Dynamite containing both ammonium nitrate as the chief explosive
ingredient and a certain percent of blasting gelatin to make it plastic
enough to remain in holes directed upward. It is more resistant to water
than ammonia dynamite, but less resistant than gelatin dynamite.
Lewis
Coal mining that consists of driving cross-measure drifts and developing
of the seams. The roads in the seam are equipped with conveyors for
transporting coal, and locomotives may be used in the cross-measure drifts
when these are horizontal or nearly so. Semihorizon mining may include the
longwall-retreating method. Nelson
Steel that is incompletely deoxidized and contains sufficient dissolved
oxygen to react with the carbon to form carbon monoxide to offset
solidification shrinkage. ASM, 1
In an excavation, both rock that is only partially detached from the solid
and that rings as solid when struck, and rock being still attached to the
solid, but parting from it by incipient shear cracks. Spalding
See:prereduced iron-ore pellet
A furnace with a partial muffle, in which the products of combustion come
in contact with the ware. ASTM
A loosely used term for common opal, hydrophane, and any partly dehydrated
or impure opal, as distinguished from precious opal or fire opal.
Syn:hemiopal
In these types, the quantities of liquid products are insufficient to
render the mixture compressible. When packing cartridges, however, the
same high density is obtained as with plastic explosives. The proportions
of the various constituents are actually so arranged that the spaces
between the grains are filled out. The proportions in question are
determined entirely according to the constituents selected.
Fraenkel
semiportable electric equipment
Electric equipment that is moved infrequently; e.g., room hoists, room
conveyors, and gathering pumps.
Electric lamps that are connected to a fixed source of power by a flexible
cord whose length limits the movable range of the lamp.
Of less commercial value than those called precious; applied esp. to such
stones as amethyst, garnet, jade, and tourmaline. Webster 3rd
A bit-crown design, in which the radius of the arc forming the rounded
portion of the bit face is equal to or greater than the thickness of the
bit wall. Long
Material having a penetration at 77 degrees F (25 degrees C), under a load
of 100 g applied for 5 s, of more than 10; and a penetration at 77 degrees
F, under a load of 50 g applied for 1 s, of not more than 350.
Urquhart
a. Coal intermediate between durain coal and clarain coal (duroclarain).
Tomkeieff
b. A coal in which the proportions of anthraxylon and attritus are more or
less equal, but the attritus of which is essentially composed of brown and
granular opaque matter in varying proportions. Translucent humic matter,
spores, pollens, and finely divided fusain are always present in small
proportions. Also known as block coal. CF:bright coal; splint coal.
Litton
c. A banded coal containing 20% to 30% of opaque attritus and more than 5%
anthraxylon. AGI
A towed vehicle whose front rests on the towing unit. Nichols, 1
A degree of diaphaneity between translucent and opaque. Passes light
through edges of cabochons but very little through thicker parts.
Used to describe mineral when objects may be seen through it but without
distinct outlines.
That degree of vitrification evidenced by a moderate or intermediate water
absorption. Also called semivitrified. See also:impervious; nonvitreous;
vitreous. ASTM
A mixture of carbon monoxide, carbon dioxide, hydrogen, and nitrogen
obtained by passing a mixture of air and steam continuously through
incandescent coke. Its calorific value is low, about 125 Btu/ft3
(4.66 MJ/m3 ). Osborne
A monoclinic mineral, Pb9 Sb8 S21 ; metallic; soft;
sp gr, 5.8.
A trigonal mineral, Pb(Ti,Fe,Mn)21 O38 ; crichtonite group;
black; forms rounded crystals and grains in diamond-bearing sands.