Materials placed in stopes for the purpose of ground control, that is to
arrest or regulate the closure of the walls. Spalding
A measuring weir having its sides flush with the sides of the channel, so
that there are no end contractions. Hammond
A pattern of fold in which there is thickening at the synclinal troughs
and thinning at the anticlinal crests. It is formed by differential
compaction on an uneven basement surface. CF:similar fold;
parallel fold. AGI
a. Any load including earth that is supported above the level of the top
of a retaining wall. See also:relieving platform;
active earth pressure. Hammond
b. The algebraic sum of the losses and gains of a cornet of gold during
cupellation and solution. Fay
a. The top of the ground. As used in the conveyance of coal in place, or
in a conveyance of land reserving the minerals, includes not merely the
surface within the boundary lines, without thickness, but includes
whatever earth, soil, or land lies above the superincumbent upon the coal
or mineral reserved.
b. See:cover; drift; mantle; overburden.
c. In geology, usually refers to (1) the boundary surface between one bed
or mass of rock and another immediately adjacent, such as a bedding
surface, a fault surface, a surface of unconformity, a surface of igneous
compact, or (2) an imaginary surface, such as the axial surface of a fold.
Challinor
Any kind of action that affects a surface; e.g., action of smoke fumes,
moisture, etc., on a painted surface. Crispin
Chemical compound that modifies physical, electrical, or chemical
characteristics of surface of solid, also surface tensions of solids or
liquids. Used in froth flotation and in detergency. Characteristically,
its heteropolar molecules are attracted to a specific type of surface in a
mixture where one group forms polar monolayer attachments while the rest
of the molecule points outward and changes the relations between the
surface and the ambient phase. These relations may change lyophilic and
aerophilic attraction, surface tension, intermiscellar grouping,
emulsification, and froth foaming. Surface-active agents include cleaners
(e.g., soaps); water repellants (e.g., greases); dispersants and
emulsifiers (e.g., glue); and additives adsorbed at interfaces between
liquids (usually aqueous) and external gas, liquid or solid phases, with
resulting change in interfacial tension. Three electrochemical types are
unionized molecule, anion, and cation. Important characteristics of
surface-active agents are solubility in the medium and effects of specific
adsorption at interfaces. Such agents either provide anchorage between
phases or form a barrier, according to their flocculating or dispersing
effect. Pryor, 3
The property possessed by certain solid substances to influence the
surface tension of liquids. See also:depressant; flotation agent;
surface tension. Hammond
The amount of surface air entering a fan through the casing at the top of
the upcast shaft, the airlock doors, and the fan-drift walls. The extent
of leakage will depend on the fan-drift water-gage method of construction,
the number and type of entrances, and whether the upcast shaft is used for
winding. The surface leakage at airlocks may vary from about 25,000 ft
3 /min (708 m3 /min) at 5-in (12.7-cm) water gage to
about 55,000 ft3 /min (1,557 m3 /min) at 25-in (63.5-cm)
fan-drift water gage. See also:volumetric efficiency
Of a particle, area calculated from data obtained by a specified method,
such as: (1) adsorption measurement, (2) calculation, (3) permeability
measurement, (4) microscopic observation, or (5) close screening and
averaging from study of a number of particles. Pryor, 3
See:surface damage
A large capacity hopper or standage room to store coal or mineral coming
from the winding shaft. The provision tends to equalize the run of mine
going to the preparation plant and smooth out any minor breakdowns in the
plant. Nelson
All expenses incurred on the surface of a mine that have to be charged
against the mineral.
The mine car track layout from the shaft to the preparation plant and back
to the shaft. The term includes all the equipment necessary to move and
control the movement of cars, such as creepers, retarders, back shunts,
traversers, and turntables. Nelson
An unconsolidated, unstratified clay occurring on the surface.
ASTM
The heat transmitted from (or to) a surface to (or from) the fluid in
contact with the surface in a unit of time per unit of surface area per
degree temperature difference between the surface and fluid. Measured in
units of watts per square meter Kelvin. Strock, 2
a. Any damage done to land surface during mine exploration or development
operations. Syn:surface break
b. Scot. Ground occupied and damaged by colliery operations; the
compensation for such.
a. Orebody that is exposed and can be mined from the surface. Zern
b. See:superficial deposit
The covering of an existing surface with a coating of bituminous binder
covered by a layer of chippings or fine aggregate. Nelson
A drift (usually inclined) from the surface to the coal seam or orebody to
be developed. See also:drift mining; slant. Nelson
Boreholes collared at the surface of the Earth, as opposed to holes
collared in mine workings or underwater. See also:surface rig
Long