a survey of the coking properties of illinois...

S ~ & E OF JLLINOIS

DEPARTMENT. OF REGISTRATION AND EDUCATION

A Survey of the Coking Properties of Illinois Coals

ILLINOIS STATE GEOLOGICAL SURVEY John C. Frye, Chief URBANA

CIRCULAR 412 1967

A SURVEY OF THE COKING PROPERTIES OF ILLINOIS COALS

H. W. Jackman and R. J. Helflnsline

ABSTRACT

Illinois coa ls from a l l the mining areas and a l l the commercially mined seams in the s tate have been evaluated for their ability t o produce both chemical and metallurgical coke. They have been coked both by themselves and in blends, and i t has been found that many of these coa ls that, are not suitable for metallurgical coke because of their a sh and sulfur content might be used t o produce chemical coke where these impurities are not too critical.

INTRODUCTION

Coking studies of Illinois coals from the low-sulfur area in southern Illi- nois have been made a t the Illinois State Geological Survey since 1942. Many blends of these coa ls with high-, medium- and low-volatile eastern coa ls have been carbonized in pilot coke ovens, and the cokes have been evaluated for their use in the metallurgical industry a s fuels for blast furnaces or iron cupolas.

Metallurgical cokes, when used a s blast furnace fuel, perform three pri- mary functions. They must bum a t the tuyeres to supply reducing g a s e s in order t o convert iron ore into metallic iron; they must furnish heat to melt the iron and slag that are produced: and they must retain their s ize and shape a s they travel through the furnace shaft in order t o maintain a porous structure in the ore burden and allow the reducing gases to travel upward easi ly. In addition, metallurgical coke must contain a minimum of a sh and sulfur, a s these require additional flux- ing agent and heat for removal with the s lag. Metallurgical coke, therefore, must not only be low in these impurities but must have strength and s ize stability.

Study a l so has been made of the use of Illinois coals for the production of chemical coke-coke used in electric furnace reduction of ores or in conversion of limestone and carbon into calcium carbide. Chemical coke may have chemical and physical properties that differ from those required in the metallurgical product. Low

2 I L L I N O I S STATE G E O L O G I C A L SURVEY CIRCULAR 4 1 2

sulfur content is not necessarily a prerequisite, and although low ash content is desired, i t may not be required, if a uniform analysis can be maintained. Like- wise, the physical properties of chemical coke may vary from those of metallurgical cokes. Chemical coke i s usually crushed by the producer to a maximum s ize not exceeding 3/4-inch. Coke f ines of approximately 1/8-inch maximum size are screened out and sold separately, usually bringing a lower return than the larger s i ze s . It i s imperative, therefore, to maintain coke fines a t a minimum.

Studies have shown that a structurally weak coke (one with a low tumbler stability index) tends t o produce l e s s fines when crushed than does a strong coke (Jackman and Helfinstine, 1964). Studies a l so indicate that a brittle coke (one with a high tumbler hardness index) tends to produce less of the extremely fine coke s izes and dust . Therefore, for greatest realization, chemical coke should have low tumbler stability and high tumbler hardness indices.

Previous experience a t Survey laboratories has shown that many Illinois coals that are carbonized by themselves or in certain blends with medium- or high- volatile coals produce cokes with the above physical characteristics. Likewise, when some of these Illinois coals are blended with coals of lower volatile content, they produce strong cokes with physical properties suitable for metallurgical use. It was decided, therefore, to study coals from the various coal seams and mining districts of Illinois, coking representative coals by themselves and in blends, in order to determine their potential value for both chemcal and metallurgical uses .

Procedure

Coals from 2 1 mines, representing 7 seams and 15 counties, were sampled for these tes t s . In choosing these coals, a l l of the major coal mining areas in the s ta te , a s well a s a l l of the commercially mined seams, were included. In addition, one seam not mined commercially, but showing promise a s a coking coal, was included.

Each coal taken from a commercial mine was sampled a t the tipple in a reg- ularly prepared s ize , usually one produced in a reasonably large tonnage. A t mines equipped with washing facilities, a washed product was taken for the tes t . At a few mines, where no washed coal was produced, and where the a sh content was known to be high, the raw coal was sampled and subsequently washed in the Geo- logical Survey's pilot coal washer before testing.

Coal from the seam not mined commercially was sampled near the outcrop from a pit dug for this purpose. Although the sulfur content was higher than expected, coking t e s t s were made on this coal a s dug from the pit. The quantity of coal available was not sufficient to make coke t e s t s on a washed product in the pilot oven, although i t was found that the sulfur content could readily be reduced by washing.

In addition t o coking these Illinois coals by themselves, they were coked in blends with higher rank coals from the Appalachian area. Medium- and low-volat i le coals were used mainly for blending. The cokes produced from such blends usually were stronger and larger than those made from all-Illinois coals . When using low-sulfur Illinois coals in blends, cokes of metallurgical quality were produced.

All coking t e s t s were made in the Geological Survey's pilot coke oven, a slot-type oven. 17 inches wide, with approximately 700 pounds coal capacity (Jackman e t a l . , 1955). Cokes produced are very similar to those made in commer-

C O K I N G PROPERTIES OF I L L I N O I S COALS 3

cia1 slot-type coke ovens. Limited experience has shown that satisfactory correlations a l so can be obtained with cokes produced in rectangular nonrecov- ery ovens.

A l l cokes produced in the Survey pilot oven were sampled and analyzed for volatile matter, ash, and sulfur by ASTM standard methods of analysis. In addition, each coke was dried, sized, and tested for drop-shatter and tumbler strengths, and for apparent specific gravity, by accepted ASTM procedures. Yields of the various s izes of coke were computed, and in certain cases , crush- inq t e s t s were made on 25-pound samples of 3- by 2-inch and 2 - by l-inch s izes of coke in order t o determine the amount of minus 1/8-inch screenings obtained from a jaw crusher s e t to produce a 3/4- inch maximum s ize product. No apparent differences were noted in crushing results from these two s izes of coke, and thus results have been averaged and reported a s though 3 - by l- inch coke had been used.

