Further Applications of Coal Petrography

37 Further Applications of Coal Petrography LOUIS G. BENEDICT and WILLIAM F. BERRY Bituminous

Coal Research, Inc., Monroeville,

Pa.

In order to determine the effect of coal rank (as Downloaded by UNIV OF OTTAWA on October 3, 2016 | http://pubs.acs.org Publication Date: January 1, 1966 | doi: 10.1021/ba-1966-0055.ch037

established by reflectance measurement of vitrinite in coal) on the reactions of coal as related to carbonization, gasification, combustion, and other processes, a wide range of bituminous coals were studied. The results show that reflectance measurements can be used effectively: (1) to determine accurately yields of coal carbonization products such as coke, tar, gas, light oil, and liquor from pilot and commercial coke oven; (2) to obtain the heating value and specific gravity properties of gases from these processes; (3) to determine the free swelling index and B.t.u. content of coals; (4) to categorize coals for certain combustion uses; (5) to monitor the oxidation tendencies of coals; (6) to subdivide coals in certain areas of the present coal classification framework.

Q u r i n g the past several years coal petrography has gained acceptance i n certain areas of coal utilization, preparation, and mining as a useful analytical tool. T h e rapid evolution of this analytical technique can be attributed to the development and subsequent refinement of quantitative methods for measuring the reflectance characteristics of vitrinite in coal (8, 14, 15, 16). Mean maximum reflectance has been shown to be directly related to coal rank (14, 16). Moreover, it is known that rank is important in determining certain carbonization and chemical properties. In this paper, we demonstrate how mean maximum reflectance of vitrinite in o i l (hereafter referred to as R..) can be used in place of conventional chemical-rank parameters (volatile matter and fixed carbon) to estimate the relative yields of carbonization products, specific properties of gas produced by carbonization, and chemical properties of coal such as calorific value and free swelling index (FSI). Further, we illustrate that measured R« can be used to detect coal oxidation, to categorize coals for certain combustion uses, and co help classify coals by rank. 577 Given; Coal Science Advances in Chemistry; American Chemical Society: Washington, DC, 1966.

COAL SCIENCE

578

Downloaded by UNIV OF OTTAWA on October 3, 2016 | http://pubs.acs.org Publication Date: January 1, 1966 | doi: 10.1021/ba-1966-0055.ch037

Experimental A wide range of bituminous coals, representing most of the major U . S. coal fields, were microscopically a n d chemically analyzed i n this study. T h e samples tested, approximately 200 i n a l l , were obtained through various coal producers. However, analytical data were not available for a l l samples; carbonization, chemical, and by-product gas data for these subject coals were assumed to be the same as those reported previously i n published sources (7, 9,10,11,17,18). O n l y those carbonization data obtained from tests conducted in 18-inch pilot coke ovens at 9 0 0 ° C . are included. T h e remaining analytical data, approximately one-tenth of the total test results, were obtained from full scale commercial coke oven tests. Because these latter data were not sufficiently represented i n the study, they were not considered i n computing correlation coefficients ( r ) . The method used to analyze the R« of vitrinite i n coal is consistent w i t h that reported b y others (8, 14, 15, 16). Reflectance and chemical properties of the various samples are listed i n Appendix I. Carbonization yields and by-product gas properties are shown i n Appendix II. Relation between Reflectance and Volatile Matter, Calorific Value, and FS1 Previous investigations (14, 15) have shown that R« increases as the fixed carbon content increases and decreases as the volatile matter content increases. T h e relation of R» to volatile matter for coals included here is similar to that reported b y other investigators (14, 15); a progressive increase i n R . is accompanied b y a corresponding decrease i n volatile matter content, as shown in Figure 1.

50.0-1

M M A Maximum RcfUctanc* R», Percent

Figure 1.

Relationship

between reflectance and volatile % daf

matter,

Others have related fixed carbon a n d volatile matter content to calorific value (4, 5) and FSI (12). However, we found that reflectance correlated better with these chemical properties (r = 0.95 and 0.87, respectively). Figure 2 shows the relationship between R* and calorific value for the coals i n this study. In general the calorific value increases sharply with increases i n R . i n the 0 . 5 - 1 . 1 % range, increases slightly i n the 1.1-1.7 R« range, then levels off

Given; Coal Science Advances in Chemistry; American Chemical Society: Washington, DC, 1966.

37.

BENEDICT AND BBRRY

579

Coal Pmtrography

1

I

I i 0.95


14,000 H

13,000 - | 0.4

.

1 0.6

1

1 0.8

1

1 1.0

τ

1 1.2

1

1 1.4

1

1 1.6

1

1 1.8

ι

1 2.0

Mean Maximum Reflaetenca R Q , Peccant

Figure 2.

Relationship

between reflectance and calorific

value

r = -0.77

y = 17.06 - 5.74 χ

î

?

0.62)

*

" > — ι — ι — ι — ι — ι — 0.4

0.6

0.8

1.2

1.6

1.0 Mean Maximum RaAactanca R , Partant

~Ί

1

1.8

1

2.0

0

Figure 3.

