The load expressed in pounds or tons, which, if exceeded, results in the
collapse of a structure, such as a drill tripod, derrick, or A-frame.
Long
a. In a mine shaft, the first wood frame of the shaft; sometimes used in
reference to the mouth or portal of the tunnel. BCI
b. Supporting framework at top of shaft from which linings may be hung.
Pryor, 1
c. The junction of a mine shaft and the surface. Nelson
d. The beginning point of a shaft or drill hole, the surface.
Ballard
e. The mouth of a mine shaft.
f. The bar, or crosspiece, in a framed timber set. Stauffer
g. The term applied to the timbering or concrete around the mouth or top
of a shaft. Lewis
h. Scot. A frame to guide pump rods; the fastening of pipes in a shaft.
i. The mouth or opening of a borehole or the process of starting to drill
a borehole. Long
j. A pipe coupling or sleeve. Long
k. See:friction head
l. A sliding ring mounted on a shaft so that it does not revolve with it.
Used in clutches and transmissions. Nichols, 1
The distance from the top of the powder column to the collar of the
blasthole, usually filled with stemming. Dick, 2
A started hole drilled sufficiently deep to confine the drill bit and
prevent slippage of the bit from normal position.
The act or process of beginning a borehole. Long
a. The process of beginning the drilling of a borehole, or the excavation
of a mine shaft. Long
b. Eng. Timber framing for supporting pump trees in a shaft.
See also:chog
c. The term used to indicate that metal passing through a rolling mill
follows one of the rolls so as to encircle it. CTD
The formation of the front end of a drill hole, or the collar, which is
the preliminary step in drilling to cause the drill bit to engage in the
rock. Fraenkel
A fishtail-, spudding-, or other-type bit used exclusively for beginning a
borehole. Long
In rolling mills, the sections of larger diameter separating the grooves
in rolls used for the production of rectangular sections. CTD
A heavy wooden frame erected at the mouth of a rectangular shaft to
provide a solid support for the timber sets. A more permanent structure
consists of a concrete wall extending from two to eight sets in depth. On
this concrete mass is bolted the bearer timbers that support the top heavy
set or collar set. The term also applies to the heavy concrete ring at the
mouth of a circular concrete-lined shaft. Syn:shaft collar
Nelson
See:ludwigite
A reagent added to a pulp to bring about adherence between solid particles
and air bubbles. BS, 5
That condition in sedimentation in which the particles and flocs are
sufficiently close together to retard the coarse fast-settling particles
while the slow-settling ones are entrapped and carried down with the mass.
Mitchell
A heteropolar compound containing a hydrogen-carbon group and an ionized
group, chosen for ability to adsorb selectively in a froth flotation
process and render adsorbing surfaces relatively hydrophobic. A promoter.
Pryor, 4
a. Strictly speaking, a person who mines coal with a pick, though commonly
applied to anyone who works in or about a colliery. Also called hewer;
stallman.
b. A steam or sailing vessel carrying a cargo of coal.
c. A coal merchant or dealer in coal.
Explosive; used in mines. Bennett
See:anthracosis
a. An entire coal mining plant, generally used in connection with
anthracite mining, but sometimes used to designate the mine, shops, and
preparation plant of a bituminous operation. BCI
b. A coal mine. Pryor, 3
c. A ship, or ships, used in the coal trade. Standard, 2
Derb. The superintendent of the colliery. Fay
That part of the coal output at a colliery that is used for steam
generation and other purposes connected with the working of the colliery
itself. Nelson
An explosion in the workings or roadways of a colliery as a result of the
ignition of combustible gases or coal dust or a mixture of both.
See also:coal-dust explosion; methane; stone-dust barrier.
Nelson