Acknowledgments

We wish t o express our appreci- ation t o a l l of the Illinois coal producers who furnished coals for these t e s t s . W e a lso thank the eastern coal producers and the s teel companies in the Chicago and St. Louis areas, who furnished the coals for blending.

Figure 1 - Reglonal locations of Illinois coals tested.

EXPERIMENTAL RESULTS

for the purpose of this report, the Illinois coals tested have been divided into groups according t o the section of the s tate in which the mines are located. A map of Illinois (fig. 1 ) shows these divisions. To avoid positive identification, each mine i s listed only by coal seam plus a letter, such a s Illinois No. 6-A.

Analyses of the Illinois coals tested are given in table 1. The size desig- nations of al l Illinois coals a s sampled a lso are shown in this table. Table 2 gives the average analyses of a l l out-of-state coals used for blending. These coals are identified by their seam names.

- -

Northern 111. No. 2 6 P i t sample I l l i n o i s Ill. No. 6-A 718" x 1/4"

Moisture (%)

14.3 16.5

Moisture-free b a s i s L V o l a t i l e Fixed

mat ter carbon Ash Su l fu r

45.6 50.0 4.4 2.21 42.4 50.9 6.7 3.01

Maximum Gieseler

2 119 3 112 11

West-Central 111. No. 2-B 1 1/2" screenings 13.8 47.9 46.6 5.5 3.28 3 1/2 28,000

I l l i n o i s Ill. No. 2-C 314'' x 1/4" 12.9 43.0 51.0 6.0 3.41 4 557 Ill. No. 6-B 3" x 1 112" 12.1 44.3 45.0 10.7 4.46 3 1 /2 24

East-Central Ill. No. 6-C 1 1/2" x 1/4" 11.4 44.7 48.4 6.9 2.20 3 1/2 8,600 I l l i n o i s Ill. No. 7-A 12.0 45.2 46.0 8.8 3.11 3 112 6,000

Ill. No. 6-D Run of mine 12.7 39.3 54.2 6.5 0.89 3 Very low Southwestern F loa t 1.34 sp. g r . I l l i n o i s Ill. No. 6-E Screenings 14.0 40.0 49.5 10.5 1.88 3 1/2 4

I Ill. No. 6-F 1" x 1/4" 8.3 43.9 46.3 9.8 3.58 3 1/2 890

Ill. No. 5-A 3" x 0" 7.0 36 3 56.3 7.4 1.35 4 1/2 85 Ill. No. 5-A 1/4" x 0" 9.5 37.6 55.6 6.8 1.73 5 1/2 98 Ill. No. 5-B 1 1/4" x 1/4" 6.9 37.2 53.6 9.2 2.49 4 212 Ill. No. 5-C

{ ~ 1 ~ ~ ~ ' 1 ? 3 ~ / ~ ~ . g r . 3.9 40.7 52.6 6.7 2.43 6 24,100

Ill. No. 6-6 , 3" x Or ' 8 .1 38.7 54.2 7.1 1.16 4 1/2 50 Ill. No. 6 4 3" x 0" 9.0 36.8 55.2 7.8 0.90 3 1 1 2 30

Southern 111. No. 6 J 1/4" x 28" 8.7 37.2 55.8 7.1 1.56 3 112 20 I l l i n o i s Ill. No. 6-K 1" x 1/4" 6.8 41.4 51.1 7.5 2.79 4 112 1,110

111. Davis and 1" x 1/4" 3.8 42.0 47.1 10.9 3.44 7 6,520 Dekovan (A)

Ill. Davis and 1" x 1/4" 5.2 40.9 51.3 7.8 2.73 6 3,360 Dekovan (B)

111. Wi l l i s (Float 1" x 1/4" 1.9 36.5 57.0 6.5 2.32 6 1/2 27,000 1.35 sp. gr.)

Ill. Reynoldsburg P i t sample 3.6 40.9 54.1 5.0 2.63 5 1/2 27,500

'Analytical data by t h e Coal Analysis Laboratory.

C O K I N G PROPERTIES OF I L L I N O I S COALS 5

Coals from Northern Illinois

Two mines in the northern Illinois area were tested-one on the eastern and one on the western side of the s tate . These are both strip mines, a s the Illinois coal measures outcrop across this northern portion of the s ta te . Coals from this northern area are classif ied a s high-volatile bituminous C rank and are consistent- ly high in moisture and volatile matter. Sulfur content tends t o be high, and coking properties are poor t o medium.

Illinois No. 2-A mine mixes coals from two seams in i t s 'preparation plant. The sample was obtained, therefore, directly from the.No. 2 seam. As shown in table 1, this pit sample had a very low ash content and only a medium high sulfur content. However, the very low free-swelling index indicated weak coking proper t ies that were demonstrated subsequently when the coal was coked by itself in the pilot oven. The pilot oven coke had a very low tumbler stability index and contained a high percentage of screenings. However, a crushing t e s t on the 3 - by 1 - inch s ize coke gave favorable results, indicating possible potential use a s chemi- ca l coke. When blended withmedium- or low-volatile coals , this No. 2-A Coal produced cokes that had medium strength but a higher sulfur content than is desired for metallurgical coke.

