a. A gate for shutting out, admitting, releasing, or otherwise regulating
a body of water, such as excess water in times of flood; specif. the lower
gate of a lock. See also:sluice
b. A stream stopped by or allowed to pass by a floodgate. AGI
The surface or strip of relatively smooth land adjacent to a river
channel, constructed by the present river in its existing regimen and
covered with water when the river overflows its banks. It is built of
alluvium carried by the river during floods and deposited in the sluggish
water beyond the influence of the swiftest current. AGI
See:flucan
a. The rock underlying a stratified or nearly horizontal ore deposit,
corresponding to the footwall of more steeply dipping deposits.
b. The bottom of a coal seam or any other mineral deposit. CF:roof
Arkell
c. Plank-covered, or steel-mesh-covered, level work area at the base of a
drill tripod or derrick around the collar of a borehole in front of the
drill. See also:platform
d. Loose plank laid parallel with rock drift at the heading before
blasting a round of holes to facilitate the loading of broken rock.
e. A horizontal, flat orebody.
f. The bed or bottom of the ocean. A comparatively level valley bottom;
any low-lying ground surface. AGI
g. That part of any underground gallery upon which a person walks or upon
which a tramway is laid.
h. A plank platform underground.
i. The upper surface of the stratum underlying a coal seam. CTD
The break or crack that separates a block of stone from the quarry floor.
Also called floor cut. Hess
A type of outburst generally occurring in longwall faces and preceded by
heavy weighting due to floor lift. Gas that evolved below the seam seems
to collect beneath an impervious layer of rock, and a gas blister forms
beneath the face, giving the observed floor lift. Later, the floor
fractures and the combustible gases escape into the mine atmosphere.
See also:outburst
a. A machine cut made in the floor dirt immediately below the coal seam.
See also:undercutting; bottom cut. Nelson
b. A cut by means of which a block of stone is separated from the quarry
floor. See also:floor break
The upward heave of the floor beds after a coal seam has been extracted.
See also:creep
A large timber laid flat on the ground or in a level, shallow ditch to
which are fastened the drill-platform boards or planking. Long
A survey station secured in the floor of a mine roadway or working face.
BS, 7
An automatic gate used in placer mining when there is a shortage of water.
This gate closes a reservoir until it is filled with water, when it
automatically opens and allows the water to flow into the sluices. When
the reservoir is empty the gate closes, and the operation is repeated.
See also:boomer
The entire plant population of a given area, environment, formation, or
time span. CF:fauna
A trigonal mineral, (La,Nd,Ce)Al3 (PO4 )2 (OH) (sub
6) ; crandallite group; further speciated according to which rare-earth
element predominates; weakly radioactive; pale yellow; in schists,
carbonatites, pegmatites, and placer sands.
See:fluorite
An arborescent variety of aragonite occurring in delicate white coralloid
masses that commonly encrust hematite, forming picturesque snow-white
pendants and branches.
White cast iron for converting into steel. Webster 2nd
a. A small door provided at the bottom of a flue or chimney for ash
removal. Osborne
b. A tap hole. Fay
a. Ore lying between the beds or at certain definite horizons in the
strata. Arkell
b. Eng. Veins that branch off laterally, Alston Moor lead mines.
Arkell
a. See:froth flotation
of reagents floats some finely crushed minerals, whereas other minerals
sink. Formerly the term flotation with descriptive adjectives was used for
all processes of concentration in which levitation in water of particles
heavier than water was obtained. Thus, if some particles were retained in
an oil layer or at the interface between an oil layer and a water layer,
the process was spoken of as bulk-oil flotation; if the particles were
retained at a free water surface as a layer one particle deep, the process
was skin flotation; and if the particles were retained in a foamy layer
several inches thick, the process was froth flotation. Froth flotation is
the process that has survived the test of time, and the term flotation is
now used universally to describe froth flotation.
See also:bulk oil flotation; film flotation; selective flotation;
skin flotation. Syn:flotation process
A substance or chemical that alters the surface tension of water or that
makes it froth easily. See also:surface activity; depressant.
Nelson
Appliance in which froth flotation of ores is performed. It has provision
for receiving conditioned pulp, aerating this pulp and for separate
discharge of the resulting mineralized froth and impoverished tailings.
Types of cell include (1) agitation (impeller, and splashing, now
obsolete); (2) pneumatic (in which air blown in agitates pulp), such as
Hallimond laboratory cell, Callow, McIntosh, Forrester, Southwestern, and
Britannia; (3) vacuum cells (Elmore and Clemens, obsolescent); (4)
subaeration with mechanized stirring and pressure-input air (M.S. cell,
Agitair); (5) subaeration, self-aerating mechanized cell (Fagergren,
Denver, M.S.S.A., Humboldt, Boliden, K.B., etc.) Pryor, 3