A large-diameter drill with multiple rotary cones or cutting bits used for
shaft sinking. An adaptation from oil well drills. Eng. Min. J., 3
A supply of compressed air at a working pressure of about 100 psi (690
kPa). The quantity required for a modern high-speed sinking may be 2,000
to 2,500 ft3 /min (56.6 to 70.7 m3 /min). At a new mine
where two shafts are being sunk, the power installation may comprise eight
slow-speed water-cooled compressors with a total output of almost 5,000 ft
3 /min (141.5 m3 /min) at 100 psi. Nelson
The ventilation of a sinking shaft is by means of auxiliary fans. Axial
flow fans powered by flameproof motors are commonly used. Nelson
An opening created with the object of relieving pressure on the shaft.
Higham
In anthracite and bituminous coal mining, a laborer who controls the
movement of mine cars as they are run to the top or to the bottom of the
shaft by poking sprags (short metal or wooden rods) between the spokes of
the wheels. DOT
An enlargement of a level near a shaft from which ore, coal, or rock may
be hoisted and supplies unloaded.
A survey to determine the alignment of a shaft.
See:poppet head; headframe; poppet.
N. Staff. Headings driven across the measures from shafts to intersect
inclined seams.
a. The brick or concrete lining in a shaft to support the surrounding
ground. The construction of the permanent shaft wall is normally in
concrete with reinforcement at insets and in bad ground. The wall
thickness is between 12 in and 36 in (30 cm and 91 cm) depending on the
shaft size and water pressure within the strata. Also applied to the rock
masses surrounding the shaft. See also:permanent shaft support
Nelson
b. The side of a shaft.
In the stonework industry, a foreperson who supervises the removal of
waste stone, loading and unloading of finished and semifinished stone, and
the moving and piling of stone slabs and blocks at a stoneworking mill.
DOT
See:relief
a. In a coal mine, a vertical crack in the seam and roof. CTD
b. Fissures in rock. Arkell
c. Minute calcite veins traversing limestone or other rocks containing
carbonates. These veinlets, unlike vents, have no harmful effect on the
building stone. Arkell
d. A cavern, usually in limestone.
e. A close-joint structure in rock, due to natural causes, such as
pressure, weathering, etc. Used in the plural.
A mechanically vibrated screen through which a returning drill fluid is
passed to screen out larger chips, fragments, and drill cuttings before
the drill fluid flows into the sump. Syn:shale screen; shale shaker.
Long
Metal troughs, operated mechanically, for the loading of coal into mine
cars underground. Hudson
a. A conveyor consisting of a length of metal troughs, with suitable
supports, to which a reciprocating motion is imparted by drives. In the
case of a downhill conveyor, a simple to-and-fro motion is sufficient to
cause the coal to slide. With a level or a slight uphill gradient, a
differential motion is necessary; i.e., a quick backward and slower
forward strokes. The quick backward stroke causes the trough to slide
under the coal, while the slower forward stroke moves the coal along to a
new position. Syn:jigger
vibrating conveyor. Nelson
b. A type of oscillating conveyor.
A reciprocating engine operated by compressed air which is used to impart
the reciprocating motion to a shaker conveyor panline. Jones, 1
A screening medium mounted in a rectangular frame, supported in a
horizontal or slightly inclined position, and reciprocated longitudinally
by a crank or eccentric and connecting rod. The unique feature that
differentiates the shaker from all other screens is that the load is made
to travel over the screening medium by the shaking motion of the screen.
Mitchell
A machine for loading coal, ore, or rock usually in headings or tunnels.
It consists of a wide flat shovel that is forced into the loose material
along the floor by the forward motion of the conveyor. The shaking motion
of the conveyor brings the material backwards, and it is loaded into cars
or a conveyor. It works at its maximum efficiency to the rise or in flat
tunnels. Also called duckbill loader. See also:loader
A wave that advances by causing particles in its path to move from side to
side or up and down at right angles to the direction of the wave's
advance, a shake motion. Leet, 1
a. See:springing; shaking a hole.
b. Corn. Washing ore; ore dressing.