Illinois No. 6-A, the other northern Illinois coal tested, was sampled in the 718- by 1/4-inch s i ze . It was relatively low in ash content and had somewhat stronger coking properties than the Illinois 2-A Coal. Illinois No. 6-A Coal might

High- Powellton 2.2 34.2 61.9 3.9 0.72 8 28,000 volatile

Type

Jewelld 2.4 22.5 73.7 3.8 0.74 9 1,480 Jewell-B 3.6 21.7 74.7 3.6 0.59 9 1,200

Medium- Sewell 4.0 23.5 73.4 3.1 0.67 9 2,150 volatile Splashdam 2.3 29.9 64.8 5.3 0.72 8 28,000

Pocahontas 4.0 22.0 72.6 5.4 0.58 9 950 No. 3

Beckley 2.6 18.8 75.3 5.9 0.85 9 120 Pocahontas 3.4 17.7 76.9 5.4 0.73 8 42 No. 3 4

Moisture-free basis Free-

Volatile Fixed swelling

Coal index

Low- Pocahontas 2.4 17.8 76.7 5.5 0.70 8 67 volatile No. 3-B

Pocahontas 3.8 16.4 77.8 5.8 0.79 9 24

Maximum Gieseler fluidity (dial div per min)

NO. 4 4 Pocahontas 4.1 16.9 75.5 7.6 0.69 8 23 No. 4-B

'~nalytical data by the Coal Analysis Laboratory.

6 I L L I N O I S STATE G E O L O G I C A L S U R V E Y C I R C U L A R 4 1 2

be suitable for chemical coke, a lso. When blended with sufficient medium-vola- t i le coal , the No. 6-A coke appeared t o be of metallurgical quality, except for a sulfur content of approximately 1 .5 percent. This coal did not produce strong coke when blended with the low-volatile Beckley seam, probably due In part t o i t s low fluidity. Physical and chemical properties of a l l cokes produced that contain northern Illinois coa ls are shown in tables 3 and 4 .

W L E 3 - RBsULTS OF COYMO TESTS ON ILLINOIS NO. 2 4 C M L B L m S (NORT11ERB ILLINOXS)

Date Of test: 1039-64

100% Ill. No. 2.A ( P i t ampla)

s i r e + 3"

3" r 1,' - 1"

Apparent g r a v i t y

Lb per sq i n Bulk dens i ty

( Ib per cu fr)

80% Ill. No. 2 4 20% J ~ e l l - 8

11-1044 11-12-64

C o k Physical Proper t ies

Coke Yisld (at 3% moi8rure) ( X of so.1 as rsseivsd)

60% Ill. No. 2 4 40% J W s l l - 8

C r u ~ h i s Tsar (3" r 1" cob)

Coke h1y.L. (dry)

80% 111. No. 2 4 20% Beckley

60% 111. no. 2 4 ~ e e k l e y

C O K I N G P R O P E R T I E S OF I L L I N O I S C O A L S 7

Coals from West-Central Il l inois

Il l inois No. 2 Coa l outcrops in west-central Il l inois where i t i s s t r ip mined in large tonnages. Modern washing equipment reduces a s h content t o 5 t o 6 percent . Sulfur content in the washed coa l i s high, however, and remains high i n the coke produced from i t .

I l l inois No. Z-B Coal , which was sampled for th i s t es t , proved t o be very plast ic , a s shown in table 1 . When carbonized, t h i s coa l produced considerable spongy coke, even when blended with up t o 20 percent of medium- or low-volatile coa l s . This property probably would prevent i t s succe s s fu l u se a s chemical coke, a t l e a s t without the addition of a large percentage of blending coa ls .

Illinois No. 2-12 Coal proved t o be l e s s fluid than No. 2 - 8 , and when coked by i tself , produced only a small amount of spongy coke. Jaw-crushing t e s t s indicated tha t the minus 1/8-inch screenings would be low if t h i s coke were crushed t o a 3/4-inch maximum s i ze . Blending ei ther of t he se coa l s with medium- or low- volatile coa l s produced strong cokes with low a s h but high sulfur content.

100% Ill. No. 6 d 80% Ill. No. 6 4 60% Ill. No. 6 d 80% Ill. No. 6 A 60X Ill. No. 6 4 (7/8" n 1/4") 20% J e v e l l 14 402 J e v e l l d 20% Beckley 40% Beckley

h t e of ree f : 3-5-64

k b l c r test S f a b i l i f y Hardness

S h a t t e r cear +2" +I 1/2"

s i r e +3"

3" x 1" -1"


Lb per sq i n Bulk d m r i r y

( l b per E" f e )

Pu lver iza t ion (-1/8") Coking t h e ( h r m i n )

(17" oven)

1-10-64 3-17-64

Coke Phynieal P r o p e r t i e s

coke Yield ( a t 3% m i l t u r e ) ( X rrf coal.. received)

Coke Analysis (dry)


Also tested from this area was the Illinois No. 6-B underground mine that produces a high a sh and a high sulfur product used extensively for boiler fuel. This coa l i s probably not suitable for coke because of i t s chemical analysis . As with the other coa ls from th is area, strong cokes were produced from the No. 6-8 Coal when properly blended, but the sulfur content remains high.

All of these west-central Illinois coals are classified a s high-volatile bituminous C . They are high in moisture and volatile matter and, consequently, give a low yield of coke. Results of these coking t e s t s , shown in tables 5, 6 , and 7 , indicate, however, that they may be coked either by themselves or in blends

TABLE 5 - RESULTS OF COKING TESTS ON ILLINOIS NO. 2-B COAL BLENDS (WEST-CEUTRAL ILLINOIS)

100% 111. No. 2-B 60% 111. No. 2-B ( 1 1/2" c rushed 207. J e w e l 1 4 60% Ill. No. 2-9 60% 111. No. 2-B s c r e e n i n g s ) 20% Poce. A 40% Jewell-B 40% Poca. No. 4-A

Date of t e s t :

Coke P h y s i c a l P r o p e r t i e s

Tumbler t e s t S t a b i l i t y Hardness

S h a t t e r t e s t + 2" + 1 1/2"

S i z e + 3 "

3" x 1" -1"


Coke Yie ld ( a t 32 mois tu re ) (7, of coal as received)

T o t a l coke + l" -1"

Expaneion Pressure

Lb p e r sq i n Bulk d e n s i t y

( I b p e r cu f t )

Operating Date

P u l v e r i z a t i o n (-118") Coking t ime (hr:min)

(17" oven)

Coke A n a l y s i s (dry)

V o l a t i l e m a t t e r Fixed carbon Ash S u l f u r

C O K I N G PROPERTIES O F I L L I N O I S C O A L S 9

Use of the cokes would be seriously limited, however, by their sulfur content, and, in the c a s e of No. 2-8, by formation of a spongy coke structure.

