a. A single-bucket excavator in which the bucket travels along the boom,
which is kept almost horizontal during operation. Dodd
b. An excavator base machine equipped with jib and bucket for digging and
loading from a shallow face above track level. Nelson
A digging bucket mounted to slide along the boom of an excavator so that
the bucket can be used to trim various angles of slope from the horizontal
to about 60 degrees elevation. Hammond
The removal of the top layer of soil or of irregularities in the ground
surface at new mine or opencast sites. See also:skimping
Nelson
A channel in a sand mold having over it a bridge that removes the dross
from the molten metal as it passes through. See also:skimmer
Standard, 2
Any ladle used in skimming; specif., a ladle used for pouring molten
metal, having its lip covered with a guard to retain the dross.
Standard, 2
a. The skimmings of the dross from the ore in the vat or tank.
Nelson
b. See:jigging
a. Tendency of an alternating current to concentrate at the surface of a
conductor. Schieferdecker
b. The frequency-dependent reduction of resistivity log measurements in
conductive formations due to inductive interaction between the current
paths; the induction logs now operating at about 20 kHz are most affected.
AGI
c. The reduction of formation permeability in the vicinity of a well bore
caused by drilling and completion operations. AGI
d. The concentration of alternating current in a conductor towards its
exterior boundary. AGI
a. A concentration process in which adhesion is effected between a free
water surface and particles, usually larger than those involved in froth
flotation. Gaudin, 1
b. In skin flotation processes, the separation between minerals and gangue
is accomplished at the surface of a body of water, or, in other words, at
the air-water interface. Use is made of the surface tension of the water
and of the fact that certain minerals, such as sulfides and hydrocarbons,
resist being wetted by water. See also:flotation
a. Friction between a fluid and the surface of a solid moving through it,
or between a moving fluid and its enclosing surface. Webster 3rd
b. The frictional resistance developed between soil and a structure.
ASCE
c. Resistance of ground to the movement of a pile or caisson, generally
proportional to the area in contact. Hammond
d. See:wall friction
The thin band of rock immediately surrounding an excavation.
Spalding
a. A guided steel hoppit, usually rectangular, with a capacity up to 50 st
(45.4 t), which is used in vertical or inclined shafts for hoisting coal
or minerals. It can also be adapted for personnel riding. The skip is
mounted within a carrying framework, having an aperture at the upper end
to permit loading, and a hinged or sliding door at the lower end to permit
discharge of the load. The cars at the pit bottom deliver their load
either directly into two measuring chutes located at the side of the shaft
or into a storage bunker from which the material is fed to the measuring
chutes. Nelson
b. A large hoisting bucket, constructed of boiler plate that slides
between guides in a shaft, the bail usually connecting at or near the
bottom of the bucket so that it may be automatically dumped at the
surface.
c. An open iron vehicle or car on four wheels, running on rails and used
esp. on inclines or in inclined shafts. Sometimes spelled skep.
d. A thin slice taken off a breast, pillar, or rib along its entire length
or part of its length. Also called slab.
e. A truck used in a mine. Gordon
f. A small car that conveys the charge to the top of a blast furnace.
Mersereau, 2
The tub or bucket used for containing the material conveyed by a skip
hoist.
A method of underground haulage sometimes adopted in steep workings, where
the gradient is 1:2 to 1:1.5. There are two kinds: (1) a skip carriage on
which the tub is placed in a horizontal position; and (2) a self-dumping
system in which the skip, which is permanently attached to the rope, is
discharged automatically at the top of the incline and then returned for
reloading. Nelson
A bucket or car operating up and down a defined path, receiving,
elevating, and discharging bulk materials.
In metal mining, one who loads ore into a skip (large can-shaped
container) from skip pockets (underground storage bins) at different shaft
stations in a mine, operating a mechanical device to open and close the
gates of the loading chutes. Also called skipman; skipper. DOT
In bituminous coal mining, one who drills holes into pillars of coal
supporting the roof, charges holes with explosives, and blasts out slabs
(skips) of coal to widen haulageway or working place. DOT
In the iron and steel industry, one who controls the skip hoist by which a
skip car containing coke, limestone, or ore is hauled up an inclined
runway to the furnace top and dumped into the charging bell of the
furnace. DOT
The working of 2 to 10 yd (1.8 to 9.1 m) of coal along the side or sides
of a narrow stall or heading to gain coal and make room for ripping stone.
See also:rib-side pack
a. To take a slice off a pillar before abandoning the workings; to rob.
Fay
b. Widening a gangway or entry. Fay
A mine shaft esp. prepared for hauling a skip. Standard, 2
A system used for moving material from a quarry floor to a plant located
at a considerable elevation. This system utilizes two parallel inclined
tracks with a skip car operating on each track. The cars are operated by
cables controlled by a winding gear at the head of the incline. The quarry
trucks or cars deliver their loads to the skips through a chute at the
base of the incline. A hopper at the top of the incline receives the loads
from the skips and feeds the rock to a crusher. Pit and Quarry