The product resulting from the artificial crushing of gravel with
substantially all fragments having at least one face resulting from
fracture.
a. The product resulting from the artificial crushing of rocks, boulders,
or large cobblestones, substantially all faces of which have resulted from
the crushing operation. ASTM
b. Term applied to irregular fragments of rock crushed or ground to
smaller sizes after quarrying. Syn:broken stone
A mineralized zone or belt of crushed material. The crushing was caused by
folding, faulting, or shearing. Fay
A machine for crushing rock or other materials. Among the various types of
crushers are the ball-mill, gyratory-crusher, Hadsel mill, hammer mill,
jaw crusher, rod mill, rolls, stamp mill, and tube mill. Fay; Hess
In quarry industry, one who feeds broken rock into crusher after it is
dumped from trucks or cars, by pushing it down a chute with a shovel or
bar, or by pushing it directly into crusher from a platform. Also called
crusher loader; crusher laborer; stone breaker; trap person. DOT
a. In the mineral and nonmineral industry, including coal, quarry
products, mineral and nonmineral ores, a person who operates a machine
that crushes rock or other material and regulates the flow of such
material into and from the crusher to the next point of processing or use.
See also:crusher; crusher feeder; crushing.
b. In quarrying, a person who operates crusher through which broken quarry
rock is run to break it into crushed stone for construction work.
DOT
a. Term used in quarrying to describe the weathered overlying rock that
occurs at most quarry operations and which is sold for use as road base.
b. The total unscreened product of a stone crusher. Shell
Steel or chilled iron roller with parallel horizontal axis and peripheries
at a fixed distance apart so that rocks, coal, or other substances of
greater thickness cannot pass between without crushing. Rolls may be
toothed or ribbed, but for rock, including ores, the surfaces are usually
smooth. Hess
Rock that has been broken in a mechanical crusher and has not been
subjected to any subsequent screening process. Taylor
The distance between roll faces or plates in a crusher. In the case of jaw
and roll crushers, the setting controls the maximum size, and to some
extent the grading of the product produced. The best setting is usually
that which produces 10% to 15% of oversize pieces, which are fed back for
recrushing. Gyratory breakers do not permit any marked variation in the
setting or in the size of the product. Nelson
A machine that crushes ripping stone in headings and projects it through a
pipe into gate side packs. It may also be used for filling old roadways or
roof cavities. See also:pneumatic stowing
A gate in a development face designed to be abandoned with a view to
localizing the crush effect consequent on the winning of the coal
immediately above or immediately below the development face. TIME
Size reduction into relatively coarse particles by stamps, crushers, or
rolls. See also:comminution
Diamond material with radial or confused crystal structure lacking
distinct cleavage forms. Color is faintly milky to grayish or dark and is
suitable only for crushing into grit powder or dust. The Bakwanga Mine,
Republic of the Congo, is the principal source of this material. Diamond
fragments from cutting establishments or recovered from waste are
frequently classed as crushing bort. Chandler
See:bort
The sequence of operations in crushing a material, including, e.g., the
screening of the primary product and the recirculation of the screen
overflow. BS, 5
A machine constructed to pulverize or crush stone and other hard and
brittle materials; a stone crusher. Fay
See:stamp mill; crusher.
A machine consisting of two heavy rolls between which ore, coal, or other
mineral is crushed. Sometimes the rolls are toothed or ribbed, but for ore
their surface is generally smooth. See also:roll
a. The resistance that a rock offers to vertical pressure placed upon it.
It is measured by applying graduated pressure to a cube, 1 in (2.54 cm)
square, of the rock tested. A crushing strength of 4,000 lb means that a
cubic inch of the rock withstands pressure to 4,000 lb (111 kg/cm (super
3) ) before crushing. The crushing strength is greater with shorter prisms
and less with longer prisms. Fay
b. The pressure or load at which a material fails in compression; used for
comparing the strength of walling and lining materials, such as concrete,
masonry, stone, packs, etc. Nelson
c. The maximum load per unit area, applied at a specified rate, that a
material will withstand before it fails. Typical ranges of value for some
ceramic materials are fireclay and silica refractories, 2,000 to 5,000 psi
(13.8 to 34.4 MPa); common building bricks, 2,000 to 6,000 psi (13.8 to
41.4 MPa); engineering bricks, class A, above 10,000 psi (69.0 MPa);
sintered alumina, above 50,000 psi (344 MPa). Dodd
a. A test of the suitability of stone to be used for roads or building
purposes; a cylindrical specimen of the stone, of diameter 1 in (2.54 cm)
and 1 in long, is subjected to axial compression in a testing machine.
Syn:unconfined compression test
b. A radial compressive test applied to tubing, sintered-metal bearings,
or other similar products for determining radial crushing strength
(maximum load in compression). ASM, 1
c. An axial compressive test for determining quality of tubing, such as
soundness of weld in welded tubing. ASM, 1