Coals from East-Central Illinois

Only a few coal mines are operated in east-central Il l inois, and no coa ls from th i s sect ion are presently used for production of coke. This is a l s o true of coa ls from the northern and west-central sect ions previously d i scussed .

Two coa ls from east-central Illinois have been coked in th i s se r ies of t e s t s . Both coa ls develop unusually high Gieseler fluidity. Both are c lass i f ied a s high-

T&BLE 6 - RPSnTS OF COKING TESTS M ILLINOIS NO. 2-C C M I BLMDS (WEST-CB6W ILLINOIS)

Lb per sq i n h l l k dens i ty

( I b per cu f t )

100% Ill. No. 2-C (3/4" x 1/4")

Coke Yleld (at 3% moisture) (% of c o a l aa received)

opera t ing Dare

81.6 86.0 1 6 5 0 16x30

Date of L e s t : 1-17-63 1-22-63 1-30-63 3-7-63 3-12-63

80% Ill. No. 2-C 20% Jewell-8

Coke Anslysia (dry)

60% Ill. No. 2-C 40% Jsvell-B

80% Ill. No. 2-C 20% Poea. No. 3-8

60% Ill. No. 2-C 40% Foes. No. 3-8

10 I L L I N O I S STATE GEOLOGICAL SURVEY CIRCULAR 4 1 2

volatile bituminous C, and both contain high percentages of moisture, volatile matter, and sulfur. These coals may be blended with medium- or high-volatile coals to produce strong cokes that have relatively high sulfur content.

The Illinois No. 6-C Coal from this area produces spongy coke when carbonized alone. For this reason, it would probably have to be blended with another coal to make a suitable chemical coke.

The other coal tested, Illinois No. 7-A, when carbonized by itself, produces a product more suitable for chemical coke. Low stability and relatively high hardness indices indicate good crushing characteristics, and this i s shown also

TABLE 7 - RESULTS OF COKIWG TESTS ON ILLINOIS NO. 6-B COAL BLENDS (WEST-CI3ITW.L ILLINOIS)

Date of t e a t :

100% Ill. No. 6-B (3" x 1 112")


Sha t t e r t e s t + 2" + 1 112"

80% Ill. No. 6-B 20% Jevell-B

s i z e +3"

3" r 1" -1"


Tota l coke +lot -1"

60% Ill. No. &B 40% Jewell-B

Lb per sq i n Bulk dens i ty

( l b per cu f t )

80% Ill. No. 6-B 20% Beckley

Pulver iza t ion (-118") Coking time (hrmln)

(17" oven)

Vola t i l e mat ter Fixed carbon Ash Sulfur

Coke Physical Proper t ies

Coke Yield ( s t 3% moisture) (% of coa l a s received)

Expansion Pressure

Operating Data

Cake Analysis (dry)

COKING PROPERTIES OF I L L I N O I S COALS 11

by the crushing test . The minus 1/8-inch screenings produced in the crusher are increased by blending this Illinois coal with coals of higher rank.

Results of coking tes ts on these east-central Illinois coals are shown in tables 8 and 9.

Coals from southwestern Illinois

Three coals from southwestern Illinois were sampled and coked. All were from the Illinois No. 6 Coal seam, and al l differed in analyses and coking prop- ertie s .

Low-sulfur coal was mined for many years in south-central Madison Coun- ty. Poor mining conditions and lack of cleaning facilities, however, caused this small mine to cease operations following World War II. Before this, it was found that although this coal had very poor coking properties by itself, it could be used a s a minor constituent of certain coal blends without detriment to the physical properties of the resulting cokes.

TABLE 8 - RESULTS OP COKING TESTS ON ILLINOIS NO. 6 2 C W BLWDS (PAST-CMTW ILLINOIS)

100% Ill. No. 6-C 80% 711. No. 6-C 60% 111. No. 6 4 80% 111. No. 6-C 60% 111. No. 6 2 (1 1/2" x 1/4'9 20% Jevell-8 40% Jevell-B 20% ~ o s a . NO, Id . 40% Poca. No. LA

Tmbler t e a t SLabiliry Hardnesr

Expansion Pramsure

0.45 0.65 50.0 51.2

Lb per sq In k l k density

(lb per eu fr)

Operating D.t.

78.4 77.8 16:30 1 6 9 0

Coke Analysis (dry)

volatile mrrer Fined earban Ash sv1f"r

12 I L L I N O I S STATE G E O L O G I C A L SURVEY C I R C U L A R 4 1 2

Coal from this location for this se r ies of t e s t s , called here Illinois No. 6-D, was obtained from the bottom of an old shaft that was sunk many years ago but never developed. An entry was driven back several feet into the coal bed t o ge t beyond any weathered coal . Samples were taken and were washed t o 6.5 percent a sh content a t the Geological Survey's laboratory. They were coked in a va- riety of blends, some of which are reported in table 10. This No. 6-D Coal de- velops practically no Gieseler fluidity and has a sulfur content of only about 0.9 percent.

