anthracite

Anthracite is the form of coal containing the highest persentage of carbon. Three classes are distinguished:

Name Fixed Carbon
(percent)
Volatile Matter
(percent)
meta-anthracite >98% <2%
anthracite 92–98% 2–8%
semianthracite 86–92% 8–14%

United States sizes, according to the Anthracite Committee. Effective July 28 1947, and amended July 20, 1953.

Name Round Test Mesh
(inches)
Undersize1 Maximum Impurities2 Uses
(some purely historic)
Max-
imum
Min-
imum
Slate3 Bone4 Ash5
Broken through 4 38 1½% 2% 11% hand-fired residential furnaces, gas producers
over 3¼ to 3 15% 7½%
Egg through 3¼ to 3 1½% 2% 11% ditto
over 2 716 15% 7½% 11%
Stove through 2 716 2% 3% 11% ditto
over 1 58 15% 7½%
Chestnut through 1 58 3% 4% 11% ditto
over 1316 15% 7½%
Pea through 1316 4% 5% 12% ditto
over 916 15% 7½%
Buckwheat #1 through 916 13% residential stokers, hand-fired steam boilers
over 516 15% 7½%
Buckwheat #2 (Rice) through 516 13% ditto
over 316 17% 7½%
Buckwheat #3 (Barley) through 316 15% traveling grate stokers
over 332 20% 10%
Buckwheat #4 through 332
15% traveling grate stokers, pulverized
over 364 30% 10%
Buckwheat #5 through 364 no limit 16%  

Notes

1. A tolerance of 1% is allowed on maximum percentage of undersize.  Maximum percentage of undersized is as measured at the preparation plant.

2.When slate content in sizes from broken through chestnut is below the maximum allowed, bone content may be increased by 1.5 times the decrease in slate content.

3. Slate is defined as any material having less than 40 percent fixed carbon.

4. Bone is defined as any material that has 40 percent or more fixed carbon, but less than 75 percent.

5. Ash is determined dry.  A tolerance of 1% is allowed on maximum ash content.

Energy Information Adminstration.
Coal Data: A Reference.
Washington, DC: U.S.G.P.O, 1982.

Page 60.

These values differ somewhat from earlier sources:

Babcock and Wilcock, 1911*
Size Screen sizes,
inches
(through and over)
egg 2.5 to 1.75
stove 1.75 to 1.25
chestnut 1.25 to 0.75
peas 0.75 to 0.50
buckwheat 0.50 to 0.25

*Steam: Its Generation and Use. 34th edition.
New York: Babcock and Wilcock, 1911.

Page 52.

Coal Miner's Pocketbook, 19282
Name passes through passes over round holes square mesh
lump      
steamboat      
cupola      
broken  4½ 3 7/16 over 2 ¾
egg 3 7/16
No. 2 1 9/16  
large stove (No. 3) 2 to 2¼ 1 7/8 to 1½  
small stove (No. 4) 1 7/8 to 1 3/8 1 1/8 to 1  
stove (replaced above 2 sizes by 1928) 2 inch square 1 3/8 inch square  
nut (short for chestnut) 1 9/16 1 1/16  
pea 1 1/16 ½  
buckwheat No. 1 ½ ¼ ½
¼      
buckwheat No. 2 (or rice) ¼ 3/16  
buckwheat No. 3 (or barley) 3/16 3/32 to 1/16  
buckwheat No. 4      
dust      

E. N. Zern, editor.
Coal Miner's Pocketbook.  12th edition.
New York: McGraw-Hill, 1928.

Pages 919, 924, 1209, 1212, 1218, 1244 and others. The descriptions of the sizes in this book are inconsistent, which apparently reflects company to company differences in practices at that time.

home | tools index | search |  to email Sizes drawing of envelope |  acknowledgements | 
help | privacy | terms of use