a. A semi-cylindrical or long, arched oven (usually small and made of
fireclay), heated from outside, in which substances may be exposed at high
temperature to an oxidizing atmospheric current, and kept at the same time
from contact with the gases from the fuel. Cupellation and scorification
assays are performed in muffles; on a larger scale, copper ores were
formerly roasted in muffle furnaces. Fay
b. An enclosure in a furnace to protect the ware from the flame and
products of combustion. ASTM
a. A furnace with an externally heated chamber, the walls of which
radiantly heat the contents of the chamber. McGraw-Hill, 1
b. A furnace in which heat is applied to the outside of a refractory
chamber containing the charge. The charge may be held in a muffle,
crucible retort, or other enclosure that is enveloped by the hot flame
gases, and the heat must reach the charge by flowing through the walls of
the container. CTD; Newton, 1
a. An arched fireclay-lined furnace in which seggars are placed.
CTD
b. A kiln in which combustion of the fuel takes place within refractory
muffles, which, in turn, conduct heat into the ware chamber.
ACSG, 2
A muffler that concentrates on suppressing sound waves vibrating 200 to
2,000 times a second--the loudest and most objectionable ones created by
rock drills. Because the muffler bypasses the lower frequencies, it does
not interfere with the column of air that makes a pneumatic drill
function.
Orthoclase-bearing oligoclase basalt, with major olivine, accessory
apatite, and opaque oxides. Pyroxene may or may not be present.
See also:trachyandesite
a. A small car, or truck, used to push cars up a slope or inclined plane.
Fay
b. See:pusher
c. An extra worker who helps push the loaded cars out in case of an
upgrade, etc.; from Joplin, Mo. Fay
Kansas. An extension bit used in boring coal. Hess
A short length of tubing coupled to the bottom of a drill string to wash
and clean out sand or mud from a borehole, the washing action being aided
by cutting off the bottom end of the tubing at an angle of 45 degrees to
its longitudinal axis. Also called mud socket. Long
A mule driver. Fay
Heavily timbered passage between levels in a mine for the transfer of
unattached mules from one level to the other. Korson
a. Stone, iron shoe, or heavy steel rubbing disk, used to bear down upon
rock in comminution. Pryor, 3
b. A heavy grinding wheel that is the crushing and mixing member in a dry
or wet pan. ARI
c. See:bucking iron
Mixing sand and clay particles by a rolling, grinding, rubbing, or
stirring action. ASM, 1
A wavelike pattern of parallel grooves and ridges, measuring as much as
several feet from crest to crest, and formed on a folded surface or along
a fault surface. CF:slickensides
An orthorhombic mineral consisting of an aluminum silicate that is
resistant to corrosion and heat; used as a refractory. Also known as
porcelainite. McGraw-Hill, 1
See:muck
A machine similar to a dredger used for excavating cuttings for roads,
railways, or canals. One large machine of this type can dig 100 yd/h (91.4
m/h) on a slope 25 ft (7.62 m) high. Hammond
Trade name for a coal-cutter chain designed for use with curved jibs. It
is short pitch and of high flexibility. See also:curved jib
Nelson
A cage containing two or more compartments or platforms to hold the mine
cars supplies or workers. Every effort is made to keep the number of decks
as low as possible for a given output in order to cut down the decking
time and equipment at shaft top and bottom. See also:deck
Nelson
A screen with two or more superimposed screening surfaces mounted rigidly
within a common frame. BS, 5
A sinking platform consisting of several decks to enable various
shaft-sinking operations to be performed simultaneously. The bottom deck,
in a three-deck platform, is usually suspended from four winch ropes which
also act as guides for the kibbles, and the middle and top decks are
supported above the bottom deck by rigid supports. The top deck is used
for the manipulation of the concrete buckets and for fixing the
shuttering. The center deck is used by the workers when placing the
concrete, while the bottom deck carries telephone, blasting, lighting, and
signaling cable drums. The lower side of the bottom deck may carry the
equipment for manipulating the cactus grab. Nelson
Shaking table with two or more superposed decks, independently fed and
discharged but worked by one vibrating mechanism. Pryor, 3