A coking t e s t on 100 percent of this No. 6-D Coal yielded coke, over 50 percent of which was smaller than one inch. Attempts t o blend more than 20 per-

TABLE 9 - RESULTS OF COKING TESTS m ILLINOIS NO. 7 d C W BL?XDS (ULST-CENTW ILLINOIS)

~ u n b l s r Les t SLabLliLy mrdnells

SharLel rest + 2 " +I 112"

s i re +3"

3" x 1" -1"

~ p p a r e n t gravity

Lb per sq i n Bulk density

(lb per cu f L )

Coke Physical Properties

Coke Yield ( a t 3% moisture) ( X of "eel as received)

Expansion Preesvre

0.6 0 . 8 51.3 51 .8

operating Data

84.6 86 .1 1 6 5 0 16x30

Crushing Test (3" x 1" coke)

C O K I N G P R O P E R T I E S OF I L L I N O I S C O A L S 13

cen t of the No. 6-D Coal with other Il l inois coa l s and low-volatile Pocahontas a l l resulted in weak cokes and e x c e s s of coke f ines . However, when Pocahontas was replaced by a more fluid, medium-volatile coal , sa t isfactory coke was made when 30 t o 60 percent of the No. 6-D Coal was used. Results of t he se t e s t s are shown in table 10.

A second coal , Il l inois No. 6-E, mined in southwestern Ill inois, not far from the low-sulfur area, w a s a l s o unusually low in fluidity. This coal , a s received, had much higher a sh and sulfur contents than the No. 6-D Coal , and when carbonized by i tself , produced a normally strong chemical coke. Washing th i s coa l a t 1 . 3 3 spec i f ic gravity t o under 7 . 0 percent a s h and 1.44 percent sulfur, and coking a s before, improved the coke ana lys i s but had a detrimental effect on coke phys- i c a l properties. Because of the low fluidity of th i s No. 6-E Coal , no attempt w a s made t o coke it in blends with low-volatile Pocahontas coa l . However, when blend-

307. 111. No. 6-0 20% I l l . No. 6-0 452 111. No. 6-0 15% 111. No. 6-G 30% 111. No. 6 4 1 0 0 % 1 1 1 . N 0 . 6 - ~ 1 1 ( I

(Run of mine, 60% I l l . No. 6-I) 252 111. No. 5 4 25% Ill. No. 5 A 257. I l l . No. 5 4 1.335 ap. ax . ) 40% J w ~ 1 1 - 8 30% J ~ e l l - 8 30% J w e l l - B 25): Poca. Na. &-A

vate of t e s t : 1-16-59 3-19-59 2-6-59 lc15-59 1-22-59

volatile matter Fired carbon Ash

coke ~ h y s i e s l Properties

coke V ~ P U (nr 3% rrimturc) (2 of c a d as rsceived)

68.3 66.6 62.0 61.6 6.3 5 . 0

Coke Amlys i . (dry)


ed with medium-volatile coal , strong cokes were produced. Coking results are shown in table 11.

A third coal tested from this area in Illinois i s strip mined and designated here a s Illinois No. 6-F. It i s quite typical of coals used extensively from the Belleville area for boiler fuel. This coal has hlgh a s h and sulfur contents and medium high fluidity. When coked alone, the resulting product was probably of chemical coke quality, except for high ash and sulfur contents. Blends with medium- and low-volatile coals produced strong cokes, but their chemical analyses would prevent their metallurgical use. Table 12 shows coking results.

TMLE 11 - RESULTS OF C O W TESTS ON ILLINOIS NO. 6-8 C O U l BL?WDS (SnrmYESTEm ILLINOIS)

Date of t e s t : 10-26-62

IOOZ 111. No. 6 2 (cm8hed acreanings)

Lb per sq i n b r l k d m s i r y

(ID per EY fL)

V.1.Lile .utter fixed carbon Ash Sul fur

80% 711. No. 6-E 20% Jevell-B

Cake Phyaic.1 Proper t ies

Coke Yield (sf 3% miemre ) (X of coa l as received)

60% 111. No. b E 40% Jewell-B

Expansion Preseure

0.7 0.9 51.9 51.6

40% Ill. No. 6-8 60% Jevcll-B

100% Ill. No. 6-E (Washed sr 1.33 ap. gr.)


Coals from Southern Illinois

All of the Illinois coals commercially used to date for metallurgical and chemical coke are of high-volatile bituminous B rank and are mined in southern I1- linois from the No. 5 and No. 6 seams. No. 5 Coal is more strongly coking than No. 6; however, it i s higher in sulfur content than the NO. 6 Coal now being coked. Presently, approximately 1,600.000 tons of Illinois No. 6 Coal and 250,000 tons of Illinois No. 5 Coal are coked per year, al l of which are mined in Jefferson, Frank- lin. Williamson, and Saline Counties.

Three mines in the No. 5 seam have been tested, and the coking results are shown in tables 13 to 16. The first of these, Illinois No. 5-A Coal, i s used commercially for coke. It may be coked alone or in blends with medium- or low-volatile coals. Commercially, No. 5-A Coal in the 3- by O-inch size is used a s 20 percent of a blend containing Illinois No. 6 and low-volatile coals. Its strong

T m E 12 -RESULTS UP COKlNG TESTS ON I7JJNOIS NO. 6-F C W BLWDS (SOUTHWESTERN ILLINOIS)

m b l e r t e a t S r a b i l i r y Hardnee*

Shat te r rest +2" +1 1/2"

s i r e '3" 3" x 1"

-1"

Apparent grsvicy

1002 111. No. 6-P (1" r 1/4")

Lb per sq i n Bulk densLry

( Ib per m f r )

v o l s t i l e nstrer Fixed carbon Ash Sul fur

80% Ill. No. 6-F 20% J w e l l - 8

Coke Phyaiesl proper t ies

coke Yield (st 3% moisture) (7. a£ coal as received)

60% 111. No. 6-F 40% Jevell-B

Coke Anslyaia (dry)

80% Ill. No. 6-F 20% Beokley

60% Ill. No. 6-F 40% Beckley


coking properties and relatively high Gieseler fluidity add t o the quality of the coke produced, and i t s sulfur content of 1.4 percent or l e s s i s not objectionable in the small percentage used.

