A crushing machine consisting of a rotating cylinder with a corrugated or
toothed outer surface that crushes material by pinching it between the
teeth and stationary breaking bars. CF:double-roll crusher
ACSG, 2
See:Koepe sheave
A system of underground haulage in which a single rope is used, the empty
trip running in by gravity. Engine-plane haulage.
The cross-sectional view of the cutting-face portion of a core bit when
the profile is an arc having a radius equal to or greater than the wall
thickness. See also:profile
The drilling, charging, and firing of a single row of vertical holes along
a quarry or opencast face. The holes may be fired simultaneously or by
delay detonators to give a peeling action starting at one end of the face.
See also:multiple-row blasting
A charge in one drill hole only fired at one time, as contrasted with a
multiple shot where charges in a number of holes are fired at one time.
A single-shot blasting unit is a unit designed for firing only one
explosive charge at a time. Syn:blasting unit
Exploders of the magneto type that are operated by the twist action given
by a half-turn of the firing key. A magneto exploder consists essentially
of a small armature that can be rotated between the poles of a set of
permanent magnets. The armature is rotated by means of toothed gear wheels
actuated by the movement of the firing key. The electric circuit between
the exploder and the detonator is completed by means of an automatic
internal switch operating at the end of the stroke, or contact may be made
by means of a pushbutton. McAdam, 2
A borehole surveying instrument that records only one measurement of the
bearing and of the inclination of a hole on a single trip into the
borehole. Long
A borehole survey made with a single-shot instrument. Long
A sling that has a single hook at one end and an iron or steel ring at the
other. See also:two-leg sling
single-speed floating control system
In flotation, floating control in which the manipulated variable changes
at a fixed rate, increasing or decreasing depending on the sign of the
actuating signal. Fuerstenau
One of three recognized methods of determining the average velocity of
airflow along a mine roadway by anemometer. A velocity reading is taken at
the center of the airway and the result is multiplied by the center
constant, whose value ranges between 0.8 and 0.9, to give the average
velocity of flow. Alternatively, the reading is taken along a midway line
at a position some one-seventh to one-third of the width of the airway,
measured from the side. At this position, the mean velocity is obtained,
so that no adjustment is required. CF:division method;
traversing method. Roberts, 1
A centrifugal pump with a lift of 100 ft (30.5 m) per stage.
Hammond
See:room-and-pillar
a. A mill possessing batteries of one stamp each, like the Nissen, instead
of the usual five.
b. A mill possessing only one stamp, after the Lake Superior fashion,
where one big stamp does the work of 150 ordinary gravity stamps.
Fay
A jaw crusher with one jaw fixed, the other jaw oscillating through an
eccentric mounted near its top. This type of jaw crusher has a relatively
high output, and the product is of fairly uniform size. Dodd
A longwall conveyor face from about 80 to 200 yd (73 to 183 m) long
developed between two gate roads, one serving as an intake airway and
usually for coal haulage, while the other acts as a return airway and for
bringing in supplies to the face. See also:double-unit conveyor
Nelson
A single ore deposit of identical origin, age and character throughout. A
single small vein is weighed and measured by the same law and entitled to
the same consideration as the mother lode, and very often is far more
valuable in the eyes of the miner. Ricketts
A slag with a silicate degree of 1. Newton, 1; Newton, 2