a. A charge that is divided into several separate components along a
quarry borehole. CF:columnar charge
b. A charge separated by stemming. Carson, 1
See:nappe
a. The operation of changing the tubs on a cage at top and bottom of a
shaft. Also called caging. Fay
b. Separating charges of explosives by inert material and placing a primer
in each charge. Nichols, 1
The level at which a cage comes to rest at the pit head and pit bottom for
unloading and loading mine cars. Nelson
A charge of dynamite spaced well apart in a borehole and fired by separate
primers or by a detonating cord. Nichols, 1
A method of loading blast holes in which the explosive charges, called
decks or deck charges, in the same hole are separated by stemming, air
cushion, or a plug. Atlas
Two or more screens, usually of the vibrating type, placed one above the
other for successive processing of the same run of material.
Nichols, 1
In practical mining operations, a term applied to the statutory
certificate of location, and a certificate or statement of the location,
containing a description of the mining claim, verified by the oath of the
locator, performing, when recorded, a permanent function. It is the
beginning of the locator's paper title, is the first muniment of such
title, and is constructive notice to all the world. Ricketts
The efficiency assigned by the maker under certain specified conditions.
Nelson
a. The horizontal angle in any given location between true north and
magnetic north; it is one of the magnetic elements. Syn:variation;
magnetic variation. AGI
b. Angular elevation of a star above celestial equator when truly north of
observer. Pryor, 3
c. Angular deviation of magnetic compass from true north, observed in
conditions where no local deviation affects it. Pryor, 3
d. The angular change in the course of a borehole induced by deflection
techniques, usually expressed in degrees. Long
e. Sometimes a syn. for inclination. See also:inclination
Maps on which isogonic lines are shown. Mason
A conveyor transporting down a slope. See also:retarding conveyor
Detachment structure of strata owing to deformation, resulting in
independent styles of deformation in the rocks above and below. It is
associated with folding and with overthrusting. Etymol: French,
unsticking, detachment. CF:disharmonic folding
AGI
A furnace used in the conversion of common salt into sulfate of soda,
aided by the action of sulfuric acid.
The process of reducing high air pressure gradually enough so as not to
injure people who have been working in it. Nichols, 1
A condition among underwater workers and mine rescue teams that is caused
by ascending too quickly from deep dives.
See:aeroembolism
a. A term sometimes used alternately with ornamental stone.
b. Natural material used as architectural trimmings in columns,
fireplaces, and store fronts; may be set in silver- or gold-filled
jewelry, as curio stones; e.g., malachite and marble. CF:gemstone
A method for decreasing the ground motion generated by an underground
explosion. The method involves the firing of the explosive in the center
of an underground cavity so that the surrounding medium is not in close
proximity to the explosive. Lyman
a. To roast or calcine (as salt) so as to cause crackling or until
crackling stops. Webster 3rd
b. A mineral is said to decrepitate when it flies to pieces with a
crackling noise on being heated. Hess