A glossary of mining and metallurgical terms

22 A GLOSSARY OF MINING AND METALLURGICAL TERMS.
ihracite also stonecoal or culm, and speak of a semi-anlhracih as
steam-coal. Any coal aflvantao;eously used for generating steam is
called a steam-coal in the United States. The solid carbon remain-
ing after the expulsion of volatile matters from bituminous coal or
lignite is called coke. Commercial coke, however, must have a cer-
tain coherence and strength ; and the coals which furnish it in this
condition are called coking coals. A peculiar bituminous coal of
Indiana and Ohio, which breaks in blocks, and is used raw without
coking, to some extent, as a blast-furnace fuel, is called block-r-oal.
Anthracite is divided in the United States according to the color of
the ash after burning, \nto ruhite-ash.,7-ed-ash, and pink-ash coal. It
is also classified for the market according to the size of the pieces
(see Coal-breaker), as follows: Lump includes the largest lumps as
they come from the mine. The other .sizes pass over and through
sieve-meshes of the size named, the figures signifying inches, and
thus indicating roughly the average limit of diameter for the pieces
in each size, viz. :
Steamboat,
No. 1, Broken or gr
No. 2, Egg,
No. 3, Large stove,
No. 4, Small stove,
No. 5, Chestnut,
No. 6, Pea,
No. 7, Buckwheat, is rarely made, except when the coal is washed
on the screens, and the cheMnut and pea have the larger dimensions
above given. It is the smallest size, and usually included in the
dirt or culm.
Coal-breaker. A building containing the machinery for break-
ing coal with toothed rolls, sizing it with sieves, and cleaning it for
market.
Coal-pipes, Newc. Very thin irregular layers of coal.
Cobalt-ores. Cobalt-speiss {smaltine, chloanthite when niccoliferous,
.'iaffiorite when ferriferous, an ari^enide of cobalt with or without
nickel or iron); cobalt glance and cobalt pyrites (.wialtife and Unncrite,
sulphides of cobalt); cobalt bloom {erythrite, arseniate of cobalt).
Cobbing, Corn. Breaking ore to sort out its better portions.
See Spall.
Cobble, Penn. An imperfectly puddled ball which goes to pieces
in the squeezer.
through 7
Cobre ores. Copper ores from Cuba.