A nonpersistent vein that is wide above and narrow below, and that
terminates within the formation it traverses. The term was originally
applied to vein fillings in vertical solution joints in limestone.
AGI
Conversion of coal to gaseous fuel without leaving a combustible residue.
BS, 4
The setting on fire of a small or large accumulation of combustible gases
in a coal mine. The ignition may be caused by a safety lamp, electrical
machinery, explosives, frictional sparking, etc.
Syn:ignition of combustible gases
A pocket device for the rapid determination of the percentage of a
specific gas in the atmosphere of mines, boiler rooms, blast furnaces,
etc. Fay
Rock formations, usually in coal mines, that contain a relatively high
proportion of methane. In descensional ventilation, the buoyancy pressure
of the methane opposes the ventilating pressure, with a tendency for
cavities to contain combustible gases of high concentration. The same may
apply to waste cavities with no natural exit to the return. Nelson
An underground official who examines the mine for combustible gases and
has charge of their removal. See also:fire boss; gas watchman.
Hess
a. Mid. A short wooden pipe about 4 in by 4 in (10.2 cm by 10.2 cm)
inside, having its upper end open to the roof, and the lower end opening
into the bratticing so that any gas given off in the roof may be carried
away as formed. Fay
b. Any pipe for conveying gas. Fay
A cavity in the rocks containing gas, generally above an oil pocket.
Mersereau, 2
A gas bubble in a mineral. Standard, 2
The forces generated from the expansion of gases formed from the reaction
of explosive materials after detonation; gas pressures produce the heaving
action during rock blasting. Syn:borehole pressure
A furnace in which coal is burned for the manufacture of producer gas.
There are two types: (1) the step-grate, natural-draft generator, which is
but a development of the ordinary firebox; and (2) the shaft furnace, with
or without a grate and worked by a natural or forced draft. The latter
type is identical in many respects to a blast smelting furnace.
Fay
The ratio of the volume at atmospheric pressure of the gas developed by an
explosive to the volume of the solid from which it was formed. Many
commercial explosives have a gas ratio of about 8. Ammonium nitrate plus
fuel oil has a ratio of about 20. Leet, 2
In the iron and steel industry, one who reverses gas valves by
manipulating levers to throw hot combustion gases from one side of the
furnace to the other, to keep the furnace heat evenly distributed, and to
prevent burning out on one side. DOT
A borehole drill, either rotary or churn-drill type, driven by a
combustion-type engine using a combustible liquid, such as gasoline, or a
combustible gas, such as bottle gas, as the source of the motivating
energy. Long
a. Absorption of gas by a metal. ASM, 1
b. Evolution of gas from a metal during melting operations or on
solidification. ASM, 1
c. The evolution of gas from an electrode during electrolysis.
ASM, 1
A process that denotes the brittleness produced when copper containing
oxide is heated in an atmosphere containing hydrogen. The hydrogen
diffuses into the metal and combines with oxygen, forming steam that
cannot diffuse out. A high steam pressure is built up at the crystal
boundaries, and the cohesion is diminished. CTD
a. The spectrum, consisting of bright lines or bands, obtained by
dispersing the light from a glowing gas or vapor. Webster 2nd
b. An absorption spectrum obtained by passing light through a gas or
vapor. Webster 2nd
A process of magmatic differentiation involving the formation of a gaseous
phase, usually during a late stage in consolidation of the magma, that
results in partial expulsion, by escaping gas bubbles, of residual liquid
from the crystal network. AGI
A mine is said to be gassy when it gives off methane or other gas in
quantities that must be diluted with pure air to prevent occurrence of
explosive mixtures. BCI
Slowly moving air currents can be directly observed by using smokes. These
may range from simple dust clouds, through various chemical smokes, to
more refined techniques employing gas and radioactive tracers. Various
chemicals have been used, including stannic chloride, titanium
tetrachloride, and pyrosulfuric acid. These materials give off white fumes
when their vapors come into contact with atmospheric moisture. The method
in common use is to carry the chemical in sealed glass ampules, which can
be broken when an observation is to be made. Roberts, 1
One of many devices for separating and saving the gas from the flow and
lead lines of producing oil wells. The mixture of oil and gas is allowed
to flow through a chamber large enough to reduce the velocity of the
mixture to the point at which the oil and gas tend to separate. The gas,
seeking the top of the chamber, is drawn off free of oil, while the oil is
discharged at the bottom. Also called gas tank. Ash