Relationship

between reflectance and free swelling

index

in calorific value with increased Ro above 1.7%. This work is i n general agree ment with previous studies i n which correlations between calorific value a n d chemical-rank parameters were presented (4, 5 ) . T h e correlation between Κ· and FSI is shown i n Figure 3. It is apparent that FSI increases linearly i n the 0.5-1.25 Ro range, reaches a maximum i n the 1.2-1.4 range, and then decreases rapidly as Ro increases above 1.4. T h e plotted data are divided into two distinct groups, with the division being made


580

COAL SCIENCE •

Pile* Cole* Ον«π Data

ο Commercial Oven Data


(not included in computation of r)

Mean Maximum Reflectance R», Percent

Figure 4.

Relationship

between reflectance and coke yield

at the 1.25 R# level. Correlation coefficients for these data (r = —0.77 and 0.87) are computed and expressed, respectively, for those points falling above and below the 1.25 R . threshold (Figure 3 ) . Yields of Carbonization

Products

Yields of carbonization products from coal can be estimated from chemi cal-rank parameters such as volatile matter and fixed carbon content (JO, I I ) . Since R e is directly related to these chemical-rank parameters (Figure 1 ) , this petrographic-rank parameter should correlate with these same carbonization

π— —ι—'—ι— —ι— —ι— —ι—"—I 1

0.4

1

0.6

0.8

1

1.0

1

1.2

1.4

1

1.6

I

1

1.8

I 2.0

Mean Maximum Réflectance R , Percent 0

Figure 5.

Refotionship

between reflectance and light oil,

%


37.

BENEDICT AND BERRY

Coal

581

Petrography

properties. Figure 4 demonstrates the relation between Ro a n d coke yield (r = 0.96) as determined i n pilot coke ovens. This observed relationship was expected since R« varies inversely with coal volatility. Figure 4 shows that coke yield increases steadily with increasing reflectance over the entire R« range, 0.7-1.9. Figures 5 a n d 6 show the relation between reflectance a n d the yield of light oil (r = —0.93 and —0.87) expressed successively i n weight percent a n d in gallons per ton of coal. In general, as the average Ro values increase, the yield of light oil decreases rapidly a n d uniformly through the entire bituminous R . range. Downloaded by UNIV OF OTTAWA on October 3, 2016 | http://pubs.acs.org Publication Date: January 1, 1966 | doi: 10.1021/ba-1966-0055.ch037

5.0-,

Mean Maximum Reflectance R , Percent 0

Figure 6.

Relationship between reflectance gallons per ton

and light oil,

19.0-,

9.0 -| 0.4

1

1

0.6

1

1

0.8

1

1

1.0

ι

1

1.2

1

|

1.4

"

1

1.6

1

1

1

1.8


Figure 7.

Relationship between reflectance and gas yield, %


I

2.0

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COAL SCIENCE

Figure 7 depletes the correlation for R « of vitrinite and by-product gas yield (r = — 0 . 9 2 ) . A s was the case i n the correlation of R * w i t h light o i l , the yield of by-product gas exhibits a sharp decrease as coal rank ( R # ) increases from 0 . 7 - 1 . 8 % .


11.0-,

1.0-| 0.4

1

1

1

1

0.6

1

1

0.·

1

1

1.0

1

1

1.2

1

1

1.4

«

1.6

I

ι

1.·

I 2.0

Mean Maximum Reflectance R», Percent

Figure 8.

0-| 0.4

1

Relationship

1 0.6

ι

1

1

O.t

between reflectance and tar yield, %

1 1.0

1

1 1.2

1

1

I

1.4

I 1.6

I

I 1.»

»

I 2.0

Mean Maximum Reflectance R^ Percent

Figure 9.

Relationship

between reflectance and tar yield, gallons

Figures 8 and 9 show that the total tar product correlated reasonably well w i t h R o (r = —0.92 and —0.88, respectively), and that maximum tar yields are obtained from coals at the high volatile rank level while minimum yields are exhibited by low volatile rank coals. Generally, the tar product of a car bonization process is expressed in combination with the yield of light o i l . The relation between the yield of tar plus light o i l and R « was much improved over


37.

BENEDICT AND

BERRY

Coal Petrography

583

12.0-1 lo.o

• Ρ We* Cole* Ovan Data

H

r = y =


g

-0.94 13.94

- 6.23

χ (±

0.62)

6.0-

Τ "

1.0

0.6

1.2

~*—ι— —Γ" 1

1.4

1.6

~τ~ ι·

"*

2.0

Maan Maximum Reflectance R^ Perçant

Figure 10.

Refotionship between reflectance and tar plus light oil,

%

the correlations obtained singly for tar or light oil (r = —0.94 and —0.90, respectively). Figure 10 represents the correlation between yield of tar plus light o i l (in weight percent of coal) and R«. Again, these data show that tar plus light oil yields decrease rapidly from the high to low volatile end of the

Figure 11.

Relationship

between reflectance and tar plus light oil, gallons per ton


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COAL SCIENCE


11.0—1

i.o H

1

0.4

1

1

0.6

1

1

0.8

1

1

1.0

1

1

1

1.2

1

1.4

1

1

1.6

1

1

1.8

1 2.0

Mean Maximum Reflectance R , Percent e

Figure 12.

