a. Removing timber from a mined-out stope to use it again elsewhere.
Stoces
b. Extraction of the pillars of ore left to support workings during
original stoping. Pryor, 3
c. Scot. Reducing the size of pillars; taking as much as possible off
pillars, leaving only what is deemed sufficient to support the roof.
See:drawing an entry
The mining of coal pillars left to support the roof during development
mining, often resulting in cave-ins. See also:working the broken
A heat treatment process carried out in a substantially closed furnace, in
which a fluid fuel is burnt to partial combustion with a gas containing
70% or more of oxygen to produce a nonoxidizing atmosphere. The treatment
is effected continuously in the furnace through which the heating gas and
metal are passed in opposed directions. The fuel and gas are partially
burnt at the exit end of the furnace, and passed to the cooler entry end
of the furnace, and burnt to substantially complete combustion so as to
preheat metal entering the furnace. Osborne
A stacking conveyor system in which material arrives on a conveyor belt
and is fed to one or two wing conveyors. This part of the system moves so
as to form a long ridge; reclaimed by raking gear that works across the
ridge, moving slowly forward and shifting material loosened and blended by
the rake action by means of a spiral that pushes it to a reclaiming
conveyor at the side of the ridge. Used to stockpile ore, concentrates,
and coal. Pryor, 3
A method of obtaining sound steel by fluid compression of the ingot in the
mold. The molds are divided in the center, a removable packing piece being
placed between the halves of the mold. The packing piece is removed when
the metal has set, and the mold is placed horizontally in the press,
pressure being applied to the ingot at both ends. Osborne
A triclinic mineral, Pb4 Sb6 O13 .
A pneumatic loader for inserting cartridges into drill holes.
An early oil flotation process. The oil was added to several times its
weight of ore and mixed in a slowly revolving drum or tube. The process at
one time had quite a large application. The process used but little water
(25% to 30%) and no acid. Fay
Smokeless and flameless safety explosive consisting of ammonium nitrate
and dinitrobenzene or dinitrochloro benzene; used in mines.
Bennett
a. Sp. Rock or stone, whether in the ordinary or geological sense.
b. Sp. Rock standing out from the general surface.
c. Sp. A vein or bed of hard rock and stone.
Fr. Rock, boulder.
a. An aggregate of one or more minerals, e.g., granite, shale, marble; or
a body of undifferentiated mineral matter, e.g., obsidian, or of solid
organic material, e.g., coal. AGI
b. Any prominent peak, cliff, or promontory, usually bare, when considered
as a mass, e.g., the Rock of Gibraltar. AGI
c. A rocky mass lying at or near the surface of a body of water, or along
a jagged coastline, esp. where dangerous to shipping. AGI
d. A slang term for a gem or diamond. AGI
e. Strictly, any naturally formed aggregate or mass of mineral matter,
whether or not coherent, constituting an essential and appreciable part of
the Earth's crust. Ordinarily, any consolidated or coherent and relatively
hard, naturally formed mass of mineral matter; stone. In instances, a
single mineral forms a rock, as calcite, serpentine, kaolin, and a few
others but the vast majority of rocks consist of two or more minerals.
f. A local term used in New York and Pennsylvania for the more massive
beds of bluestone that are not jointed and are, therefore, well-suited for
structural purposes.
g. In the geological sense, any natural deposit or portion of the Earth's
crust whatever be its hardness or softness, but used by miners to denote
sandstone. TIME
h. In geology, the material that forms the essential part of the Earth's
solid crust, and includes loose incoherent masses, such as a bed of sand,
gravel, clay, or volcanic ash, as well as the very firm, hard and solid
masses of granite, sandstone, limestone, etc. Most rocks are aggregates of
one or more minerals, but some are composed entirely of glassy matter, or
of mixtures of glass and minerals. Hunt
i. In the Lake Superior region, crude copper ore as it comes from the
mines. The concentrate obtained is called mineral, and contains about 65%
metallic copper.
See:asphalt rock
a. A group of igneous rocks within a petrographic province that are
related chemically and petrographically, generally in a systematic manner
such that chemical data for the rocks plot as smooth curves on variation
diagrams. See also:tribe
AGI
b. The association of mineral deposits with certain rock types. If
mineral-producing localities are considered individually, valuable
generalizations often can be made, and lithotectonic-plate tectonic
classifications of ore deposits and exploration strategies derived from
them.
See:bedrock
a. Any one of many different types of roller or drill bits used on
rotary-type drills for drilling large-size holes in soft-to-medium-hard
rocks; also sometimes applied to drag-type bits. See also:drag bit;
roller bit. Long
b. In mining, a detachable-type chisel or cruciform bit used on percussive
drills to drill small-diameter holes in rock. Long
c. See:drill bit
A dump body with oak planking set inside a double steel floor.
Nichols, 1
A bar, usually constructed of steel, that is inserted into pre-drilled
holes in rock and secured for the purpose of ground control. Rock bolts
are classified according to the means by which they are secured or
anchored in rock. In current usage there are mainly four types: expansion,
wedge, grouted, and explosive. See also:roof bolt
a. See:roof bolting
b. The process of rock bolting consists of (1) anchoring the bolt in a
hole; (2) applying tension to the bolt to place the rock under compression
parallel to the bolt; and (3) placing the bolts in such a pattern that
they will properly support the rock structure. Rock may be supported by
bolts in five ways: (1) suspension; (2) beam building; (3) reinforcement
of arched opening requiring support; (4) reinforcement of an opening
otherwise self-supporting; and (5) reinforcement of walls against shear
and compressive action. See also:roof bolting
An orthorhombic mineral, (Fe,Mn)Fe4 (PO4 )3 (OH) (sub
5) ; forms a series with frondelite; dark green; named for Rockbridge
County, VA.