The inner barrel assembly of a wire-line core barrel, designed for
removing core from a borehole without pulling the rods. Long
A catch ring on a retractable wedge that engages a lifting device on the
deflection barrel or bit, enabling the drill runner to remove a deflecting
wedge from a borehole after deflection has been effected. Long
The mineralogical adjustment of relatively high-grade metamorphic rocks to
temperatures lower than those of their initial metamorphism,
characteristically inducing hydration and hydrous minerals.
Syn:retrogressive metamorphism; diaphthoresis.
CF:prograde metamorphism
a. Any airway in which vapid air flows from the workings to the upcast
shaft or fan. See also:intake
b. Any airway which carries the ventilating air from the face outby and
out of the mine. BS, 8
c. Any surface turned back from the face of a principal surface.
ACSG, 1
d. The rate of profit in a process of production per unit of cost.
Webster 3rd
a. Air traveling in a return. BS, 8
b. Air that has circulated the workings and is flowing towards the main
mine fan; vitiated or foul air. Nelson
c. Air returning to a heater or conditioner from the heated or conditioned
space. Strock, 2
Portion of ventilation system of mine through which contaminated air is
withdrawn and evacuated to surface. Pryor, 3
That portion of a circulated drill fluid flowing from the face of a bit
toward the collar of a borehole. CF:return water
Charge made per unit of ore or concentrate treated by smelter in custom
smelting. In addition to a basic charge that allows for process costs and
agreed percentage loss in recovery, extra charges may be specified, or
remitted as premiums, in adjustment of variations from the normal makeup
of the parcel treated. Pryor, 3
The water, mud, or other circulated medium reaching the borehole collar
after having been circulated past the drill bit. Long
A tester developed by the U.S. Bureau of Mines for detecting and
controlling corrosion in steam-condensate-return lines of large heating
plants. This tester determines types and rates of corrosion and can
distinguish among various possible causes. It is assembled from ordinary
black iron pipe nipples and couplings, the linings are easily machined,
and the corroded linings can be analyzed quickly in any laboratory.
In anthracite coal mining, one who resets timbers, shovels up falls of
slate, rock, or dirt, and keeps in general repair the airways by which
mine air returns to the surface. DOT
a. The drill fluid and entrained sludge that overflows the collar of a
borehole. Long
b. In seismic reflection prospecting, the signals reflected back to the
surface from layer boundaries in the subsurface.
c. Also used in geophysical prospecting to register passage of waves
caused by detonation of dynamite. Hess
Drill fluid that reaches the surface and overflows the borehole collar
after it has been circulated downward through the rods and past the drill
bit. Long
An orthorhombic mineral, (Mn,Mg)2 (Ce,La,Nd)(AsO4 )(OH) (sub
4) ; speciated on the basis of predominance of cerium, lanthanum, or
neodymium; in dolomite cavities in Sweden.
An impure Glauber's salt (mirabilite), found native. Standard, 2
A resinlike, reddish-brown oxygenated hydrocarbon, soluble in boiling
alcohol and in ether. Found in certain coal deposits.
An impure, hydrous nickel silicate from Revda (Revdinsk), Ural Mountains,
Russia. Also spelled revdinite, revdinskite, rewdinskit, rewdanskite;
rewdjanskit, and refdanskite. English; Hey, 1
The process of restoring or replacing the botanical species upon an area
disturbed by mineral operations. Revegetation is a customary requirement
for reclamation of a mineral operation. SME, 1
a. To deflect flame or heat, as in a reverberatory furnace. Fay
b. To reduce by reverberated heat; to fuse. Fay