The separation of powder into particle-size fractions by means of a gas
stream of controlled velocity. ASTM
Coke formed in gas retorts as distinguished from that made in a coke oven.
Webster 3rd
A pipe for leading combustion gases from the mouth of a blast furnace to a
hot-blast stove. Fay
A system for initiating blasting caps in which the energy is transmitted
through the circuit by means of a gas detonation inside a hollow plastic
tube. See also:nonelectric blasting; shock tube system. Dick, 2
a. Eng. A heading driven in a mine for the special purpose of carrying off
methane from any workings.
b. A tunnel or borehole for conducting gas away from old workings.
CTD
The release of gas from the strata into the mine workings. BS, 8
The quantity of methane discharged from the strata and coal seams into the
ventilating air of a coal mine. The rate may be expressed on a time or
tonnage basis. Gas emission varies with (1) the rate of advance of the
workings; (2) the face operation such as cutting, blasting, loading, etc.;
and (3) the barometric reading. Nelson
See:gas bubble
a. Having the form of or being gas; of or relating to gases.
Webster 3rd
b. Lacking substance or solidity. Webster 3rd
A method of isotope separation based on the fact that atoms or molecules
of different masses will diffuse through a porous barrier at different
rates. The method is used to enrich uranium with the uranium-235 isotope.
Lyman
A dispersion pattern that may be detected by analysis of soil, air, or gas
dissolved in underground water, or of gas condensed in the rocks and soil.
Gaseous dispersion patterns of interest include those of hydrocarbons and
some noble gases resulting from nuclear decay of radioactive elements, and
gaseous substances such as Hg, H2 , He, SO2 , CO2 ,
and CS2 . Hawkes, 2; Lewis
Includes natural gas and the prepared varieties, such as coal gas, oil
gas, and iron blast furnace gas, as well as producer gas, etc.
Newton, 1
A place that is likely to be dangerous from the presence of flammable gas.
Fay
Separation from a magma of a gaseous phase that moves relative to the
magma and releases dissolved substances, usually in the upper levels of
the magma, when it enters an area of reduced pressure. AGI
The liberation of gas in the form of bubbles during the solidification of
metals. It may be due to the fact that the solubility of a gas is less in
the solid and liquid metal respectively, as when hydrogen is evolved by
aluminum and its alloys, or to the promotion of a gas-forming reaction, as
when iron oxide and carbon in molten steel react to form carbon monoxide.
See also:blowhole; unsoundness. CTD
A major or minor explosion of combustible gases in a coal mine, in which
coal dust apparently did not play a significant part.
See also:coal-dust explosion
The combustion of coal effected by burning in such a way as to produce a
combustible gas, which is then burned secondarily in the laboratory or the
furnace. Fay
Coal containing 35% to 40% volatiles (dry, ashless basis).
Tomkeieff
a. The addition of gaseous materials as a flux to promote melting.
b. A rapid upward streaming of free juvenile gas through a column of
molten magma in the conduit of a volcano. The gas acts as a flux to
promote melting of the wall rocks. AGI
Hills and valleys in electrolytic deposits caused by streams of hydrogen
or other gas rising continuously along the surface of the deposit while it
is forming. Henderson
A small-scale tension fracture that occurs at an angle to a fault and
tends to remain open. AGI