A device employed to reduce the number of fuses to be lit by the miner
before retiring to safety. By means of a multifuse igniter, it is possible
to remotely fire stopes or headings primed with plain detonators and
safety fuse. Nelson
Roasting furnace with several hearths vertically superposed. Material is
raked downward by horizontally rotating rabbles, so as to work alternately
to the periphery and center of successive hearths, encountering roasting
heat as it gravitates downward. Pryor, 3
A cutter loader with a number of horizontal jibs similar to a coal cutter.
Loose coal is diverted onto the conveyor by gummer and plow plate. The
machine is usually used in seams up to about 3 ft (0.9 m) in thickness
with a clean roof parting. The depth of cut varies up to 4 ft (1.2 m).
Coal degradation is considerable. Nelson
A bit set with diamonds arranged in successive layers beneath the surface
of the crown. CF:impregnated bit; surface-set bit. Long
Lode that occupies a shear zone. Such a zone has no definite walls, the
ore gradually shading off into country rock. It is probable that the gold
of some rich alluvial fields came from shear zones. Nelson
A dryer whose moving element consists of two strands of roller chain with
specially designed flights, suspended in such a way as to provide means
for keeping the bed in a constantly flowing mass. The material flows in a
shallow bed over the ascending flights and at the same time is gradually
moved across the dryer from the feed point to the discharge point. The
gases are pulled from the furnace and through the flowing bed of coal. The
entire area of the dryer is covered by suction from the exhaust fan.
See also:thermal drying
See:polyphase
A lightweight dam constructed of repeated arches with axes sloping at
about 45 degrees to the horizontal, the arches being carried on parallel
buttress walls. Hammond
The method of quarrying a rock ledge in a series of successive benches or
steps. Fay
Two or more seismic detectors whose combined output energy is fed into a
single amplifier-recorder circuit. This technique is used to cancel
undesirable near-surface waves. Syn:multiple geophones;
multiple recording groups. AGI
A dike made up of two or more intrusions of the same kind of igneous rock.
Billings
A system of access or development openings, generally in bituminous coal
mines, involving more than one pair of parallel entries, one for haulage
and fresh air intake and the other for return air. Multiple-entry systems
permit circulation of large volumes of air.
An engine driven by steam or compressed air expanding in two or more
stages. Hammond
A structure consisting of several parallel faults in close proximity with
no distortion. See also:step fault
Firing electrically with delay blasting caps in a number of holes at one
time. Mitchell
multiple fuse-igniter cartridge
Consists of a cardboard cartridge about 2 in long with a 3/4-in (1.9-cm)
outside diameter. The closed end is coated with black powder, and the ends
of eight fuses are inserted in the cartridge, in contact with the powder.
A master fuse is then inserted, which, when lit, burns to the powder and
ignites it. The powder flares brightly and lights the eight fuses.
South Australia
a. The intercepts that cross a vein, orebody, or other geologic feature,
accomplished by drilling several auxiliary boreholes from a single, main,
or parent borehole with the aid of wedges and similar deflecting devices.
Long
b. Intercepting a steeply dipping vein at various depths by changing the
angle of the drill head.
Any type of igneous intrusion that has been produced by several injections
separated by periods of crystallization. Chemical composition of the
various injections is approx. the same. CF:composite intrusion
AGI
A single line reeved around two or more sheaves so as to increase pull at
the expense of speed. Nichols, 1
Any series of underground openings separated by rib pillars or connected
at frequent intervals to form a system of rooms and pillars. Obert