 2.4 2.9 65% Elkhorn 35% Pocahontas 3.1 1 6-ft. drop 2 6-ft. drops 3 6-ft. drops Run 53E Run 52E Run 50E 9.1 4.5 2.9 21.3 18.7 16.0 41.3 38.9 40.2 23.1 31.2 33.6 1.7 2.3 2.5 3.5 4.4 4.8 2.33 2.23 67.9 66.8 65.6 1.2 1.6 1.8 2.5 3.1 3.4 ILLINOIS STATE GEOLOGICAL SURVEY Table 3. - Effect of Multiple Drops on Coke Strength 55% 111. No. 6 (3) 20% 111. No. 5 25% Pocahontas Tumbler test Stability Hardness Shatter test +2" +1 1/2" + 1" Tumbler test Stability- Hardness Shatter test +2" +1 1/2" + 1" 1 6-ft. drop 2 6-ft. drops 3 6-ft. drops Run 38E Run 37E Run 36E 52.8 51.9 51.8 66.4 66.9 65.0 74.0 78.8 81.0 90.0 91.3 93.5 96.0 96.7 98.0 65% Elkhorn 35% Pocahontas 1 6-ft. drop 2 6-ft. drops 3 6-ft. drops Run 53E Run 52E Run 50E 51.1 52.4 52.4 71.7 71.1 70.6 59.3 69.0 67.5 84.0 87.3 88.0 95.3 96.2 96.0 SIZING STUDIES ON COKE oo Pi h T> 2 ° Pi O ^ ble oca CO -t-> 1 HP, r-H 3 ° #** CO U m m CD vD CO rf ■M Pi Ph cd "tf o m o vo o o 00 00 ^ h tn M ^t* CO* co m m nO en co fM rsj m o i-H T$< f\J «-H in I s - en rQ 3 C rt u ■a •iH 2 vO o o ^ i— I CM , vO 00 in o +■» JQ m co m i— 1 ^ — < co ,_, vO i— i cd r£ CO i-H CM CO oo" r>-* NO ^t" CM* eg r— ( *-' cd g u CO CO CM m vO vO o vO cd 1 CD i— I vO in o" o 2 £ o (d > cd •M ^ # > u . i-H r-H o Pi i-H •H cd o rt a ft CD > CO Ph s£ *£ t£ m m o m -M fM 00 sO Th vO _i ^ 00 in o m —i in cm cm o • • • • • • , i-H cm *0 vO CO 00 ■— » CM CO vO a"> r*-* CO i-H CO . 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