Relationship

between reflectance and liquor yield, %

coalification series. Figure 11 shows the relationship between the combined products and Ro expressed in gallons per ton of coal. These data exhibit the same sharp linear decrease i n tar plus light oil with corresponding increase in R.. Figure 12, the correlation between liquor yield and Ro, shows that the liquor product decreases as the average vitrinite Ro increases. However, the correlation between Ro and liquor is poor (r = —0.72 ). The degree of scatter (Sy = ± 1.26, where Sy = standard estimate of error for y) is probably a function of moisture differences i n the subject coals; high percentages of moisture increase liquor yields ( 1 7 ) .

*io-| 0.4

1

1 0.6

1

1 0.8

1

1 1.0

1

1 1.2

1

1

1

1.4

1 1.6

1

1 1.8

1

1 2.0


Figure 13.

Relationship

between reflectance and specific gravity of


gas

37.

BENEDICT AND

BERRY


Specific Properties of By-product

585

Coal Petrography Gas

Since Ro is related to volatile matter content (Figure 1), it would be reasonable to expect a correlation between this rank parameter and specific properties of by-product gas. O u r results show that gas specific gravity and gas heating value can, in fact, be estimated fairly accurately from reflectance data. Figure 13, the correlation between specific gravity of by-product gas and Ro (r = — 0 . 9 5 ) , illustrates that the specific gravity of the gas decreases rather uniformly with rank increase. A similar correlation was obtained for R« and the heating value of by product gas. Figure 14 compares gas heating value (B.t.u. per cubic foot) with Ro (r = —0.87) and demonstrates that the heating value of gas decreases gradually as coal rank increases through the 0.7-1.9 Ro range. • Pilot Coke Oven Data ο Commercial Oven Data (not included in computation of r)

ι 0.4

1

— ι• 0.6

1 0.8

«

1 1.0

1

1 1.2

1

1

1

1

1.4

1.6

1

1

• 1.8

1 2.0

Moan Maximum Reflectance R , Percent Q

Figure 14.

Relationship

between reflectance and heating value of gas, B.t.u. per cubic foot

Figure 15 compares the heating value of gas, as expressed i n B.t.u. per pound of coal, to the Ro of the samples analyzed. In general, as the Ro of vitrinite in coal increases, the heating values decrease (r = — 0 . 7 2 ) . A s indi cated by the low coefficient of correlation in Figure 5 (r = — 0 . 7 2 ) , a close relationship between R« and gas heating value does not exist. Therefore, any reference to these data can only be in very general terms. Effects of Oxidation on

Reflectance

Chemical and physical properties of coal are altered by oxidation (2, 3 ) , and this is especially true of volatile matter content and the average R« of vitrinite. However, there is no accurate method for detecting and subsequently determining the rate and degree of change in these properties for a given sample at a given point in time. Recent studies at Bituminous Coal Research, Inc. ( B C R ) revealed that the R* of coal, along with a volatile matter deter-


COAL SCIENCE


586

Figure 15.

Relationship

between reflectance and gas heating value, B.t.u. per pound

mination, could be used to detect oxidation. A correlation between volatile matter content and R« is shown i n Figure 1 (r = —0.96, Sy = ±2.3%). The analytical data plotted were obtained by analyzing "fresh" or newly mined coal samples. After approximately one year some of these same samples were re-analyzed and again plotted on this graphical framework. In replotting these data, significant deviations from the "base" or original volatile matter-R« corre lation line were observed. Figure 16 illustrates the R» a n d volatile matter differences i n the re-analyzed coal ( r = —0.88, Sy = ± 3 . 6 5 % ). Considerably more scatter is apparent i n this plot than i n that of the corresponding data i n Figure 1. Figure 16 shows that: ( 1 ) Oxidation changes are most pronounced in coals having vitrinite with an average R« below 0 . 8 % .

Η 0.4

1

1

0.6

r—ι 0.8

>

1

1.0

!

1

1.2

1

1

1

1.4

1

1.6

«

I

ι

1.8

I

2.0

Μ Μ Π Maximum RaAactarxa R , Partant 0

Figure 16.

Effects of oxidation on reflectance and volatile

matter



37.

BENEDICT AND

BERRY

Coal Petrography

587

(2) Coals occupying the 0.8-1.4 percent R* range are least affected by oxidation. (3) Coals which are characterized by reflectances above 1.4% have intermediate degrees of alteration. A l l coals submitted to B C R for pétrographie analysis are routinely checked for "oxidation" by comparing "as-received" analytical results w i t h the established "fresh coal" R«-volatile matter curve shown i n Figure 1. Coals falling within reasonable limits of this correlation line (within Sy = ± 2 . 3 % ) are accepted as unoxidized; all others are considered oxidized. This method for assessing coal oxidation can be used to good advantage when attempting to predict petrographically coke stabilities from highly oxidized coal samples. Using the relationship presented in Figure 16, it is possible to extrapolate back to the rank of the original or fresh coal. As shown i n Figure 16, this is accomplished by connecting, at right angles, the as-received analysis value with the established fresh coal volatile matter-R« curve, the point Table I.

