A machine to jig ore. See also:jig
A screen or pair of screens to which a combined horizontal and vertical
motion is imparted, normally by a crankshaft and connecting rod, the
screen decks being horizontal or inclined at a small angle.
See also:shaking screen
A technique for transferring a surface survey down a mine shaft in such a
manner as to tie it in to an underground mine survey.
See also:coplaning
See:gravity haulage
An apparatus resembling a steam engine indicator; used for drawing curved
lines illustrating the action of jigs in ore beneficiation.
Webster 2nd
A pin used to prevent the turning of the turn beams. Standard, 2
A coal or mineral washer for relatively coarse material. The broken ore,
supported on a screen, is pulsed vertically in water; the heavy (valuable)
portion passes through the screen into a conical receptacle (hutch), and
the gangue goes over the side. In coal washing, the heavy (worthless)
shale passes downwards, and the lighter coal remains on top.
See also:plunger jig washer; jig. Nelson
An orthorhombic mineral, Mn3 B2 O6 ; the manganese
analog of kotoite; with other manganese minerals at the Kaso Mine, Kanuma,
Tochigi Prefecture, Japan.
A portable hand-operated appliance for bending or curving rails. It
incorporates a strong buttress screw thread. Nelson
Underground gravity plane. Pryor, 3
Leic. A short heading along which empties, horses, or workers travel.
Fay
A monoclinic mineral, Ba2 NaCe2 Fe(Ti,Nb)2 Si8
O26 (OH,F).H2 O ; dimorphous with orthojoaquinite; forms
minute honey-colored crystals; with benitoite and neptunite in San Benito
County, CA.
Scot. An iron rod, usually pronged, attached to the rear end of a train of
hutches or cars being drawn up an incline; used to stop their descent in
the event of the rope breaking. Fay
a. Aust. A Y-shaped grip placed in sockets at the end of a skip. The
endless rope rests on this when used above the skip. Fay
b. Mid. A self-acting apparatus on the front of a car, for releasing it
from the hauling rope at a certain point. Fay
a. A joint of trusses or sets of timber for receiving pressure at right
angles or nearly so. Zern
b. Notches cut in round timbers set above other round pieces in
underground timbering. Pryor, 3
c. An offset in a flat plane consisting of two parallel bends in opposite
directions by the same angle. ASM, 1
d. A slight step-shaped offset formed into a flat piece of metal (as for
providing a flange). Webster 3rd
An orthorhombic mineral, CaAlB3 O7 ; forms transparent
grains and lamellar masses; fluoresces an intense blue owing to traces of
rare-earth elements; in nepheline dikes, cutting sandstone in the
Johachido District, Kenkyohokuco Prefecture, Korea.
A triclinic mineral, [Cu(UO2 )2 (SO4 )2 (OH)
2 .8H2 O] ; radioactive; forms soft, bitter-tasting crystals
that are polysynthetically twinned in two directions; in druses and
reniform masses; at Joachimsthal, Czech Republic, and Gilpin County, CO;
associated with gypsum.
A monoclinic mineral, 4[CaMnSi2 O6 ] ; pyroxene group; forms
series with diopside and hedenbergite; shows clove-brown to grayish-green
columnar, radiating, and spherulitic aggregates of fibers and prisms with
black tarnish; in metasomatized limestones with manganese ore. Occurs at
Puebla and Hildago, Mexico; Lane County, OR; Franklin, NJ; and Schio,
Venetia, Italy.
A number, composed of three or four digits, that defines the position of
an igneous rock in Johannsen's classification. The first digit represents
the class, the second the order, and the third and fourth the family.
CF:Johannsen's classification
A quantitative mineralogic classification of igneous rocks developed by
the petrographer Albert Johannsen (1939). CF:Johannsen number
AGI
See:gun