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blanket shooting

Applied to a method of blasting on a face not exceeding 30 ft or 35 ft
(9.1 m or 10.7 m) in height. It involves leaving at the quarry face a mass
of shattered rock several feet in thickness that serves as a buffer,
preventing the rock from being thrown far from its source, and also
rendering the shot more effective. Syn:buffer shooting;
shooting against the bank. Fay

blanket sluice

A sluice in which coarse blankets are laid to catch the fine but heavy
particles of gold, amalgam, etc., in the slime passing over them. The
blankets are removed and washed from time to time to obtain the precious
metal. Fay

blanket strake

A trough over which gold pulp flows. It is lined with a blanket for
catching coarse gold and associated minerals. See also:strake
Nelson

blanket vein

A horizontal or sheet deposit. See also:blanket; blanket deposit.
CF:bed vein

blanket washer

In ore dressing, smelting, and refining, one who cleans flannel blankets
over which a mixture of finely ground gold ore and cyanide solution from
Chilean mills is passed to collect free particles of gold not dissolved by
the cyanide. DOT

blank hole

a. A borehole in which no minerals or other substances of value were
penetrated. Syn:barren hole; dry hole. Long
b. The uncased portion of a borehole. Syn:bare; barefoot; naked.
Long

blankoff

To line a specific portion of a borehole with casing or pipe for the
purpose of supporting the sidewalls or to prevent ingress of unwanted
liquids or gas. Syn:case; case off CF:seal off

blank pipe

Unperforated pipe or casing set in a borehole. Long

blank reaming shell

A reaming shell in which no reaming diamonds or other cutting media are
inset on the outside surface. Long

Blanton cam

A device used for locking the cam on the camshaft in a stamp mill.
Fay

Blasjo cut

This is a cut with a single V where all the holes on one side are parallel
and meet the holes from the other side at an angle that may be as low as
30 degrees . Langefors

blast

a. The ignition of a heavy explosive charge. Syn:shot
b. A miner's term for compressed air underground. Nelson
c. Scot. A fall of water in the downcast shaft to produce or quicken
ventilation.
d. A suffix signifying a texture formed entirely by metamorphism.
AGI
e. The operation of increasing the diamond exposure on a bit face by
removing some of the matrix metal through the abrasive action of grains of
sand carried in a high-pressure stream of air. Also called sandblast.
Long
f. An increase in firing temperature of a kiln immediately before ending
the firing operation.
g. The period during which a blast furnace is in blast; i.e., in
operation.

blast coupling

The degree to which an explosive fills the borehole. Bulk-loaded
explosives are completely coupled. Untamped cartridges are decoupled.
Dick, 2

blast draft

The draft produced by a blower, as by blowing in air beneath a fire or
drawing out the gases from above it. A forced draft. Fay

blaster

a. A device for detonating an explosive charge. AGI
b. One who sets off blasts in a mine or quarry. A shot firer.
Syn:shooter
c. See:blasting unit

blast furnace

A shaft furnace in which solid fuel is burned with an airblast to smelt
ore in a continuous operation.

blast furnace dust

A dust recovered from blast furnace gases, some of which is valuable for
its potash content. Hess

blast furnace gas

A low-grade producer gas, made by the partial combustion of the coke used
in the furnace and modified by the partial reduction of iron ore. The gas
contains more carbon dioxide and less hydrogen than normal producer gas
made from coke and has a lower calorific value. Francis, 2

blast-furnace slag

The nonmetallic product, consisting essentially of silicates and
aluminosilicates of lime and of other bases, that is developed
simultaneously with iron in a blast furnace. Syn:slag

blast hearth

A hearth in connection with which a blast is used, as in reducing lead
ore. Fay

blasthole

A hole drilled in a material to be blasted, for the purpose of containing
an explosive charge.