Comparison of Coke Oven Stabilities Predicted from Highly Oxidized Coals on an As-Received and Corrected Basis

Coal Blend No.

A 500-lb. Oven Stability

Β As-Received Basis

A-B

C Corrected for Oxidation

A-C

1 2 3 4 5 6 7 8 9 10 11 12 13 14

37.8 44.0 50.6 37.5 44.9 50.6 37.6 43.6 49.9 56.0 56.0 57.0 57.0 56.0

37.0 41.0 45.3 35.0 39.5 43.2 37.0 41.0 45.0 47.0 48.0 51.0 51.0 43.0

0.8 3.0 5.3 2.5 4.4 7.4 0.6 2.6 4.9 9.0 8.0 6.0 6.0 13.0

37.0 43.0 49.0 37.0 43.0 49.0 37.0 43.0 49.0 53.0 54.0 56.0 56.0 54.0

0.8 1.0 1.6 0.5 1.9 1.6 0.6 0.6 0.9 3.0 2.0 1.0 1.0 2.0

of intersection being the fresh coal rank as determined by the subject parame ters. This method of rank inference has been employed at B C R with consid erable success. Table I illustrates several cases i n which this oxidation correc tion technique was used to predict coke oven stabilities from highly oxidized coals. T h e table compares 500-lb. coke oven stabilities with stabilities calcu lated from pétrographie analysis. The stabilities calculated on an as-received basis were found to deviate considerably from the actual oven values, deviations being as high as 13 stability points. However, stabilities predicted from data which were corrected for oxidation compare favorably with the empirical test results—i.e., ± 2 stability points. Combustion

Characteristics

Previously it had been thought that combustion characteristics of coals could be determined only from actual tests ( 6 ) . However, testing i n a full



588

COAL SCIENCE

A S H FUSION TEMPERATURE

Figure 17.

Refotionship between reflectance, FSI, screen size, ash temperature, and combustion performance

fusion,

scale combustion unit is time consuming and expensive. M a n y attempts have been made to correlate the domestic stoker characteristics of coal with laboratory test results and with chemical and physical properties. The results of these studies indicated that the combustion behavior of coal could be determined best from full scale tests ( 6 ) . W o r k is being conducted presently at B C R to relate pétrographie characteristics to coal combustion performance. Preliminary results of the study, although incomplete, show a reasonable correlation between certain pétrographie properties and coal combustion behavior. Advancement in this research area was made possible through the development of the B C R 7-lb. combustion furnace (13, 2 9 ) . In this furnace, coals can be classified quantitatively in terms of their relative combustion perform-


37.

BENEDICT AND BERRY

Coal Petrography

589

-£ c

I

Ο


-J ·· · I %· ·· • •

>

•if·· 1

4 • •

•

•

·

•

• • ·· »·· ·· ·· ·• • ·· ·· •· • ·· • • •

•

t

Ο

16,000

14,000 13,000

11,000

9,500

•

·

8,300

MOIST, MINERAL - MATTER - FREE BTU Ηίςη-νοΙ. A bit.

Figure 18.

L

High-vol. Β bit.

High-vol. C bit. or subbit A

4-

Subbit Β

4-—-4- Lignite Subbit. C

Typical U.S. coals graphed according to standard by rank (12)

classification



590

COAL SCIENCE

ance. Prior to development of this test equipment, it was not possible to determine adequately combustion characteristics on such a conveniently small scale. Several approaches are being taken i n an attempt to relate pétrographie composition with combustion behavior. Figure 17 shows h o w R« along w i t h FSI and ash fusion data may be used to predict the burning rate of coals i n a specific combustion type (cross-feed stoker). In general, as R« a n d FSI i n crease and ash fusion temperatures decrease, coals require more grate surface to insure optimum burn-out and minimum loss of combustibles i n the ash. A t present, a pétrographie combustion correlation is being worked out w h i c h should provide ultimately a general classification of coals for use i n several combustion processes. T h e results of this study w i l l be reported at a later date. Classification

of Coal by Reflectance

T h e coal rank classification system commonly used i n the U . S . is based o n the relationship between calorific value and fixed carbon content ( I ) . F o r the most part, the system serves to classify effectively coals having fixed carbon contents greater than 6 9 % , but it is not possible to classify adequately coals Volatil* Matter, Partant, daf 50-

AS

-ι

45

43+

41+

39

36"

32

29

26

23

21

19

17+

16

15

1

ι

I

ι

I

ι

I

ι

I

ι

1

1

1

1

1

i

1

1

1

1

1

1

1

1

1

1

1

1

1

I I i i

m

14,000 H

>

13,000

τ

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

1

2.0

Mean Maximum Reflectance R , Percent Q

Figure 19.

Classification

of coals by pétrographie parameters

and

chemical

below this fixed carbon level. Since a correlation exists between chemical-rank parameters and R.. (Figures 1 and 2 ) , there is reason to believe that these problem area coals could be categorized more accurately if petrographic-rank parameters were included i n the current coal classification system. Figure 18 illustrates the present method for classifying coals on the basis of chemical composition; Figure 19 illustrates a tentative R« chemical rank classification. Obviously, insufficient data are presented i n Figure 19 to substantiate whether this classification scheme is, i n fact, an improvement over that shown i n Figure


37.