The 1/4- by 0-inch s i ze of th i s No. 5-A Coal was a l so tested and was coked by itself and blended with medium-volatile Jewel1 seam coal. Coking resul ts (table 14) are similar t o those in which the 3 - by 0-inch s ize coa l was used. Crushing t e s t s again il lustrate the relationship between tumbler stability and the amount of f ines produced in the crusher.

In addition t o the Illinois No. 5-A Coal, two others from the No. 5 seam, called here Illinois No. 5 -B and Illinois No. 5-C, were tested in this study. Both of these coa ls were coked alone and in the usual blends with medium- and low-vol- a t i l e coa l s . Illinois No. 5-8 Coal i s similar t o No. 5-A in analysis and coking properties, except for higher sulfur content. Illinois No. 5-C Coal is more near- ly like an eastern high-volatile coal, with low moisture and a very high Gieseler fluidity. Although th i s coal was high in a sh and sulfur contents when mined, i t

100% 111. No. 5 4 180% I l l . No. 5 4 160% I l l . No. 5 d 140% I l l . No. 5 4 120% I l l . No. 5 4 (3" x 0") 20% S w e l l 401. S w e l l 60% Sewell SOX S w e l l

Dare of test: 1-9-62 1-11-62 1-16-62 1-18-62 1-23-62

RMbler rest S t a b i l i t y Hardness

Shatter Lea l +2" + 1 1/2"

s i z e +3"

3" r 1" -1"

~ p p a r e n t gravi ty

Lb per a q i n Bvlk densicy

( l b per su fr)

coke ~ h y s i c a l Properties

Coke Yield ( a t 3% wi.rure) (% of coa l as received)

67.6 70.3 63.5 66 .6 4 . 1 3 . 7

v.1eti1e matter mxe* carbon Aah Sulfur

C O K I N G P R O P E R T I E S O F I L L I N O I S C O A L S 17

was washed t o l e s s than 7 percent a sh . Sulfur content remained high, however, a t 2 .4 percent. Both of these coa l s coked wel l by themselves, and both produced strong cokes with good physical properties in blends with lower volatile coa l s .

Illinois No. 6 coa l s from the southern Illinois area, which a r e used commercially i n the production of metallurgical and chemical cokes , a r e designated

TABLE 1 4 - RESULTS OF COKING TESTS ON IUINOIS NO. 5 4 COAL (I/&" r 0") BLENDS (SOUTHERN ILLINOIS)

Date of t e a t :


S h a t t e r t e s t +2" +1"

S i z e +3"

3" n 1" -1"


50% Ill. No. 5-A 50% J e w e l 1 4

T o t a l coke +1" -1"

65% Ill. No. 5 4 35% J e w e l 1 4

100% Ill. No. 5 4 (114" x 0")

Lb per sq i n Bulk d e n s i t y

( l b pe r cu f t )

80% Ill. No. 5 4 20% J e v e l l d

P u l v e r i z a t i o n (-1/8") Cokiw t ime (hr:min)

(17" oven)

, V o l a t i l e mat te r Fixed carbon Ash Su l fu r

Coke Phys ica l P r o p e r t i e s

Coke Yield ( a t 3% moisture) (% o f c o a l a s rece ived)

63.6 66.8 59.5 63.5

4.1 3.3

Expansion P r e s s u r e

Operet ina Data

Crushing T e s t (3" x 1" coke)

49.6 38.3 26.8 32.5

9.4 9 .1 14.2 20.1

Coke Analysis (dry)


here a s Illinois No. 6-G, Illinois No. 6-H, and Illinois No. 6-1. They range in sulfur content from 0.9 t o 1 . 5 percent. Blends including from 25 to 60 percent of these coals have been coked since 1944 to produce blast furnace cokes. They have been blended with high-, medium-, and low-volatile coals throughout this period, and the cokes produced have been, and continue to be, satisfactory for blast furnace use. One of these coals a l so has been used in blends t o produce chemical coke for calcium carbide production in electric arc furnaces. Pilot oven coking re- su l t s of blends of Illinois No. 6-G and Illinois No. 6-H with medium- and low-volat i le coals are shown in tables 17 and 18. Results of blending Illinois No. 6-1 with Splashdam and Powellton medium- and high-volatile coals , in order t o produce chemical cokes with relatively low tumbler s tabi l i t ies , a re shown in table 19.

One other Illinois No. 6 mine in the southern Illinois area was sampled, and the coa l was tested in the usual manner in the pilot coke oven. This coal , designated a s Illinois No. 6-K, was shown t o have satisfactory coking properties,

TABLE 15 - ReSJLT8 OF MlWG TESTS ON ILLINOIS NO. 5-8 C W BLWDS (SOUTHEIW ILLINOIS)

100% I l l . No. 5-8 80% Ill. No. 5-8 60% I l l . No. 5-8 80% I l l No 5-8 60% I l l . No. 5-8 (1 114" r 1 / 4 9 120% Jeuell-8 140% Jevell-B 120% 8 e s i l e y . I 40% Beckley ,

Date of rear: 2-13-64 2-18-64 2-20-64 2-25-64 2-27-64

Tumbler rear STabiliLy Hsrdne..

shatter t e s t +2"

Lb per mq i n m l k d m s i r y

( l b per eu f r )


Coke Yield (at 3% m i - t u r e ) (Z of coal .a received)

Coke Analyai. (dry)


both when coked by itself and in blends with medium- and low-volatile coals. It cannot be utilized for metallurgical coke under present conditions, however, because of i t s sulfur content. Results of the pilot oven tes ts are shown in table 20.

