Of metals: the elastic limit, elongation, fatigue range, hardness, maximum
stress, reduction in area, shock resistance, and yield point.
Pryor, 3
A wrought-iron (rocking) furnace in which puddling is done by mechanical
motion instead of by hand. Mersereau, 2
A rabble worked by machinery. See also:rabble
A machine embodying a weight that is lifted and dropped upon the material
being rammed. See also:power rammer
Mechanical sampling systematically removes a portion of the stream of
material for a sample. Mechanical sampling is widely used in cone
preparation plants and concentrators where large quantities of materials
are to be sampled, while hand sampling is used for smaller amounts.
CF:hand sampling
Sediment that has been brought to its places of deposition as separate
particles by mechanical means. Water, wind, and ice are the agents
commonly involved; the resulting rocks are conglomerate, sandstone,
siltstone, shale, and certain limestones. Stokes
Bits produced by the various means in which diamonds are set in a bit mold
into which a cast or powder metal is placed, embedding the diamonds and
forming the bit crown, as opposed to handsetting. Also, the act or process
of producing diamond bits in such a manner. Also called cast set; machine
set; sinter set. CF:handset
A diamond bit produced by mechanical methods as opposed to handsetting
methods. See also:mechanical set
A loader limited to level or only slightly graded drivages. The machine
operates a shovel in front of it and pushes itself forward; when full, the
shovel is swung over the machine and delivers into a mine car or tub
behind. It will shunt, pull, and push its own cars, delivering them into a
shunt or passby when full. See also:shovel loader
Mixing two or more poorly graded soils to obtain a well-graded one.
Nelson
The process of weathering by which frost action, salt-crystal growth,
absorption of water, and other physical processes break down a rock to
fragments, involving no chemical change. CF:chemical weathering
Syn:disintegration
Subjecting metal to pressure exerted by rolls, presses, or hammers, to
change its form or affect the structure, and therefore the physical
properties. Rolfe
A steel prop in which yield is controlled by friction between two sliding
surfaces or telescopic tubes. Although crude when compared with the
hydraulic prop, the friction yield prop is very robust, is cheap, and
requires little maintenance. Nelson
The branch of physics that treats of the phenomena caused by the action of
forces on material bodies. It is subdivided into statics, dynamics, or
kinetics; or into the mechanics of rigid bodies and hydromechanics
(including hydrostatics and hydrodynamics). Standard, 2
Essentially, the introduction of power machines to replace manual labor.
In coal mining, it may denote the introduction of conventional machine
mining to replace hand mining, or continuous mining to replace
conventional machine mining. Nelson
Usually a qualified mining engineer with first-hand experience and
knowledge of the various mining machines and the physical conditions most
suitable for them. In general, the National Coal Board, Great Britain,
appoints a mechanization engineer for each group of collieries.
Nelson
A plan or project to convert a handmining or a conventional machine mining
face to mechanized mining; i.e., the use of machines that either load
prepared coal or cut and load coal simultaneously (cutter loaders). The
scheme may also include the introduction of locomotives, skip winding,
etc. Nelson
Term descriptive of a mine that has a high percentage of machinery for all
steps of mining and handling mineral product, from the face to the mine
working place, and on to the tipple or treatment plant. BCI
mechanized heading development
A pillar method of working suitable for seams 4 ft (1.2 m) and over in
thickness. Three or more narrow headings are driven rapidly with machines
at about 30-yd (10-m) centers with crosscuts for ventilation. The headings
are 10 ft (3 m) or more wide and 5 to 6 ft (approx. 2 m) high or seam
thickness. Upon reaching the boundary, the pillars formed by the headings
are extracted, again with machines, on the retreat. This method is favored
in the United States and the heading work is quite as productive, if not
more so, than pillar working. See also:entry; longwall retreating.
Nelson
The coal produced by all coal face machinery that either loads prepared
coal or cuts and loads coal simultaneously. Also includes all coal
obtained by hand filling on faces where an armored flexible conveyor is
used on a prop-free front. Nelson