BENEDICT AND

BERRY

Coal Petrography

591

17. Figure 19 does show, however, that the modified classification improves the correlation in the high volatile rank range—i.e., coals with R . values i n the rank range below 1 . 1 % . W i t h additional analytical data, the authors feel that a rank classification system of this type could be established on reflectance-chemical properties w h i c h w o u l d be consistent throughout the entire coalification series.


Summary This investigation shows that the average reflectance of vitrinite i n coal (Re) can be used to estimate carbonization product yields, by-product gas properties, chemical properties, oxidation effects, and combustion behavior. Moreover, R« along w i t h calorific value and volatile matter content might be employed to classify accurately and consistently coals of all ranks.

Literature Cited (1) American Society for Testing Materials, Philadelphia, Pa., D-388-38. (2) Bayer, J. L., Denton, G. H., Chang, M. C., "Abstracts of Papers," 145th Meet ing, ACS, September 1963, p. 2K. (3) Benedict, L. G., Berry, W. F., Presented at the Coal Division of the Geological Society of America, Miami, Florida, 1964. (4) Fieldner, A. C., Selvig, W. Α., Frederic, W. H., U. S. Bur. Mines, Rept. Invest. 3296R (1936). (5) Francis, W., "Coal," p. 317-8, Edward Arnold Publisher, Ltd., London, 1954. (6) Helfenstine, R. J., Illinois State Geol. Surv., Rept. Invest. 151 (1951). (7) Isenberg, N., Jackman, H. W., "Investigation of Beckley Seam Coal Blended with Wheelwright Coal for Use in the Production of Metallurgical Coke," Inland Steel Co., East Chicago, 1945. (8) Kotter, K., Brennstoff-Chem. 41, 263 (1960). (9) Montgomery, C. R., Verno, L. J., Trans. Mining Soc., AIME, Preprint 62F82 (1962). (10) Parry, V. F., U. S. Bur. Mines, Rept. Invest. 3482 (1939). (11) Perch, M., Russell, C. C., Presented at Joint Fuels Conference of Coal Division, AIME and Fuels Division, ASME, November 1948. (12) Rose, H. J., Presented at the Joint Solid Fuels Meeting of the Coal Division of Fuels Division of AIME and ASME, October 1958. (13) Saltsman, R. D., Trans. Mining Soc., AIME, Preprint 64F35 (1964). (14) Shapiro, N., Gray, R. J., Proc. Illinois Mining Inst. 68, 83 (1960). (15) Shapiro, N., Gray, R. J., Eusner, G. R., Proc. Blast Furnace, Coke Oven, Raw Mater. Comm. 20 (1961). (16) Van Krevelen, D. W., Shuyer, J., "Coal Science," p. 164-8, Elsevier Publishing Co., New York, 1957. (17) Wolfson, D. E., Birge, G. W., Lynch, J. H., U. S. Bur. Mines, Rept. Invest. 5628 (1960). (18) Wolfson, D. E., Reynolds, D. Α., U. S. Bur. Mines, Tech. Paper 693 (1946). (19) Zawadzki, Ε. Α., du Breuil, F., ASME, Tech. Paper 59FU3, 1959. RECEIVED October 5, 1965.


592

COAL SCIENCE Appendix 1.


al No.

Chemical and Pétrographie Data

Pétrographie Data Reflectance, R Vofotile Matter, daf 0

Chemical Data B.t.u., daf

1 2 3 4 5

1.08 1.04 1.08 1.08 1.19

33.1 34.5 33.1 32.9 29.3

15,365 15,470 15,505 15,500 15,527

6 7 8 9 10

1.17 1.25 1.33 1.33 1.25

30.0 27.2 25.0 25.0 27.3

15,560 15,670 15,625 15,675 15,570

11 12 13 14 15

1.24 1.58 1.76 1.64 1.52

27.7 20.8 17.9 19.7 20.2

15,660 15,765 15,830 15,800 15,725

16 17 18 19 20

1.86 1.74 0.93 0.96 0.86

16.0 17.4 38.1 37.7 40.3

15,730 15,770

21 22 23 24 25

0.88 0.90 0.97 0.97 1.00

39.7 39.4 37.2 37.1 36.8

26 27 28 29 30

0.85 0.90 0.91 0.94 0.94

40.2 38.9 38.5 37.9 37.8

31 32 33 34 35

0.93 0.83 0.86 0.97 0.72

37.2 40.8 39.9 37.0 43.6

36 37 38 39 40

0.79 0.86 0.86 1.08 0.97

42.0 40.4 39.7 33.4 37.2

41 42 43 44 45

1.04 1.12 1.14 1.17 1.15

34.5 31.6 30.8 30.3 30.5

46 47 48 49 50

0.95 0.96 1.08 0.90 0.81

37.4 36.9 32.8 38.7 41.6

— — — — — — — — — — — — — — — — — —

_

FSI

— — — — — — — — — — — —

6 5

6%

— — —

7

6

6 6%

—

6%

— —

8 6 5

— — —

_

—

—

— — — —

— — 5—


37.