The remaining coals tested in this series of coking studies al l were taken from seams lower in geological sequence than those mentioned previously. These coals al l outcrop and are strip mined in southern Illinois. In contrast to the other Illinois coals sampled, they may be classified a s high-volatile bituminous A rank. They all have low moisture and are very plastic, having Gieseler fluidities in the range with the best eastern coking coals. They al l may be washed t o a low ash content, but, withone probable exception, they are al l high in sulfur content.

First to be tested were the Davis and Dekoven seams that outcrop and are mined in Williamson and Saline Counties. These seams are in close proximity and are mined together. Two mines were sampled. Coal from one, designated a s Illinois D&D(A), was coked by itself and was shown to have normally strong coking

~ s l e of t e s t : 1 2 3 - 6 3

Apparent gravity 0.77

Lb per *q i n 0.55 Bvlk density 48.9

(Ib per cu ft)

S Y l v e r I m t i ~ n (-1/8") 88.9 Coking Cine (hr:min) 16:30

(17" wen)

Vrrlarile utter 1.5, Fired e a r h 88.3 Ash 10.2 Svlfur 1.86

Coke Physicel Properlies

Coke Au1y.i. (dry)


properties. Coal from the other, Illinois D&D(B), was coked a s 10 t o 20 percent of coal blends that included Illinois No. 6 and Pocahontas coals . In each case , strong cokes with metallurgical coke properties were produced. This Illinois D&D (B) coal was later washed a t 1.40 specif ic gravity in the Geological Survey's pilot washer. Ash content was reduced from 7.8 t o 6.6 percent and sulfur from 2.73 to 2.44 percent. Use of the washed coa l in place of the raw coal a s 15 percent of a blend with Illinois No. 6 and Pocahontas coals had no apparent effect on coke properties, except for a reduction in a sh and sulfur contents. Results of these coking t e s t s are shown in table 21.

Another coa l sampled in this southern Illinois area was from the Willis seam, about which very little is known. This coal, called Illinois Willis, had a low moisture content of 1.9 percent, the lowest of any coa l sampled. The coal was washed a t 1.35 specific gravity to 6 .5 percent ash and 2.3 percent sulfur. Free-swelling index and Gieseler fluidity were high compared t o other Illinois coals . Coking t e s t s

Shatter t e a t + Z', + 1 1/2"

100% I l l . No. bC (3" r 0")


P"l"eri..~im (-1/S") cokim rime (hr:nin)

(17'' oven)

80% I l l . No 6-G 20% Jmell-B

Coke Yield (ar 3% m i s f u r e ) ( I . of coal aa received)

66.7 69.6 62.6 65.9 4 . 1 3.7

Coke Analysis (dry)

60% 111. No. 6-G 40% J ~ c l l - 8

40% I l l . No. 6 4 60% J ~ e l l - B

75% 111. No. 6 4 (1.30 SP. g x . ) 25% Pour.No. b*

COKING PROPERTIES OF I L L I N O I S COALS 2 1

showed this coal to be very strongly coking, both by itself and in blends. Coke sulfur remained high, however, with from 60 to 80 percent Willis in the blend. Coking results are shown in table 2 2 .

The final coal tested in this ser ies , called here Illinois Reynoldsburg, was from a seam that had been mined near the outcrop in small "dog-holes" many years before and about which very little i s known. Pieces picked up near one of these workings had indicated that this is a high rank coal that is probably low in both ash and sulfur contents. To get samples for coking tes t s and analyses, an opening was dug into the seam far enough back from the outcrop t o avoid oxidized coal. Several truck loads of coal were removed, and channel samples were taken a t four places in this opening. In addition, sufficient coal was mined and brought t o our laboratories for coking t e s t s . Results of these tes t s are shown in table 2 3 . This coal by itself produced a higher than normal gravity coke that would appear t o be very satisfactory for chemical use. I ts blends with medium- and low-volatile coals a l so produced cokes of good quality, although with slightly lower tumbler indices

100% Ill. No. 6." 1 60% 111. No. 6-H 150% Ill. No. 6 6 190% Ill. No. 6 4 1707. Ill. No. 6-H (3" x 0") 40% Jeuell-8 50% J w e l l - B 107. Beskley 30% Pafa. No. 4-B

Lb per sq in Bulk denairy

(Ib per cu f t )

Pulueriracion (-1/8") Caking Lime (hcmin)

(17" oven)

Fired carbon Ash Sulfur

Coke Physical properties

coke Yield (at 3% nalsture) ( x of coal es rcsctved)

70.0 70.8 66.3 67.3 3.7 3.5

Coke Analysis (dry)


than obtained with certain other Illinois coa ls of lower rank. Proper blending probably could improve this strength factor.

Although the Reynoldsburg coa l used for the pilot oven coking t e s t s was not washed, it contained only 5.0 percent ash. A high Giese le r fluidity of 27,500 dial divisions per minute was obtained. The sulfur that might be expected in a raw sample of this coal i s questionable. The coal used for the coking t e s t s had 2.63 percent sulfur. Channel samples taken from nearby locations had sulfur percentages varying from 0.52 t o 1.97.

A small sample of the coa l used for the coking t e s t s was floated in carbon tetrachloride (1.59 specif ic gravity). Although about 97 percent of the coa l floated,

100% 111. No. t-J ( 80% 111. 80. 6 4 65% 111. No. 64 180% 111. No. 64 165% 111. No. 6.J (1/4" x 28'7 20% splmhdam 35% splashdam 20% Pawallton 35% Powellran I

Apparmt gravity

Lb per r q i n Bulk density

(Ib per cu f r )

V0l*ti l . mtter Fixed carbon Anh Sulfur

Coke Yield (at 3% mi&ure) ( X of E0.1 e l received)

65.5 67.1 60.5 62.5

5 . 0 4.6

Crvahins Teat ( a l l colrc)

Coke Analysis (dry)

COKING PROPERTIES O F I L L I N O I S COALS 2 3

the sulfur in this float fraction was reduced to 1.01 percent, dry basis. Not enough coal was available to make tes ts in the pilot oven with the cleaned Reynoldsburg coal. With such a small percentage of reject, however, no major difference in coke physical properties would be expected.

