Long-handled, plierlike device similar to a certain type of blacksmith
tongs used to handle wash or drill rods in place of a safety clamp in
shallow borehole drilling. Syn:brown tongs; knife dog.
Scot. The lower portion of a seam of coal that is worked in two sections
or leaves. Fay
The smallest quantity of combustible gas that, when mixed with a given
quantity of air (or oxygen), will just support a self-propagating flame.
Francis, 2
In soil mechanics, the moisture content at which soil changes from plastic
to liquid. Pryor, 3
Moisture content of soil at which it changes from a plastic to a semisolid
state. Pryor, 3
See:footwall
Common division of the color scale--about 887 degrees F (475 degrees C).
An explosive in which the change into the gaseous state is effected by
burning and not by detonation as with high explosives. Blasting powder
(black powder or gunpowder) is the only low explosive in common use. It
requires no detonator but is ignited by means of a safety fuse. Also
called propellant. Nelson
Dynamites made by replacing part of the nitroglycerin of straight
dynamites with some ingredient to render the dynamite incapable of
freezing under ordinary conditions of use. The freezing point is depressed
by adding nitro substitution compounds, such as nitrated sugars,
nitrotoluene, nitrated polymerized glycerin, or ethylene glycol dinitrate.
Lewis
See:polar explosive
a. See:slow gear
b. Mining and/or drilling operations carried on at a leisurely pace and at
less-than-normal output per worker shift. Long
c. When applied to a screwfeed-type drill, the pair of feed gears in the
feed mechanism that advances the bit the least amount for each revolution
of drill drive rod and/or coupled drill stem.
d. When applied to speed at which the drill motor rotates the drill stem,
the transmission-gear position giving the lowest number of bit revolutions
per minute per engine revolutions per minute; corresponds to low gear in
an automobile.
a. An arbitrary designation of dynamites of less strength than 40%. It has
no bearing on the quality of the materials, as they are of as great purity
and high quality as the ingredients in a so-called high-grade explosive.
Fay
b. Sometimes applied to poor- or low-quality drill diamonds. Long
c. Pertaining to ores that have a relatively low content of metal compared
with other richer material from the same general area. Also designates
coal high in impurities. Low-grade metamorphism refers to metamorphism at
a relatively low temperature and/or pressure. CF:high-grade
Stokes
d. See:lean ore
Combustible material that has only limited uses owing to undesirable
characteristics (for example, ash content or size). BS, 5
A cement in which there is only limited generation of heat during setting,
achieved by modifying the chemical composition of normal portland cement.
Hammond
A clay that fuses between 1,520 degrees C and 1,590 degrees C.
Osborne
A burned magnesite brick, containing 90% or more of magnesia, and 1.5% to
2.5% iron oxide.
Scot. The drift or working that is farthest to the dip; also called laigh
level.
In uranium leach treatment, the bulk of the barren solution after some
75,700 L of high-nitrate solution have been run through the ion-exchange
(IX) column. Low in nitrate and uranium and contains some backwash water.
Pryor, 3
Explosives containing a small portion of nitroglycerin and a base similar
to blasting powder. Intermediate between blasting powder and dynamite in
action. See:low-grade
The filling of the waste by means of compressed-air blower. The blower is
usually located close to the stowing machine and operated at a pressure
below 15 psi (103.4 kPa). For light duties, only one blower is required to
operate one stowing machine. For heavier work, or very long lengths of
pipeline, two blowers are used in series. The maximum horsepower for two
blowers in series does not commonly exceed 200 (149 kW) at large
installations. See also:pneumatic stowing
The lowest pressure at which flame propagation can be obtained through a
combustible-oxidant system at a fixed temperature in a particular chamber.
Van Dolah