BENEDICT AND BERRY

Appendix I.


Coal No.

593

Coal Petrography Continued

Pétrographie Data Reflectance, Ro Volatile Matter, daf

51 52 53 54 55

0.82 0.91 0.84 1.08 1.06

41.6 38.9 39.7 33.0 33.7

56 57 58 59 60

1.10 1.80 1.15 0.73 0.83

32.0 16.3 30.3 43.0 40.6

61 62 63 64 65

1.06 0.70 1.00 1.26 1.17

33.6 43.7 36.0 27.1 30.1

66 67 68 69 70

1.21 1.80 1.74 1.66 1.64

28.6 16.3 17.6 18.3 18.9

71 72 73 74 75

1.61 1.48 1.40 1.38 1.33

19.6 21.5 22.8 23.5 24.9

76 77 78 79 80

1.21 1.22 1.20 1.14 1.11

27.2 28.0 29.0 31.5 33.0

81 82 83 84 85

1.00 1.01 0.97 0.90 1.34

34.0 36.0 36.7 38.0 24.6

86 87 88 89 90

1.00 1.58 1.46 1.47 1.54

36.2 19.8 23.0 23.0 20.4

91 92 93 94 95

0.80 0.72 1.41 0.81 0.94

42.0 44.0 23.2 41.0 37.3

96 97 98 99 100

1.64 0.56 0.97 1.60 1.10

18.8 47.8 37.1 19.2 32.0


— — — — — — — — — — — — — — — — —

FSI

—

6— 8 8 8 6 8 5 5 8% 4%

7% 9 8 8i/fe 6%

— — —

— — — —

— — — —

— — — —

— — — — — — — — —

— — — — — — — —

8 8% 8% 9

— — — —

9— 6% 7

— — — —


— 7

IVz

8

COAL SCIENCE

594 Appendix I.


Coal No.

Continued

Pétrographie Data Reflectance, R# Volatile Matter, daf

Chemical Data B.t.u.,daf

FSI

101 102 103 104 105

1.14 Lie 1.68 1.68 1.73

29.4 30.5 18.2 18.5 17.8

— — — — —

8 8% 8

106 107 108 109 110

1.70 LOO 1.01 1.11 1.05

18.0 35.4 35.2 32.5 34.5

— — — — —

7% 8 8% 8% 8

111 112 113 114 115

1.74 1.65 1.71 1.12 1.08

17.4 18.5 17.7 31.4 33.0

— — — — —

7 7 6 6

116 117 118 119 120

0.93 0.88 0.91 1.19 1.18

38.2 39.3 38.5 29.6 29.2

— — — — —

121 122 123 124 125

1.12 0.94 0.95 0.88 0.84

31.8 38.0 37.0 41.2 40.1

— — — — —

8

126 127 128 129 130

0.79 0.82 0.82 0.74 0.80

41.8 41.4 41.8 42.5 41.6

— — — — —

— — 6% 4% 6

131 132 133 134 135

0.72 0.63 0.94 0.90 0.88

42.7 46.1 38.2 39.7 40.5

— — — — —

3% — 7% 7%

136 137 138 139 140

0.83 1.03 0.80 0.74 1.27

40.4 36.1 41.5 42.0 27.0

— — — — 15,630

6% 8% 6 — —

141 142 143 144 145

1.40 1.59 1.75 0.68 0.67

23.3 19.9 18.0 — —

15,540 15,620 15,680 14,600 14,690

— — — — —


IVz

—

8

— — — — —

— — 6% 6

IVz

37.

BENEDICT AND BERRY

Appendix I.


Coal No.

Continued

Pétrographie Data Reflectance, R» Volatile Matter, daf

146 147 148 149 150

0.73 0.75 0.77 0.74 0.73

160 161 162 163 164 165

0.74 0.75 0.76 0.77 0.78 0.80

166 167 168 169 170

0.80 0.80 0.80 0.80 0.81

172 173 174 175

0.82 0.82 0.82 0.81

176 177 178 179 180

0.81 0.85 0.85 0.85 0.88

181 182 183 184 185

0.88 0.88 0.89 0.89 0.91

186 187 188 189 190

0.92 0.96 1.02 1.03 1.08

191 192 193 194 195

1.08 1.08 1.12 1.16 1.17

196 197 198 199 200

1.17 1.19 1.22 1.23 1.25

201 202 203 204 205

1.24 1.25 1.28 1.35 1.34

595

Coal Petrography

— — — — — — —

— — — — — — — —

_

— — — — — —

Chemical Data B.t.u., daf 14,690 14,500 14,490 14,750 14,950 14,850 14,900 14,750 14,850 14,800 15,000 14,950 14,900 14,750 14,550 14,650 14,740 14,750 14,830 14,950 15,000 15,000 14,900 14,780 15,050 14,980 14,950 14,950 15,150 14,820 15,200 15,300 15,230 15,500 15,350 15,450 15,500 15,550 15,450 15,450 15,500 15,450 15,600 15,500 15,550 15,650 15,650 15,600 15,800 15,550


FSI

_

— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —

596

COAL SCIENCE Appendix I.


Coal No.