CONCLUSIONS

A study of Illinois coals from the various mining areas and coal seams of the state has shown that these coals al l exhibit coking properties when heated in

TABLE 20 - BESllLTS OF COKING TESTS ON ILLILaIS La. 6-K W U BLWDS (SOUTWeRN IUILaIS)

100% Ill. No. 6-K 80% 111. No. 6-K 6 M Ill. No. 6-K 80% Ill No 6 1 60% 111. No. 6-K (1" x 1 / 4 9 I 20% ~ e u e l l - ~ 1407. Jevell-B 1 202 hc;. N:. 3-8 1401. ~ o s a . NO. 3-8

~ n n b l e r rest S t a b i l i e y h r d n e s s

Lb per 8.3 i n Bulk dens i ty

( l b per E" f t )

Pu lver i r s t ion (-1/8") coking t h e (hr:min)

(17" oven)

v o l a t i l e Mrrer Fixed Carban Aah Sulfur

Coke Yield (at 3% mi.Lure) ( X of coa l as received)

Crushing Test (3" x 1" coke)

Coke Analyais (dry)

2 4 I L L I N O I S STATE G E O L O G I C A L SURVEY C I R C U L A R 4 1 2

the pilotcoke oven. When carbonizedalone, they generally produce cokes with low strength but with physical properties often suitable for chemical coke. When blended with medium- or low-volatile coa ls , hard, strong cokes can be produced that may be of metallurgical coke quality, provided the a sh and sulfur values in the coa ls are sufficiently low.

The lowest sulfur coa ls tes ted were from southern Illinois; one was from Southwestern Ill inois. Those mined in southern Ill inois, from both the No. 5 and No. 6 seams, are used in commercial production of metallurgical coke. Coal from this area a l s o h a s been carbonized in rectangular beehive coke ovens t o produce chemical coke.

Although most Illinois coa ls are either bituminous B or C in rank, some coa l seams outcropping in southern Illinois are of bituminous A rank and have produced coa ls with coking properties similar t o those of the high-volatile coking

TABLE 21 - RESnT'S OF COKING TESTS ON ILLINOIS MVIS M4D DEWVAN COAL BLENDS (SOUTRERN ILLINOIS)

i. U 1 254. Poca. No. 4 4 1252 Poci

iippareni gravity

Lb per .q i n Bulk density

Ilb per cu it)

volat i le Fired carbon Ash S u l f u r


Coke y i e l d ( a t 3% moisture) (% of coal .. rseeived)

Expansion PrsBsure

0 . 9 5 1 .05 0 . 9 52 .5 53 .3 5 2 . 9

C O K I N G P R O P E R T I E S O F I L L I N O I S C O A L S 2 5

c o a l s of t he Appalachian area. With one possible exception, these A-rank Ill inois coa l s are high in sulfur content, making them unsuited for u se a s major const i tu- en t s in metallurgical coke.

TABLE 22 - RESULTS OF COKING TESTS ON ILLINOIS WILLIS COAL BLEWDS (SOUTEENI ILLINOIS)

m b l ~ r test S t a b i l i t y Hardness

s h a t t e r rest +3" +I 1/2"

size t3"

3" x 1" -1"

~pperenf g r a v i t y

100% Ill. wt11i. (Washed eL 1.35 ap. gr.)

Lb per sq tn Bulk d e n s i t y

( I b per cu f c )

Coke P h y s k e l Properties

807. Ill. W i l l i s 20% Wed.-vol. B

coke weld (nr 3% moisture) (7. of coa l as received)

72.8 74.2 69.4 71.1 3 .4 3 . 1

60% Ill. Willie 407. md.-vol . B

80% 111. W i l l i s 20% Paca. No. 3 4

60% 111. w i l l i s 40% Pace. NO. 3 4

26 I L L I N O I S S T A T E G E O L O G I C A L S U R V E Y C I R C U L A R 4 1 2

TABLE 23 - RESULTS OF COKING TESTS ON ILLINOIS REYNOLDSBURG COAL BLENDS (SOUTHERN ILLINOIS)

Date of test:

100% 111. Reynoldsburg (Pit sumole)


Tumbler test Stability Hardness

Shatter test +2" +1 1/2"

Size +3" 3" x 1" -1"

70% Ill. Reynoldsburg 30% Poca. No. 3

Apparent gravity

Coke Yield (at 3% moisture) (X of coal as received)

70% Ill. Reynoldsburg 30% Poca. No. 3-B

Expaneion Pressure

65% 111. Reynoldsburg 35% Poca. No. L B

Lb per sq in Bulk density (lb per cu ft)

Operating Data

Pulverization (-1/8") Caking time (hr:min)

(17" oven)

Crushing Test (3'' x 1" coke)

Coke Analysis (dry)

Volatile matter Fixed carbon Ash Svlfur

C O K I N G P R O P E R T I E S O F I L L I N O I S C O A L S 2 7

REFERENCES

Jackman, H. W., Helfinstine, R. J. , 1964, Coke crushing character is t ics : Illi- nois Geol. Survey Circ. 375, 11 p.

Jackman, H. W., Helfinstine, R. J. , Eissler, R. L., Reed, F. H. , 1955. Coke oven t o measure expansion pressure-Modified Illinois oven, Blast Furnace, Coke Oven and Raw Materials Conference Proc.: Am. Inst . Min. Met. Eng., v . 14, p. 204-219; Il l inois Geol . Survey Reprint Ser. 1955-E, 1 6 p.

Illinois State Geological Survey Circular 412 2 7 ~ p . , 1 fig., 23 tables, 1967

Printed by Authority of State of I l l inois , Ch. 127, IRS, Par. 5 8 . 2 5 .

a survey of the coking properties of illinois...

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