Shrop. Workable measures, usually ironstone. Syn:fey
Studies gathering together the information that is required for a decision
whether and how to proceed further. A study of this kind may vary from a
preliminary estimate of mill cost to a very complete survey that may
include a market analysis, mining plan with ore grades and mining cost,
metallurgical testing, process development, plans for the mill, cash flow
analysis, etc. SME, 2
See:alunogen; halotrichite.
A metamorphic rock in which porphyroblastic crystals of amphibole (usually
hornblende) tend to form stellate or sheaflike groups on the planes of
foliation or schistosity. CF:amphibolite
AGI
a. The thin end of a wedge-shaped piece of rock or coal.
b. A sharp edge, such as that produced when a brick is cut lengthwise from
corner to corner to produce a triangular cross section.
See also:knife edge
Firebricks with tapered ends. Osborne
See:satin spar
Copper granulated by being poured molten into cold water.
Webster 3rd
a. See:jamesonite
b. A capillary, fibrous, or feathery habit of an antimony-sulfide mineral,
specif. jamesonite, but including stibnite and boulangerite.
Imperfect quartz crystals that meet at an angle of a crystallographic
plane so that a cross section somewhat resembles a feather.
Litharge crystals.
An organic excrement, mainly of invertebrates, occurring esp. in modern
marine deposits but also fossilized in some sedimentary rocks; usually of
a simple ovoid form less than a millimeter in length, or more rarely
rod-shaped with longitudinal or transverse sculpturing, devoid of internal
structure, and smaller than a coprolite. Also spelled faecal pellet.
AGI
See:universal stage
a. Material treated for removal of its valuable mineral contents. Also,
feed to any machine or process along a mill's flow line. Also called
mill-head ore. Pryor, 3
b. The process of supplying material to a conveying or processing unit.
Nichols, 1
c. The forward motion imparted to the drills or cutters of a rock-drilling
or coal-cutting machine.
d. A mechanism that pushes a drill into its work. Nichols, 1
e. The longitudinal movements imparted to a drill stem to cause the bit to
cut and penetrate the formation being drilled. Long
f. See:drill feed
g. The distance that the drill stem on a diamond drill may be advanced
before the rods must be rechucked. Long
h. In stonecutting, sand and water employed to assist the saw blade in
cutting.
System of valves or other mechanical device controlling the rate at which
longitudinal movements are imparted to the diamond- or rock-drill stem
and/or the cutting teeth on a coal-cutting machine. Long
A small valve, usually a needle valve, on the outlet of the hydraulic-feed
cylinder on the swivel head of a diamond drill; used to control minutely
the speed of the hydraulic piston travel and, hence, the rate at which the
bit penetrates the rock being drilled. Also called drip valve; needle
valve. Long
In rotary kilns, special fire-clay shapes or rotary-kiln blocks so
installed as to reduce the kiln diameter.
a. Small fissures or cracks through which methane or other gases escape
from the coal. As working faces are advanced, fresh feeders are
encountered in each fall of coal. Kentucky
b. Any flow of water or gas entering a mine. BS, 10
c. A conveyor or bunker structure for delivering coal or other broken
material at a controllable rate. See also:feeder conveyor;
Lofco car feeder. Nelson
d. A flow of water from the strata or from old workings. Nelson
e. A small ore vein leading to a larger one. See also:feeder vein
A pair of reversible conveyors, entry and exit, which provide for repeat
feeding of metal being processed through a rolling mill.
A portable feeding and crushing unit which can move on its own or often be
installed in a stationary position. The unit has a feed chain (often
referred to as a flight chain) inside a shallow built-on hopper that drags
the mined ore into a rotating breaker head (shaft), which has various
sizes of breaker heads (known as piks). These piks rotate downward as the
chain drags the stone or ore into it, crushing the ore to various sizes
depending on the height of the mounted rotating breaker head.
Syn:stamler
A feeder circuit is a conductor or group of conductors and associated
protective and switching devices installed on the surface, in mine
entries, or in gangways, but not extending beyond the limits set for
permanent mine wiring.