A glossary of mining and metallurgical terms

24 A GLOSSARY OF MINING AND METALLURGICAL TERMS.
Combined carbon. Tliat portion of the carbon in iron or steel
which is not visible as graphite, and is supposed to be alloyed or
chemically combined with the iron.
Compass. An instrument like the ordinary nautical or surveyor's
compass, though sometimes otherwise marked, and having a clinometer
attached.
Also, a dip-compass, for tracing magnetic iron ore, having
a needle hung to move in a vertical plane.
Concentration. The removal by mechanical means of the lighter
and less valuable portions of ore.
Concentrator. An apparatus in which, by the aid of water or air
and specific gravity, mechanical concentration of ores is performed.
Condenser. A vessel or ciiamber in which volatile products of
roasting or smelting (e. (/., mercury or zinc vapors) are reduced to
solid form by cooling, or in which the fumes of furnaces, containing
mechanically suspended as well as volatile metallic matters, are ar-
rested.
Conglomerate. A rock consisting of fragments of other rocks
(usually rounded) cemented together.
Consume. The chemical and mechanical loss of mercury in amal-
y-amation.
Contact. The plane between two adjacent bodies of dissimilar
rock. A contact-vein is a vein, and a contact-bed is a bed, lying,
the former more or less closely, the latter absolutely, along a contact.
Continental process. See German process.
Converter. See Bessemer process.
Cope. 1. Derb. To contract to mine lead-ore by the dish, load, or
other measure. 2. The upper part of a Jiask, separable from the
lower part. See Drag.
Coper, Derb. One who contract* to raise lead-ore at a fixed rate.
Copperas. Ferrous sulphate.
Copper-ores. Native copper ; red copper-ore (cwj^Wie, protoxide);
green and blue malachite [malachite and azurite, carbonates); copper
glance {chalcocite, sulphide); purple copper (variegated or peacock
ore, bornite, sulphide of copper and iron); gray copper {fahl-ore,
tetrahedriie, sulphaut'imon'ide of copper and other metals); yellow
copper [copper-pyrites, chalcopyrite, sulphide of copper and iron);
copj)cr-lead ore [bo iirnonitd, su\\)ha.nt'nnomde of lead and capper);
black copjier-ore (an earthy and variable mixture of sulphide and
oxide of copper).
Copper-j>lates, Austr. and Pac. The plates ofamalgamated copper