An extrusive rock similar in composition to a leucitophyre but containing
haueyne in place of some of the leucite. Other possible phases include
nepheline, augite, magnetite, apatite, melilite, and mica. A partial syn.
of haueynitite; some rocks are called haueynophyre when haueyne is a
conspicuous mineral but not necessarily a major constituent.
See also:haueynitite
Every crystal of precise chemical structure and purity has a specific and
characteristic shape. Pryor, 3
A double furnace for the distillation of zinc wherein waste heat from one
set of retorts is utilized for heating the second set. Fay
A gem-quality variety of olivine (forsterite) in Hawaii; forms phenocrysts
in basalt; also in derived sands.
a. A gem variety of olivine from the lavas of the Hawaiian Islands. It
contains little iron and is pale green.
b. As defined by Iddings in 1913, an olivine basalt with andesine as the
normative plagioclase (thus differing from true basalt, in which the
normative plagioclase is more calcic). It generally, but not always, lacks
normative quartz, and commonly contains normative and modal olivine.
Hawaiite is intermediate in composition between alkali olivine basalt and
mugearite, and grades into both. See also:mugearite; trachybasalt.
AGI
A transparent colorless quartz containing closely packed, parallel fibers
of crocidolite that impart to it a blue color. In form and sheen, it
resembles tigereye to which it alters geologically. Differs from sapphire
quartz, in which fibers are not parallel. Also spelled hawkeye.
CF:tiger's-eye
An isometric mineral, CdS ; sphalerite group; dimorphous with greenockite;
occurs as yellow powder on sphalerite.
A large rope, varying from 5 to 24 in (12.7 to 61.0 cm) in circumference,
of 6 to 9 strands and left-handed twist. Standard, 2
a. Of fiber rope, one with three strands of yarn twisted left-handed,
these strands being laid up right-handed. Pryor, 3
b. If wire rope, it is called cable laid. Pryor, 3
A series method of electrolytic refining. Unrefined copper anodes are
suspended in an acid electrolyte; one side of each then acts as an anode
and the other as a cathode. Pryor, 3
This projector can be made at any colliery workshop from a few short
pieces of piping and an old oil drum. It may be fixed in the drum or in an
open tank of larger capacity placed 12 to 15 yd (11.0 to 13.7 m) back from
the face of the hard heading. To the water in the drum, powdered washing
soda is added at the ratio of 4 oz (113.4 g) to 5 gal (18.9 L) of water.
About 2 min before firing, compressed air is turned on and ejections of
water in the form of a coarse mist fill the heading. This continues for a
period of 6 min after the firing. In this manner, the heading is filled
with a mist of droplets that outnumber the dust particles; the latter are
effectively wetted or become attached to the droplets, with the result
that the dust rapidly settles out of the air. This mist projector has a
high efficiency, particularly where the ventilation current is low.
Mason
N. of Eng. In coal mining, a tough mixture of sandstone and shale; also,
freestone, flagstone, or chert.
A method for casting liquid metal or steel continuously into rolls for
sheet or plate. The steel is poured on to the outer surface of a broad
steel cylinder of very large diameter (up to 6 m) that is supported and
revolved by a roller turning inside it. The molten steel is carried a
short distance to a roller revolving above the ring, which rolls the
almost solidified steel into a thin plate or strip. Osborne
a. Any road, level, or other passage driven in coal, etc., for the purpose
of proving and working the mine.
b. The top portion of a seam in the coal face. CTD
c. The whole falling unit in a stamp battery, or merely the weight at the
end of the stem. CTD
d. The top end of the boring rods above the surface.
e. Core-barrel head.
f. In gravity separation of a feed, the heads are the concentrates.
Opposite of tail. Pryor, 3
g. Variously used as a syn. for core-barrel head; drill head; swivel head.
Long
h. The attitude or direction in a massive crystalline rock along which
fracture is most difficult. It is normal to the grain and rift.
i. The difference in air pressure producing ventilation. CTD
j. In mineral processing, the mill head, or grade of ore, accepted by the
mill for treatment. Commonly used in the plural.
k. The height of water above any point or plane of reference. Used also in
various compounds, such as energy head, entrance head, friction head,
static head, pressure head, lost head, etc. Seelye, 1
l. A unit of pressure intensity usually given in inches or feet
(millimeters or meters) of a column of the fluid under consideration.
Thus, 1 ft (or m) of water head is the pressure from a column of water 1
ft (or m) high. Strock, 2
m. The upper bend of a fold or structural terrace. CF:foot
Syn:upper break
n. An advance main roadway driven in solid coal. CTD
o. Development openings in a coal seam. Pryor, 3
p. Total head (th). Also called head on pump.
q. So. Staff. A shift or day's work by the stint in heading-out, or
driving of dead work. Fay
r. To cut or otherwise form a narrow passage or head. Fay
s. A lift. Fay
t. As applied to rock, natural planes of cleavage at right angles to the
grain and the rift of the rock. Stauffer
u. Rubble drift on the cliffs of southern England. Standard, 2
A timber set under the walking beam to prevent it from falling on members
of the drilling crew when it is disconnected. Williams
a. A stop at the head of a slope or shaft to stop cars from going down the
shaft or slope. Fay
b. A cap piece. Fay
c. A heavy obstruction placed end-on across the rail to prevent the
passage of a runaway mine car. Hudson
d. The crosstie that supports the toes of the switch. Zern
e. Commonly used as a syn. for crown block; sheave wheel. Long
a. A wedge of wood placed against the hanging wall, and against which one
end of the stull is jammed. Zern
b. A horizontal board in the roof of a heading, touching the earth above
and supported by a headtree at each side. Hammond
A device for distributing a suspension of solids in water to a machine at
a constant rate, or for retarding the rate of flow, as to a top-feed
filter or for eliminating by overflow some of the finest particles.
BS, 5
Scot. Formerly, the stratum of a coal next to the roof. More usually now,
the top portion of a coal seam when left unworked, either permanently or
afterwards taken down; the top coal on a loaded wagon. Fay
a. Usually the ultimate delivery end of a conveyor.
b. That part of a mining belt conveyor that includes the head section, a
power unit, and, if required, the connecting section and a belt takeup.
NEMA, 2
a. Pieces of plank--longer than a cap--extending over more of the roof and
supported by two props, one at each end. Ricketts
b. An entry-boring machine, called a road header, which bores the entire
section of the entry in one operation. Fay
c. The person in charge of driving a heading. CTD
d. A rock that heads off or delays progress. Fay
e. A blasthole at or above the head. Fay
f. A masonry unit laid flat with its greatest dimension perpendicular to
the face of the wall; generally used to tie two wythes of masonry
together. ACSG, 1
g. A large pipe into which one set of boilers is connected by suitable
nozzles or tees, or similar large pipes from which a number of smaller
ones lead to consuming points. Headers are essentially branch pipes with
many outlets, which are usually parallel. Strock, 1