Coal that does not form cake; namely hard, splint, cherry, and durain
coal. Tomkeieff
Any of several stoping methods, including open stopes, sublevel,
shrinkage, cut-and-fill, and square set. Lewis
A mine in which the material being mined is incombustible or contains at
least 65% by weight of incombustible material, and in which the
underground atmosphere in any open workings contains less than 0.25% by
volume of flammable gas. CFR, 2
A bituminous coal that burns freely without softening or any appearance of
incipient fusion. The percentage of volatile matter may be the same as for
coking coal, but the residue is not a true coke. Fay
Any material that will neither ignite nor actively support combustion in
air at 1,200 degrees F (649 degrees C) when exposed to fire.
See also:incombustible
Pertaining to the stratigraphic relations shown by a nonconformity.
AGI
a. An unconformity developed between sedimentary rocks and older rocks
(plutonic igneous or massive metamorphic rocks) that had been exposed to
erosion before the sediments covered them. The restriction of the term to
this usage was proposed by Dunbar & Rodgers (1957). Although the term is
well known in the classroom, it is not commonly used in practice (Dennis,
1967). AGI
b. A term that formerly was widely, but is now less commonly, used as a
syn. of angular unconformity, or as a generic term that includes angular
unconformity. Term proposed by Pirsson (1915). AGI
nonconsumable-electrode arc melting
A method of arc melting in which a carbon or tungsten electrode is used
and the sponge metal to be melted is fed into the arc at the proper rate.
Newton, 1
See:plug bit
Drilling a borehole without taking core. Long
A general type of bit made in many shapes that does not produce a core and
with which all the rock cut in a borehole is ejected as sludge. Used
mostly for blasthole drilling and in the unmineralized zones in a borehole
where a core sample is not wanted. Also called blasthole bit; plug bit.
CF:fishtail bit; roller bit. Syn:blind bit
Methods of examination, usually for soundness, which do not involve
destroying or damaging the material or part being tested. It includes
radiological examination, magnetic inspection, etc. Also called
nondestructive inspection. Rolfe
A rotary or percussive-type drill equipped with core-cutting tools or
bits, the cutting points of which are not inset with diamonds.
Long
The firing of one or more charges using safety fuse, igniter cord,
detonating cord, shock or gas tubing, or similar nonelectric materials to
initiate a blasting cap. Syn:nonel
shock tube system. Federal Mine Safety
nonelectric delay blasting cap
A detonator with an integral delay element and capable of being initiated
by miniaturized or regular detonating cord. CFR, 1
Of, or relating to, a metal or compound that does not contain appreciable
quantities of iron; ores that are not processed primarily for their iron
content.
Specif., an alloy containing no iron. Generically, any alloy that has as
its base any element other than iron. Common commercial nonferrous alloys
are based upon aluminum, copper, lead, magnesium, nickel, tin, and zinc.
Henderson
That branch of metallurgy that deals with the broad field of metals other
than iron, or alloys other than of iron base. CF:ferrous metallurgy
Henderson
a. Classification of metals that are not commonly associated with alloys
of iron, including base metals, precious metals, and light metals.
b. In singular form, an alloy that has as its base metal a metal other
than iron, e.g., copper, lead, aluminum, etc.
A well that yields water at the ground surface only by means of a pump or
other lifting device. See also:artesian well