The thin cavities formed along bedding planes due to differential lowering
of strata over mine workings; e.g., a shale with its greater bending
capacity will subside and separate from a higher bed of sandstone. Roof
supports are so set as to keep bed separation to a minimum. Nelson
A vein following the bedding in sedimentary rocks, or a mineralized
permeable stratigraphic zone below an impervious bed. CF:blanket vein;
manto; sheet ground.
Charcoal made from beechwood.
Scot. Strips of hardwood fastened to pump rods to save them from wear at
the collars. Fay
A quarry worker's term, used originally in Purbeck, southern England, for
thin, flat-lying veins or layers of fibrous calcite, anhydrite, gypsum,
halite, or silica, occurring along bedding planes of shale, giving a
resemblance to beef. It appears to be due to rapid crystallization in
lenticular cavities. See also:bacon
Coke manufactured in beehive, rectangular, or similar forms of ovens in a
horizontal bed, where heat for the coking process is secured by combustion
within the oven chamber. ASTM
A coke oven with a brick bottom, side walls, and a domed roof.
An intermittent kiln, circular in plan, with fireboxes arranged around the
circumference. Such kilns find use in the firing of blue engineering
bricks, pipes, some refractory bricks, etc. Syn:round kiln
Dodd
A machine for the multishot firing of series-connected detonators in
tunneling and quarrying. See also:exploder
A nodule of coprolitic ironstone, so named from the resemblance of the
enclosed coprolite to the body and limbs of a beetle. Syn:septarium
Fay
Flat rocks on which clothes were beetled (stamped or pounded).
A miner's term for that part of the orebody that still lies ahead.
See also:breast
A monoclinic mineral, (Na,Ca0.5 )0.3 Al2 (Si,Al) (sub
4) O10 (OH)2 .nH2 O ; smectite group; aluminum rich
and poor in magnesium and iron; a common constituent of soils and certain
clay deposits (e.g., metabentonite). CF:montmorillonite
An improved type of kep in which the kep shoes are withdrawn without
previously raising the cage and thus reducing the decking time. The
operation may be automatic, except for cage release, because the
arrangement allows the kep shoes to trip without the position of the hand
lever being altered. See also:kep
A pneumatic stowing machine that consists of a paddle wheel with six
compartments working inside an adjustable airtight casing. This wheel is
driven at a speed of 15 to 30 rpm by means of an air turbine through
gearing. Two sizes of Beien machines are used having capacities of 30 yd
3 and 60 yd3 (22.9 m3 and 45.9 m3 ) of
stowing material per hour, respectively. The dirt falls from the paddle
wheel into the airstream in the pipe underneath the paddle box and passes
along 6-in (15.2-cm) diameter pipes to the outlet, where a detachable
deflector guides the stream of dirt into the required place in the pack
hole. Mason
Flow layer resulting from incipient fusion during polishing of mineral
surface, and therefore not characteristic of true crystal structure.
Pryor, 1
A bowstring design of girder fabricated entirely from timber components.
Hammond
A rectangular variation of the beehive coke oven.
See also:Belgian oven
A temperature scale used in Belgium for measuring the environmental
comfort in mines. Roberts, 1
A rectangular oven with end doors and side flues for the manufacture of
coke. See also:Belgian coke oven