A drive-type soil-sampling device that is essentially a headpiece,
threaded to fit a drill rod, to which is attached a removable length of
thin-wall brass or steel tubing. An example is the Shelby tube.
Long
A method of mining pillars in which no stump is left; the pockets driven
are open on the goaf side and the roof is supported on timbers.
Lewis
The first hole or holes fired in a round blasted off the solid to create
an additional free face in a coal mine. CFR, 4
A fault in which the two walls are separated. CF:closed fault
AGI
Fire occurring in a roadway or at the coal face in a mine. Such fires may
or may not be easily accessible. They may be in the roof of a roadway or
seam, or in the kerf of a machine-cut face. However, they are quite
distinct in their initiation from gob fires. An open fire may be ignited
by a blown-out shot, electrical failure, or from sparks produced by
friction. See also:spontaneous combustion
A fold in which the limbs diverge at a large angle. AGI
The arrangement of a blast furnace with a forehearth. Fay
Mineral aggregate containing very few small particles so that the void
spaces are relatively large. Shell
The form of regenerative furnace of the reverberatory type used in making
steel by the Martin, Siemens, and Siemens-Martin processes.
See also:furnace; open-hearth furnace.
A reverberatory melting furnace with a shallow hearth and a low roof. The
flame passes over the charge on the hearth, causing the charge to be
heated both by direct flame and by radiation from the roof and sidewalls
of the furnace. In the ferrous industry, the furnace is regenerative.
See also:open hearth
A process for manufacturing steel, either acid or basic, according to the
lining of the reverberatory furnace, in which selected pig iron and
malleable scrap iron are melted, with the addition of pure iron ore. The
latter, together with the air, contributes to the oxidation of the silicon
and carbon in the melted mass. The final deoxidation is sometimes produced
by the addition of a small quantity of aluminum or ferromanganese, which
at the same time desulfurizes and recarburizes the metal to the required
extent. See also:L
Fay
a. Coal or other mine workings at the surface or outcrop. Also called
opencast; opencut; open pit.
b. A borehole that is drilled without cores. Nelson
c. Uncased portion of a borehole. Pryor, 3
d. A borehole free of any obstructing object or material. Long
a. A widening out of a crevice, in consequence of a softening or
decomposition of the adjacent rock, so as to leave a vacant space of
considerable width. Fay
b. A short heading driven between two or more parallel headings or levels
for ventilation. Fay
c. Surface entrance to mine workings. Syn:mine opening
The formation of a longwall face by driving headings and cross headings
and connecting the faces to form a continuous line of coal face. It may be
viewed as the final stage in development, leading to full coal production.
In pillar-and-stall mining, opening out would imply the setting off of the
main headings and subsidiary drivages for the formation of coal pillars.
See also:branch headings; mechanized heading development.
Nelson
a. The parts of coal mines between the pillars, or the pillars and ribs.
Fay
b. A series of parallel chambers or openings, separated by pillars or
walls, in slate mining. The width of an opening varies from 35 to 50 ft
(11 to 15 m) depending on roof conditions. Nelson
In blasting into solid rock, the wedging shot, gouging shot, or burn cut.
Leading shot fired to open up the rock face by creating a cavity and
therefore easing the work done by later shots in a round. Pryor, 3
Quantity on hand at start of accounting period--ore, concentrates, stores,
etc. Pryor, 3
Lagging placed a few inches apart.
A naked light. Not a safety light. Fay
a. To turn stalls off stalls, or to drive branch roadways from
crossheadings. Nelson
b. Eng. To begin the longwall system from the shaft pillar, or the far end
of the royalty, or from any headings previously driven out for the purpose
of commencing such system. Fay
c. To start any new working, as a heading, entry, gangway, room, etc.,
from another working, as a slope, gangway, etc. Fay