A quarryman's hammer for striking a rock drill. Standard, 2
Two horizontal timbers separated by striking wedges and supporting an arch
center. The latter is lowered by slacking the wedges. Stauffer
A dilute solution of silver cyanide, containing potassium cyanide, in
which articles to be silver-plated are dipped before being immersed in the
silver bath proper. Standard, 2
a. Drilling bit, jars, drill stem, rope socket, and other tools connected
to the lower end of a drilling cable in standard or percussion drilling.
Also used for the rig and complete drilling equipment. Syn:drill string;
string of tools. AGI
b. A measurement of depth of a drill hole obtained by stringing over the
length of cable from the drilling floor to the crown pulley on top of the
derrick or mast. AGI
c. A very small vein, either independent or occurring as a branch of a
larger vein; a stringer.
a. A mineral veinlet or filament, usually one of a number, occurring in a
discontinuous subparallel pattern in host rock. See also:stringer lode
AGI
b. A thin layer of coal at the top of a bed, separating in places from the
main coal by material similar to that comprising the roof.
c. A heavy timber or plank, usually horizontal but sometimes inclined,
supporting other members of a structure; also, the horizontal crosspiece
in square set timbering.
d. See:roof stringer
A small orebody--generally, a vein leading to a more valuable one.
AGI
A shattered zone containing a network of small nonpersistent veins.
Syn:stringer zone
Mine timbering in which the caps reach across two or more sets in a drift
or stope. Hess
See:stringer lode
Filling a drill hole with cartridges smaller in diameter than the hole,
without slitting or tamping them. Nichols, 1
a. In a churn drill, the tools suspended on the drilling cable.
Nichols, 1
b. The entire downhole drilling assembly. See also:string
a. A rough method of transferring points from upper to lower levels in
very narrow steep workings by suspending strings from point to point and
measuring offsets. The excavation dimensions may be similarly obtained.
See also:plumbing
b. The use of stretched strings in awkward underground workings to provide
survey lines and a basis for offsets. In the lost-thread method of survey,
a string or thread is paid out over a measuring device as a traverse line
is walked. Pryor, 3
a. In mining, to remove the earth, rock, and other material from the
mineral to be mined, usually by power shovels. Generally practiced only
where the mineral lies close to the Earth's surface. BCI
b. To remove from a quarry, or other open working, the overlying earth and
disintegrated or barren surface rock. See also:baring
c. To mine coal, alongside a fault, or barrier.
d. To fill prepared coal from a coal face. See:stripping
Syn:stripping a mine
a. A heavy medium process developed in Sweden for concentrating iron,
copper, and chromite ores. The rate of supply of water over a shaking bed
of wet sand effects the separation of heavy and light fractions.
b. A method of gravity treatment of coarse sands, in which feed is shaken
along horizontal launder and at the same time kept in teeter by hydraulic
water. Constituent minerals stratify into separable layers.
Pryor, 3
A skid- or crawler-mounted drill operated by electric motor or diesel
engine. It is used at quarry or opencast sites for drilling horizontal
blast holes 3 to 6 in (7.6 to 15.2 cm) in diameter, and up to 100 ft (30
m) in length, without the use of flush water. It cannot penetrate strong
strata. Nelson
The series of bands of variation in color or texture in a rock mass, or
the course of the planes of such bands, as indicative of the course of the
bedding plane when that is otherwise obscure. See also:ribbon
Standard, 2
Trademark for a dynamite for coal stripping operations. CCD, 2
A stripping; an opencut mine in which the overburden is removed from a
coalbed before the coal is taken out. See also:opencast; opencut;
openpit mine. Hess
The mining of coal by surface mining methods as distinguished from the
mining of metalliferous ores by surface mining methods; the latter is
commonly designated as openpit mining. See also:opencast method;
openpit mining; surface mining. Woodruff
An arrangement of alternate packs and wastes built in a direction parallel
to the gate roads in longwall conveyor mining. A common practice is to
allow 5-yd (4.5-m) wastes between 4-yd (3.7-m) packs, or both are made 5
yd wide. The dimensions vary with local conditions.
See also:stowing method; double packing; single packing. Nelson
See:degraded illite