A device for recording a sonic depth trace. Abbrev., PDR. Hy
A bearing having ground races and in which the bore and outside diameter
tolerances are held to ten-thousandths of an inch and the width tolerance
to thousands of an inch. NEMA, 2
The amount of sensible heat, removed from the air in precooling.
Hartman, 2
Method used in machine mining where a coal cutter makes a cut along the
face in front of a cutter loader. It may be adopted in hard coal seams or
where an improvement in the +2-in (+5.1-cm) coal product is required.
Nelson
A special blade attached to a plow that operates a little in advance of
the main blades of the machine. It may be used in hard coals or to prevent
the climbing of the machine, which would leave a layer of coal on the
floor. Nelson
An index devised by the Medical Research Council of Great Britain which is
based on the rate of loss of sweat from the body. It is designed to
measure the physiological effect of work in near limiting conditions in
hot working places, and is based on the assumption that heat stress is a
function of the rate of sweating. Roberts, 1
An act providing for a patent to agricultural lands. The act does not
include mineral deposits, as they are expressly reserved.
A familiar term under the public land laws meaning exclusive.
Ricketts
a. A name applied to a special type of differential flotation in which a
mixture of two flotative, sulfide minerals is given a slight roast so that
one may be oxidized, and therefore not float, and the other remain
unchanged.
b. Preferential flotation may also be achieved by control of pH or by
addition of an activating agent or depressant to the flotation mixer,
conditioner, or cell. AGI
Applied to froth flotation when separating fine coal from coal washery
slurries. The slurry or mixture is treated with a reagent that has an
affinity for the material to be recovered and that will lend itself to
subsequent stages in the separation process. Nelson
Feature of a rock in which the grains are more or less systematically
oriented by shape. A schist in which the mica plates are parallel to one
another shows a preferred orientation; so does a hornblende schist in
which the long axes of the hornblende crystals are parallel.
See also:orientation; unoriented.
Wire rope in which the strands are bent to their correct lay before being
laid up, so that the rope is unlikely to spin or kink. Pryor, 3
A value-bearing solution in a hydrometallurgical operation.
Pryor, 4
In solvent extraction, the metal-bearing solvent produced in the solvent
extraction circuit.
The liquor resulting from leaching of ore to dissolve a valuable
constituent. Term connotes such a solution when it has reached a loading
sufficient to justify its removal from contact with the ore, for separate
treatment to reclaim the contained values (by precipitation, ion exchange,
or stripping). After this treatment, the now barren solution is returned
to work, or if foul, is run to waste or regenerated. Also called pregnant
solution; royals. Pryor, 3
To heat beforehand; as: (1) to heat (an engine) to an operating
temperature before operation; and (2) to heat (metal) prior to a thermal
or mechanical treatment. Webster 3rd
That portion of a continuous furnace through which the ware passes before
entering the firing zone. ASTM
An orthorhombic mineral, Ca2 Al2 Si3 O10 (OH)
2 , in which Fe replaces Al; forms botryoidal or mammillary and
radiating aggregates. Occurs in: hydrothermal veins, cavities, and
amygdules in basalt; veins in felsic plutonic rocks; and low-grade
metamorphic rocks. Commonly associated with zeolites. Syn:aedelite
a. A variety of mizzonite resembling prehnite. Dana, 1
b. Impure prehnite. Dana, 1
An investigation carried out along certain broad features of a coal or
mineral area, with the object of deciding whether the proposition is such
as to warrant a detailed or final exploration, which is often costly.
Nelson