METALLURGY OF CAST IRON.
TABLE 5.—ANALYSES OF COKE FROM DIFFERENT LOCALITIES.
Where Made. Fix<.d carbon. Ash.. Sulphur.
Connellsville, Pa. (Average of 3 samples.) . .. 88.96 9-74 0.810
Chattanooga, Tenn. '4 So.6r 16.34 1-595
Birming-ham, Ala. ' 4 " 87-29 10.54 I-I95
Pocahontas, Va. 92-53 5-74 0-597
New River, W. Va. ' 8 " 92.38 7.21 0.562
Big- Stone Gap, Ky. ' 7 93-23 5-69 0.749
Coke of a silvery metallic lustre and possessing- a solid, hard body, with cells well connected and of uniform structure, can generally be called c c good coke.'' The hidden element that might do serious harm in such coke is sulphur or phosphorus, for these can be high or low in any grade of coke. This can only be properly determined by analysis. The coke generally condemned by the consumer, especially the founder, is small sized coke, mixed with, ash cinder or coke dust; then again coke that is. dark in its general appearance, having black ends, and soft in quality. Even when, the coke has all other commendable qualities but is in small pieces, such is often sufficient to 9 produce bad results in melting iron. Then again coke may not possess the much desired * * silvery or bright metallic lustre" and still be good, if it is only large and hard in character, possessing a good cellular structure. The harder or more dense the coke, the stronger blast is required in melting iron.
Black ends are of two kinds. One is called black tops and the other black butts, the latter coming from the bottom of the charge of coal as it lays in an oven, and the former from the top. Black tops are rarely injurious, while black butts can be. These latter may often be caused by reason of an inch or more of theethod usedt has proved an excellent fuel for this and kindred uses.''