Continued

Pétrographie Data Reflectance, R. Volatile Matter, daf


FSl

206 207 208 209 210

1.33 1.30 1.40 1.52 1.57

— _ _ _ _

15,650 15,550 15,450 15,650 15,650

— _ _ — —

211 212 213 214

1.58 1.72 1.59 1.64 1-74

_ _ _ _ —

15,650 15,650 15,600 15,750 15,650

_ _ —

1.74 1.77 1.86 _

_ _ _

15,700 15,800 15,750 _

_ _ _

2

1

5

216 217 218 219

Appendix II.

Yield* of Carbonization

Yield, percent by weight of Coal'

Coal No.

Coke

Tar

Light Oil

Gas

Liquor

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

71.4 70.7 71.3 71.2 71.4 73.9 74.3 73.2 75.7 71.7 73.8 80.8 82.7 80.6 80.1 84.3 84.0

6.2 6.7 6.9 6.2 5.6 5.8 5.7 5.1 4.9 5.2 6.2 2.7 2.3 3.0 3.2 1.6 2.0

1.20 1.20 1.06 1.01 0.97 1.11 0.88 0.75 0.85 0.89 0.75 0.51 0.52 0.59 0.64 0.48 0.50

13.9 15.8 15.5 13.8 13.4 13.4 13.7 13.6 13.7 12.6 14.2 12.3 11.3 11.1 11.5 10.6 10.6

6.1 5.3 5.1 7.7 7.6 4.7 5.6 8.1 5.8 8.7 5.2 3.2 3.6 4.0 3.8 2.4 2.7

18 19 20 21 22 23 24 25

68.0 68.8 69.5 68.1 69.6 70.0 69.8 71.1

6.2 6.5 6.3 7.2 6.0 6.2 7.3 5.7

1.25 1.24 1.20 1.23 1.31 1.14 1.17 1.32

15.6 15.3 15.2 16.1 14.9 15.2 15.2 14.8

8.0 7.9 7.8 7.7 7.6 7.4 6.8 6.6


37.

BENEDICT AND BERRY

Appendix I. Coal No.

597

Coal Petrography Continued

Pétrographie Data Reflectance, R, Volatile Matter, daf

Chemical Data B.t.u.,daf

FSI


Commercial Coke Oven Data' 220 221 222 223 224

1.08 1.04 1.12 1.14 1.17

33.4 34.5 31.6 30.8 30.3

— — — — —

— — — — —

225 226 227 228 229

1.15 0.95 0.96 1.08 0.90

30.8 37.4 36.9 32.8 38.7

— — — — —

— — — — —

' D a t a not used in computing correlation coefficients

(r).

Products and By-Product Gas Data' Yield per ton of Coal'

Properties of Gas Heating Value

Tar, (gal)

Light Oil in Gas (gal)

Specific Gravity

B.t.u. per cubic foot

B.t.u. per pound of Coal

12.6 13.5 13.8 12.4 11.5 11.5 11.5 10.6 10.0 10.6 12.6 5.5 4.7 6.2 6.5 3.2 4.1

3.30 3.20 2.91 2.75 2.69 3.02 2.44 2.07 2.34 2.47 2.08 1.41 1.45 1.63 1.77 1.29 1.36

0.364 0.379 0.387 0.380 0.349 0.345 0.352 0.352 0.351 0.341 0.362 0.302 0.279 0.275 0.282 0.274 0.267

592 599 576 554 580 578 563 555 545 573 559 555 527 533 533 506 500

2990 3290 3050 2640 2960 2980 2900 2840 2820 2790 3080 3000 2830 2850 2890 2590 2610

12.9 13.3 12.9 14.9 12.2 13.0 15.3 11.9

3.48 3.47 3.33 3.42 3.64 3.17 3.25 3.16

0.393 0.383 0.405 0.401 0.399 0.389 0.383 0.381

589 587 601 606 585 595 601 587

3110 3110 3010 3230 2900 3080 3190 3020


598

COAL SCIENCE Appendix II. Yield, percent by weight of Coal


9

Coal No.

Coke

Tar

Light Oil

Gas

Liquor

26 27 28 29 30

66.7 67.7 69.1 70.6 69.7

6.3 6.9 7.2 6.8 8.1

1.19 1.19 1.24 1.22 1.13

16.4 15.8 16.7 15.5 15.4

9.4 8.1 6.2 5.6 4.7

31 32 33 34 35 36 37 38

70.4 66.2 65.8 70.1 65.3 67.6 66.6 66.4

7.4 7.8 7.8 6.8 9.4 7.5 6.7 6.7

1.23 1.40 1.22 1.11 1.23 1.27 1.34 1.23

15.7 16.6 16.3 15.3 16.4 16.3 15.6 16.6

5.0 6.9 8.7 6.8 7.1 7.4 9.0 9.2

39 40 41 42 13 44 45 46 47 48 49

72.4 69.4 69.3 73.4 71.7 73.3 72.7 67.0 64.7 98.2 68.4

—

50 51 52 53

65.1 63.1 65.4 65.4

6.7 7.7 7.2 7.8

1.41 1.47 1.32 1.31

17.3 17.0 16.6 16.7

7.5 8.4 7.9 7.0

54 55 56 57 58 59 60 61 62 63 64 65 66 67 68

68.9 70.2 70.0

6.3 7.0 6.4

1.01 0.96 0.97

12.9 13.3 13.2

10.0 8.1 8.9

64.9 67.0 70.2 64.3 70.8 75.7 73.5 75.0

7.8 6.9 5.6 7.8 7.4 6.4 6.8 6.5

1.31 1.03 1.02 1.24 1.05 0.77 0.77 0.81

17.0 16.2 14.6 16.7 15.0 12.0 12.7 12.5

8.3 8.3 8.1 9.0 5.2 5.5 5.6 5.0

fiQ

70 71 72

—

—

—

—

— —

—


—

37.

