A track layout for rail or road transport from large opencast pits. The
track is arranged spirally along the steep rise from the coal or ore
benches so that the gradient is moderate throughout. Nelson
Trade name for a cutter loader incorporating a special variety of shearer
head. The Mark II model consists of section plates welded together to form
a composite whole spiral. The disk is made in different sizes to give
cutting diameters of from 31 to 72 in (79 to 183 cm) with a maximum web
depth of 30 in (76 cm). A single spiral is used for softer coals and a
double spiral for hard coals. A plow attached to the machine throws the
coal onto the conveyor. Nelson
A device to withdraw broken rods from a borehole. It is lowered down the
hole and the screw is turned around until it grips the broken rod below
the joint. See also:wad hook; wad coil. Nelson
A kind of fuse. The tube carrying a train to the charge in a blasthole.
Also called reed or rush, because these, as well as spires of grass, are
used for the purpose. See also:reed
A helmet in which the crown and frontpiece are blocked out of rawhide, and
the front shield is fitted with two mica windows in hinged aluminum
frames. It has a twin-tubed air feed on each side of the helmet and a
valve for the escape of excess and vitiated air. Air is supplied through
an armored hose from double-acting bellows or a blower worked by a second
person at the fresh air base. Airtightness is obtained by means of a soft
leather apron secured in position about the neck and shoulders.
Illumination is provided by portable electric lamps, and communication
with the wearer by an approved type of mine telephone.
Sinclair, 1; Mason
Acetic acid obtained by distilling copper acetate.
a. Nitric acid. Osborne
b. A solution of ethyl nitrite in alcohol. Osborne
Sulfurous acid. Osborne
Acetic acid. Osborne
Dilute acetic acid. Osborne
Ethyl alcohol. Osborne
Methyl alcohol. Osborne
A monoclinic mineral, (Mn,Zn)2 Te3 O8 ; red to
purple.
Slow-burning fuse that has been cut open at the lighting end for ease of
ignition. A small quantity of the plastic explosive used in the hole is
sometimes inserted in the cut. Pryor, 3
a. Lighting the fuse for a blast.
b. An action of or appearance on the surface of slowly cooled, large
masses of melted silver or platinum, in which the crust is forcibly
perforated by jets of oxygen, often carrying with them drops of molten
metal. Also called sprouting. Standard, 2
A rock mass under stress that ejects small fragments with considerable
velocity on breaking.
A series of hopper-shaped or pointed boxes for separating mineral-bearing
slimes according to fineness, in which the width of each box is double
that of its predecessor, while the lengths increase by arithmetical
progression. As used in flotation, it is the froth-separating compartment
of mechanical-agitation-type flotation machines. Also called spitz.
See also:funnel box
Hydraulic classifiers shaped like the spitzkasten, but having provision
for pressure water to flow upward from near the apex, thus improving
efficiency of separation. Pryor, 3
a. A plate lined with firebrick and placed over the iron trough next to
the taphole to keep down flame that blows from the taphole during a cast.
Fay
b. A water spray system for the protection of the metal structure
immediately above the tapping hole during the tapping of a blast furnace.
Henderson
A laborer who shovels charcoal over the surface of molten copper being
poured from a reverberatory furnace into a tilting ladle to prevent excess
oxidation of metal. DOT
One of a series of divergent small faults at the extremities of a major
fault. Splays are typically associated with rifts.