A multiple-deck roasting furnace of the annular type; used in Germany.
Fay
Mechanism for control of rate of feed of coarse ore in the primary and
secondary crushing system. Several heavy loops of chain lie above and bear
on ore that rests in the delivery chute at just above its natural angle of
repose. When the shaft from which the loops are suspended is rotated by
its small motor, ore slides under control. Pryor, 3
An American variety of hearth for the treatment of galena, differing from
the Scotch hearth in using wood as fuel, working continuously, and having
hollow walls, to heat the blast. Fay
A scale for rating earthquake effects. Devised in 1878 by de Rossi (Italy)
and Forel (Switzerland). No longer in general use, having been supplanted
by Wood and Neumann's Modified Mercalli intensity scale of 1931.
AGI
A brown to garnet-red resinous material forming lenticular masses in the
coal of Carusthia. AGI
A tapered float rises or falls in a transparent tube in accordance with
the velocity of the rising liquid. Variations include spinning floats and
magnetic or radioactive ones for use with opaque fluids. Rate-of-flow
indicator. Pryor, 3
Laboratory screen shaker widely used in screen sizing analysis. Up to
seven 8-in round screens are nested on the appliance and given a shaking,
rotary, and tapping motion. Pryor, 3
See:rotary table; rotary-drill rig.
As used in a broad sense by drillers, a roller bit. Long
A system of boring, using usually hollow rods, with or without the
production of rock cores. Rock penetration is achieved by the rotation of
the cutting tool. The method is used extensively in exploration,
particularly when cores are required. It is the usual method in oil well
boring with holes from 6 to 18 in (15 to 45 cm) in diameter.
See also:boring; diamond drilling; rotary drill. Nelson
A breaking machine for coal, rock, or minerals. It consists of a trommel
screen with a heavy cast steel shell fitted internally with lifts that
progressively raise and convey the coal and stone forward and break it. As
the material is broken the undersize passes through the apertures, so that
excessive degradation does not occur. See also:trommel;
Bradford breaker. Nelson
A rotary-type drill on which a rotary bucket is fastened to the kelly bar.
The bucket is equipped with a hinged bottom, which has straight-edged
cutting blades or teeth. When rotated by the kelly bar, the bucket loads
from the bottom; when filled, it is withdrawn from the hole and dumped by
unlatching the bottom. Holes 30 to 250 cm in diameter can be drilled with
this machine in soft, boulder-free ground. Also called bucket rig;
dry-hole digger; rathole rig. See also:bucket drill
A compressor designed for a delivery pressure of 100 psi (690 kPa) and
ranging in capacity from 60 to 300 ft3 /min (2.1 to 8.5 m (super
3) /min). See also:air-conditioning process
A drier in the shape of an inclined rotating tube used to dry loose
material as it rolls through. ACSG, 2
Broadly, various types of drill machines that rotate a rigid, tubular
string of rods to which is attached a bit for cutting rock to produce
boreholes. The bit may be a roller cone bit, a toothed or fishtail drag
bit, an auger bit, or a diamond bit. See also:core drill; rock drill.
CF:diamond drill; shot drill.
The chips and pulverized rock produced by the abrasive and chipping action
of a drag, roller bit, or diamond bit when used on a diamond- or
rotary-drill machine to drill a borehole. CF:cuttings
The hydraulic process of drilling that consists of rotating a column of
drill pipe, to the bottom of which is attached a drilling bit, and during
the operation, circulating down through the pipe a current of mud-laden
fluid, under pressure, by means of special slush pumps. The drilling mud
and cuttings from the bit are forced upward and outside the drill pipe to
the surface. CF:cable-tool drilling
The space available in the casing of a pneumatic rotary rock or coal drill
is necessarily limited and precludes the use of a reciprocating engine.
The power unit used instead is similar in design to the vane compressor.
The rotor runs at a very high speed, between 3,500 rpm and 4,000 rpm, and
this is reduced by gearing to give a drill spindle speed of about 650 rpm.
A rotary drill complete with accessory tools and equipment necessary to
drill boreholes. Long
An apparatus for overturning one or more mine cars simultaneously to
discharge coal. They may rotate either 180 degrees or 360 degrees .
BCI
A standard small car in which the car body, of about 2 yd3 (1.5 m
3 ) capacity, is mounted on a turntable in the car frame. The car
body may be swung by hand to dump over either side or either end.
Pit and Quarry