BENEDICT AND BERRY

599

Coal Petrography

Continued


Yield per ton of Coal*

Properties of Gas Heating Value

Tar, (gal.)

Light Oil in Gas (gal)

Specific Gravity



13.1 14.4 14.8 14.0 15.8

3.33 3.30 3.46 3.41 3.29

0.413 0.388 0.406 0.386 0.381

578 602 592 606 606

3030 3270 3340 3230 3350

14.9 16.2 16.3 14.1 19.7 15.7 13.9 13.8

3.41 3.89 3.39 3.07 3.43 3.54 3.85 3.40

0.375 0.407 0.400 0.382 0.414 0.417 0.399 0.409

607 627 607 603 621 601 589 587

3370 3290 3280 3210 3260 3130 3050 3070

12.3 12.6 12.9 8.4 8.2 8.3 8.5 14.6 12.0 8.4 15.9

2.46 2.73 2.69 2.46 2.14 2.32 2.45 2.15 1.89 2.05 2.97

0.370 0.394 0.372 0.373 0.368 0.358 0.359 0.413 0.405 0.375 0.389

574 586 581 548 552 542 544 596 558 565 630

13.4 15.8 14.8 16.2

3.86 4.04 3.64 3.63

0.432 0.416 0.416 0.413

597 611 614 614

3180 3320 3250 3300

13.0 14.6 13.3

2.82 2.67 2.70

0.369 0.358 0.356

555 573 564

2610 2810 2760

16.1 14.5 11.4 16.1 14.6 13.2 14.1 13.2

3.63 2.87 2.85 3.46 2.92 2.14 2.15 2.26

0.419 0.416 0.368 0.419 0.365 0.312 0.330 0.330

606 577 576 583 590 544 557 545 466 515

3260 2990 3020 3090 3140 2770 2840 2750 2570 2680

500

2610

— — — — — — — — — —

3000 2930


600

COAL SCIENCE Appendix

II.

Yield, percent by weight of Coal*

Coke

Tar

Light Oil

76

—

—

—

—

—

78 79 80 81 82 83

— — — — — —

— — — — —

— — — — — —

— — — — — —

~ ~ — ~ — —

220 221 222 223 224 225 226 227 228 229

72.8 69.6 71.5 72.5 74.1 74.4 67.1 65.7 70.8 67.4

— — — — — — — — — —

— — — — — — — — — —


Coal No.

—

Cas

Liquor

Commercial Coke 1.08 1.04 1.12 1.14 1.17 1.15 0.95 0.96 1.08 0.90

' Carbonized at 900°C. in 18-inch pilot coke ovens. ' C o k e , tar, and light oil are reported on dry basis.

Discussion John Harrison: W e have noticed that the moisture content of a coal, either before a briquet is made or as a result of adding water during the wet polishing process, can drastically affect the reflectance. This is true of high volatile coals and to a lesser extent the low volatile coals. Other things being equal, coal with the higher moisture content has the lower reflectance. W h a t standards have you set up or what precautions have you taken to prevent this effect from influencing your R« values? L o u i s G . Benedict: W e have not observed any significant changes i n mean maximum reflectance in a given coal sample with increasing moisture content. W e have observed, however, that significant alterations in reflectance result from oxidation. As fresh coal is progressively oxidized, mean maximum reflectance decreases, reaches a minimum, and then increases steadily with con-


37.

BENEDICT AND BERRY

601

Coal Petrography

Continued Yield per ton of Coal'


Tar, (gal.)

Light Oil in Gas (gal.)

Properties of Gas Heating Value Specific Gravity



556

2870

575 592

2980 3200

586 592 602 616

2960 3320 3160 3250

Oven data' 8.8 11.1 7.2 7.2 6.7 — 11.6 9.0 8.4 13.3 4

1.80 1.79 1.92 1.90 1.42 — 1.60 1.80 1.73 1.97

0.385 0.390 0.414 0.390 0.378 — 0.417 0.412 0.397 0.409

Data not used in computing correlation coefficients

544 574 490 542 542 543 571 544 525 584 (r).

tinued oxidation. This pattern of alteration was observed i n coals occupying the reflectance rank range 0 . 7 - 1 . 7 % . Briquets prepared at B C R for pétrographie analysis are maintained i n a desiccator for an extended period prior to microscopic analysis. Specific high moisture coals have been analyzed for reflectance at regular intervals following their insertion in the desiccating atmosphere; under these conditions of continued desiccation, reflectance remained relatively constant.


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