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drum filter

Cylindrical drum, which rotates slowly through trough-shaped bath, fed
continuously with thickened ore pulp.

drum horn

Wrought-iron arms or spokes projecting beyond the surface or periphery of
a flat-rope drum, between which the ropes coil or lap. See also:spider
Fay

drumman

See:slope engineer

drumming

The process of sounding the roof of a mine to discover whether rock is
loose. Fay

drummy

a. Loose coal or rock that produces a hollow, loose, open, weak, or
dangerous sound when tapped with any hard substance to test condition of
strata; said esp. of a mine roof. Fay; BCI
b. The sound elicited when bad (loose) roof is tested by striking with a
bar. Hudson

drum pulley

A pulley wheel used in place of a drum. See also:Koepe system
Fay

drum rings

Cast-iron wheels, with projections, to which are bolted the staves or
laggings forming the surface for the hoisting cable to wind upon. The
outside rings are flanged, to prevent the cable from slipping off the
drum. Fay

drum runner

See:incline man

drum separator

A slowly rotating cylindrical vessel that separates run-of-mine coal into
clean coal, middlings, and refuse. It consists of different and adjustable
specific gravities. The low gravity medium in one compartment separates a
primary float product (clean coal), the sink material being lifted and
sluiced into the second compartment where middlings and true sinks (stone)
are separated. Nelson

drum shaft

See:caisson sinking

druse

a. An irregular cavity or opening in a vein or rock, having its interior
surface or walls lined (encrusted) with small projecting crystals usually
of the same minerals as those of the enclosing rock, and sometimes filled
with water; e.g., a small solution cavity, a steam hole in lava, or a
lithophysa in volcanic glass. CF:geode; miarolitic cavity; vug.
AGI
b. A mineral surface covered with small projecting crystals; specif. the
crust or coating of crystals lining a druse in a rock, such as sparry
calcite filling pore spaces in a limestone. Etymol: German. Adj: drusy.
AGI

drusy

a. Pertaining to a druse, or containing many druses. CF:miarolitic
AGI
b. Pertaining to an insoluble residue or encrustation, esp. of quartz
crystals; e.g., a drusy oolith covered with subhedral quartz. AGI

dry

a. Miner's changehouse, usually equipped with baths, lockup cubicles, and
means of drying wet clothing. Pryor, 3
b. A borehole in which no water is encountered or a borehole drilled
without the use of water or other liquid as a circulation medium. Also
called dry hole; duster. Long
c. A borehole that did not encounter a mineral-, oil-, or gas-producing
formation. Also called blank hole; dry hole; duster. Long

dry air

Air with no water vapor. Strock, 2

dry ash-free basis

An analysis expressed on the basis of a coal sample from which the total
moisture and the ash have in theory been removed. BS, 4

dry assay

Any type of assay procedure that does not involve liquid as a means of
separation. CF:wet assay

dry block

The intentional act or process of running a core bit without circulating a
drill fluid until the cuttings at and inside the bit wedge the core
solidly inside the bit. Also called dry blocking. Long

dry blower

See:dry washer

dry blowing

A process sometimes used where water is scarce. The separation of free
gold from the accompanying finely divided material is effected by the use
of air currents. See also:dry cleaning

dry bone

See:dry-bone ore

dry-bone ore

a. An earthy, friable, honeycombed variety of smithsonite in veins or beds in stratified calcareous rocks accompanying sulfides of zinc, iron, and
lead.
b. A variety of hemimorphite. Syn:dry bone