The phenomenon sometimes exhibited by refractories containing chrome ore,
when exposed to iron oxide at high temperature, of having the exposed face
swell and grow until it breaks away from the brick mass. ARI
A small charge of fine powder placed in contact with a charge of coarse
powder to ensure the ignition of the latter. Fay
The time between the application of an electric current and the setting
off of an explosive charge. In seismic prospecting, it may be necessary to
take into account the maximum difference in time lag between the bursting
of the earliest and latest detonators in a series. In a series firing
current of over 1 A direct current, the maximum difference with submarine
seismic detonators is always less than 1 ms. Nelson
A stationary, intermittent filter in which the leaves are suspended
vertically in a cylindrical vessel set on a considerable incline. The
leaves are therefore ellipses. The slime cake is discharged by introducing
air and water into the interior of the leaf. There is also a Burt filter
of the continuous-rotating-drum type. Liddell
Any of several arrangements of hoisting tackle; usually one with a single
and a double block. Webster 3rd
A great intrusive igneous body in the Transvaal, South Africa, that has
undergone remarkable magmatic differentiation. It is by far the largest
layered intrusion known. The Bushveld is the leading source of chromite.
AGI
Shaking table for treatment of ore sands, comprising a deck supported by a
Ferraris truss moved by eccentric. Pryor, 3
A triclinic mineral, (Mn,Ca)Si3 O9 .
See:breaking-in shot
Expendable heavy-gage bare copper wire used to connect detonators or
series of detonators in parallel in underground blasting.
Scot. Outward; toward the shaft; outbye.
a. A flammable gaseous hydrocarbon, commonly bottled for use as fuel.
b. A gaseous flammable paraffin hydrocarbon, C4 H10 ,
occurring in either of two isometric forms: n-butane, CH3 CH (sub
2) CH2 CH3 ; or isobutane, CH3 CH(CH3 ) (sub
2) . The butanes occur in petroleum and natural gas. AGI
An instrument giving a continuous record of the methane concentration in
mine air. It uses a small flame burning butane in a gauze-protected
enclosure. Instead of observing the cap, thermocouples are used to show
the increased temperature above the flame, and the resulting signal is
displayed on a recording milliammeter. The instrument runs for at least a
week and is accurate to about 0.05% methane.
See also:methane tester type S
A shaking table, toggle-actuated, with its deck supported in slipper
bearings, and carrying curved riffles. Pryor, 3
Arg. A monoclinic mineral occurring as oriented intergrowths with
parabutlerite. A hydrous sulfate of iron. Am. Mineral., 1
A trigonal mineral, K2 Ca(CO3 )2 ; dimorphous with
fairchildite. Also spelled buetschliite.
a. Opposite of face, coal exposed at right angles to the face, and in
contrast to the face, generally having a rough surface. Also called end in
Scotland. BCI
b. The butt of a slate quarry is where the overlying rock comes in contact
with an inclined stratum of slate rock.
The minor cleat system, or jointing, in a coal seam, usually at right
angles to the face cleat. Syn:end cleat
AGI
a. A conspicuous hill or small mountain with relatively steep slopes or
precipitous cliffs, often capped with a resistant layer of rock, and
representing an erosion remnant carved from flat-lying rocks. The summit
is smaller in extent than that of a mesa; many buttes in the arid and
semiarid regions of the Western United States result from the wastage of
mesas. Syn:mesa-butte
b. An isolated hill having steep sides and a craggy, rounded, pointed, or
otherwise irregular summit; e.g., a volcanic cone (such as Mount Shasta,
CA, formerly known as Shasta Butte) or a volcanic butte. Etymol: French,
knoll, hillock, inconspicuous rounded hill; rising ground. Pron: bewt.
AGI
a. An entry driven at right angles to the butt. BCI
b. The gallery driven at right angles with the butt cleat. An end-on
entry.
c. A gallery driven parallel with the main cleat of the coal seam.
See also:entry
A clear-yellow, rounded segregation of very pure carnotite found in the
soft sandstone of Temple Rock, San Rafael Swell, UT. AGI