Aust. A bin in which fine coal (slack) is stored.
In metal smelting, the scoria of previous operations, mixed with the ores
to retard or prevent fusion of the nonmetallic portions. Also spelled
slakin. Standard, 2
In bituminous coal mining, one who hauls small cars of slack (fine coal)
from tipple to boiler room of power plant at mine to maintain fuel supply.
DOT
a. Degradation in size (coal). Bennett
b. Coals having a pronounced tendency to disintegrate or slack on exposure
to weather, particularly when alternately wetted and dried or subjected to
hot sunshine. Coals that slack readily contain relatively large amounts of
moisture. When exposed to the weather, such coals lose moisture rapidly.
As the coal loses moisture at the surface, the moisture from the interior
of the piece gradually drifts outward to the surface. If the loss of
moisture at the surface proceeds at a faster rate than that at which it is
replaced by moisture from the interior of the piece, then the shrinkage of
the coal at the surface is greater than that in the interior;
consequently, stresses are generated in the surface coal. These stresses
cause the coal to crack and disintegrate. Also called weathering.
See also:weathering; weathering index. Mitchell
See:weathering index
a. A cableway having one low and one high tower and a track cable with
adjustable tension suspended between them. One end of the track cable is
attached to a hoist drum by means of which the tension on the cable can be
rapidly changed so as to position, lower, or raise the digging skip.
b. A cable excavator having a track cable that is loosened to lower the
bucket and tightened to raise it. Nichols, 2
The process of hardening steel by quenching from the austenitizing
temperature at a rate slower than the critical cooling rate for the
particular steel--resulting in incomplete hardening and the formation of
one or more transformation products in addition to or instead of
martensite. ASM, 1
The state of a tidal current when its velocity is near zero, the moment
when a current reverses direction. Sometimes considered the intermediate
period between ebb and flood currents during which the velocity of the
currents is less than 0.1 knot (0.16 km/h). Hy
a. Material from the iron blast furnace, resulting from the fusion of
fluxstone with coke ash and the siliceous and aluminous impurities
remaining after separation of iron from the ore. Slag is also produced in
steelmaking. Formerly a solid waste, slag is now utilized for various
purposes, chiefly in construction. AGI
b. A scoriaceous or cindery pyroclastic rock. AGI
c. A British term for a friable shale with many fossils. AGI
d. A substance formed in any one of several ways by chemical action and
fusion at furnace operating temperatures: (1) in smelting operations,
through the combination of a flux, such as limestone, with the gangue or
waste portion of the ore; (2) in the refining of metals, by substances
such as lime added for the purpose of effecting or aiding the refining; or
(3) by chemical reaction between refractories and fluxing agents, such as
coal ash, or between different types of refractories.
Harbison-Walker
e. Partially fused mixture of spilled batch, overflowed glass, breeze
coal, and clay from the siege. ASTM
f. The top layer of the multilayer melt formed during some smelting and
refining operations. In smelting, it contains the gangue minerals and the
flux; in most refining operations, the oxidized impurities. CTD
g. Oxide liquids (exclusive of the commercial glasses) with a high melting
temperature. Van Vlack
h. See:blast-furnace slag; granulated slag.
The coating of slag, or scum, that forms on the top of the bath in the
open-hearth furnace. Mersereau, 2
A very large pot for holding slag obtained in the smelting or ores. It is
mounted on a railway truck or the like, so as to permit easy dumping.
See also:slag pot
Iron vessel on wheels used to transport molten slag from furnace to dump.
Also called slag buggy. Pryor, 3
A dumping place for the shell or cone that forms in a slag pot.
Standard, 2
Capable of becoming or forming into a slag. Fay
Destructive chemical reaction between refractories and external agents at
high temperatures, resulting in the formation of a molten liquid.
Henderson
Destructive chemical reaction between refractories and external agencies
at high temperatures, resulting in the formation of a liquid.
A hearth, on the principle of the Scotch hearth, for the treatment of
slags, etc., produced by lead smelting in the reverberatory furnace. The
English slag hearth has one tuyere; the Castillian or Spanish, three.
Fay
Slag (dross) entrapped in a metal. ASM, 1
Lead obtained by a resmelting of gray slag. Fay
A vessel for the disposal of slag at furnaces. Small pots are mounted on
wheels and moved by hand, while the larger ones are mounted on trucks for
mechanical transportation. See also:slag buggy; slag car. Fay