Positive separation at the plane of contact between adjacent structural
components to allow relative movement arising from differences in
temperature or shrinkage. Hammond
A measure of the rate of heat loss from the bulb of the kata thermometer.
Although the cooling power as obtained by this instrument is not a measure
of the capacity of an atmosphere to cool the human body, nevertheless, it
is useful for comparing different atmospheres and provides a convenient
index of the comfort condition of a working place in a mine. Experience
indicates that a face will be reasonably comfortable for working if the
dry kata cooling power is above 7 on the kata thermometer and the air
velocity above 1 m/s. See also:dehumidification; effective temperature.
Nelson
See:playa
The comminution of materials in a suitable mill without the presence of a
liquid, either by rods, balls, or pebbles, or autogenously, by the
material itself; used if the subsequent process is a dry process.
An analysis expressed on the basis of a coal sample from which the total
moisture and the mineral matter have in theory been removed. BS, 4
a. In dry mining every effort is made to prevent the ventilating air
picking up moisture, and throughout the ventilation circuit there is a
wide gap between wet- and dry-bulb temperatures. Dry-bulb temperatures are
therefore comparatively high. Spalding
b. Refers to the reasonably dry footing required for the equipment. Dry
stripping and placer mining with standard earthmoving heavy equipment
depends on good footing for the equipment and short hauls to keep costs in
line. Syn:dry diggings
Said of lead or copper ore that contains precious metals (gold and silver)
but insufficient lead or copper to be smelted without the addition of
richer ore. See also:natural ore
Gold-bearing alluvial deposit found in arid regions. In some deposits the
gold is in the cementing material that binds the gravel together. Because
of the lack of water, various machines have been devised for the dry
washing of these deposits; such machines commonly include some form of
pulverizer and jigs or tables that use compressed air instead of water in
their operation. Also called desert placer. Lewis
a. A method of treating ores by heat as in smelting; used in opposition to
wet process, where the ore is brought into solution before extraction of
the metal. See also:wet process
b. The process of making Portland cement in which the raw materials are
ground and burned dry. Mersereau, 2
c. Process whereby dry powdered enameling materials are applied to a
preheated surface. Van Vlack
d. The method of preparation of a ceramic body wherein the constituents
are blended dry, following which liquid may be added as required for
subsequent processing. ASTM
A process of decarbonization on a siliceous hearth in which the conversion
is effected rather by the flame than by the reaction of solid or fused
materials. As the amount of carbon diminishes, the mass becomes fusible
and begins to coagulate (come to nature), after which it is worked
together into lumps (puddle balls, loups) and removed from the furnace to
be hammered (shingled) or squeezed in the squeezer, which presses out the
cinder, etc., and compacts the mass at welding heat, preparatory to
rolling. Silicon and phosphorus are also largely removed by puddling,
passing into the cinder. See also:puddling
See:dry drilling
To unknowingly or knowingly drill with a bit when the flow of the coolant
and cuttings-removal fluid past the bit has been inadvertently or
deliberately cut off. CF:dry drilling
A sample obtained by drilling procedures in which water or other fluid is
not circulated through the drill string and sampling device; hence the in
situ characteristics of the sample have not been altered by being mixed
with water or other fluid. CF:drive sample
Various auger and/or tubular devices designed to obtain unwetted samples
of soft rock material, such as clay, sand, soil, etc., by drilling
procedures wherein water or other fluid is not circulated during the
operation. Long
a. A stratum of dry sand or sandstone encountered in well drilling. A
nonproductive sandstone in oilfields. Fay
b. Green sand dried in an oven to remove moisture and strengthen it (a
dried-sand mold is a mold of green sand that is treated as above).
Freeman
The screening of solid materials of different sizes without the aid of
water. BS, 5
a. The elimination of the small pieces of shale, pyrite, etc., from coal
by a blast of air directed upon the screened coal.
See also:wind method
b. See:dedusting
A process by which impure blister copper is exposed to long oxidizing
heating below fusion point. Standard, 2
The weight of soil solids per unit of total volume of soil mass. Also
called unit dry weight. See also:unit weight
Thin-bedded limestone or sandstone suitable only for mortarless (dry)
fencing or retaining walls.
A wash that carries water only at infrequent intervals and for short
periods, as after a heavy rainfall. CF:arroyo