An appliance for controlling mine cars at loading points, for marshalling
trains, and for loading cars into cages, tipplers, and other points. It
consists of a carrying chain running between the rails. The dummy or live
axles of the cars are held firmly by the chain's profile, and an overload
slipping action is provided. See also:feeder
An overhead cavity caused by a fall of roof. Nelson
a. S. Wales. An old or disused heading over the top of another one.
Fay
b. N. of Eng. See:lacing
c. Scot. Wood filling up vacant space on top of crowns or gears.
Fay
d. Timbers, usually old, laid across the caps of steel frames or sets in a
working to support the roof. Webster 2nd
The record of, or the process of recording, events or the type and
characteristics of the rock penetrated in drilling a borehole, as
evidenced by the cuttings, core recovered, or information obtained from
electric, sonic, or radioactivity devices. Also called logged; logging.
See also:well log
This machine consists essentially of two horizontal cutting chains, one
working at the base of the coal seam and the other at a distance from the
floor; a third cutter chain is mounted vertically on a shearing jib at
right angles to the other two and shears off the coal at the back of the
cut. The upper jib breaks the coal up into loadable size, and a short
conveyor transfers it to the face conveyor. Similar in principle to the
A.B. Meco-Moore cutter-loader. Mason
A book in which the official record of events or the type and
characteristics of the rock penetrated by the borehole is entered. Also
called journal; journal book. CF:log
A chain composed of links of round bar pieces curved and welded to
interlock, with a grabhook at one end and a round hook at the other.
Nichols, 1
Tongs with end hooks that dig in when the tongs are pulled.
Nichols, 1
A slightly slanting trough in which revolves a thick shaft or log,
carrying blades obliquely set to the axis. Material is fed in at the lower
end, water at the upper. The blades slowly convey the lumps of material
upward against the current, while any adhering clay is gradually
disintegrated and floated out the lower end. Liddell
A process by which a protective zinc coating is amalgamated to a
base-metal sheet. Liddell
A term proposed by Shrock (1947) for a residual surficial layer produced
by intense and prolonged chemical weathering and composed largely of
certain original constituents of the source rock. Typical accumulations of
loipon are the gossans over orebodies, bauxite deposits in Arkansas, terra
rossa deposits of Europe, and duricrust of Australia. Etymol: Greek,
residue. Adj: loiponic. AGI
Variety of bituminous material derived from a mud volcano.
Tomkeieff
a. An orthorhombic mineral, 2[FeAs2 ] ; basal cleavage; metallic;
sp gr, 7.45; in quartz veins; a source of arsenic. Also spelled
loellingite, lollingite. Syn:leucopyrite; glaucopyrite; geyerite.
b. The mineral group costibite, loellingite, nisbite, rammelsbergite,
safflorite, and seinaejokite.
A term used in the Southwestern United States for an elongated, gentle
swell or rise of the ground (as on a plain), or a rounded, broad-topped,
inconspicuous hill. Etymol: Spanish, hillock, rising ground, slope.
AGI
A triclinic mineral, Na2 Ti2 Si2 O9 .Na (sub
3) PO4 ; in alkalic pegmatites and sodalite syenites; Kola
Peninsula, Russia.
A direction of less than 45 degrees to the main natural line of cleat or
cleavage in the coal. Also spelled horn. CF:short awn
A highly plastic clay. Syn:fat clay
A column that fails by buckling, as distinct from crushing, when
overloaded. CF:short column
Underground boreholes and blastholes exceeding 10 ft (3.05 m) in depth or
requiring the use of two or more lengths of drill steel or rods coupled
together to attain the desired depth. CF:long-hole drill
Method of blasting, employing diamond drills or extension steel drills
with tungsten carbide bits, applied to ore-winning operations where
conditions are suitable. The essential requirements from the practical and
economic points of view are (1) a large orebody or wide regular vein, (2)
a strong country rock, and (3) a good parting between the ore and the rock
to avoid undue contamination of the ore. Holes to take cartridges up to 2
in (5.1 cm) in diameter may be drilled. Since the drilling of long holes
is relatively expensive, high-strength, high-density gelatinous explosives
are usually employed so that the maximum burden can be placed on each
hole. For this reason also, the largest diameter of explosive cartridge
that can be loaded into the holes should be used to obtain the greatest
possible loading density. McAdam, 2
A rotary- or percussive-type drill used to drill underground blastholes to
depths exceeding 3 m. CF:long hole