a. A shaft sunk in the footwall and following the dip of a vein. Also
called underlier. Fay
b. Shaft that slopes at the dip angle of a lode, but is carried below the
ore. Also called a footwall shaft. See also:incline shaft
Pryor, 3
A development level or drift, driven from the surface, in ironstone
mining. Nelson
a. The angle at which stulls or posts are set between walls. The setting
angle is slightly steeper than the perpendicular to the vein, and the post
thus tightens with the downward settlement of the hanging wall.
Nelson
b. To lie or be situated under, to occupy a lower position than, or to
pass beneath. The term is usually applied to certain rocks over which
younger rocks (usually sedimentary or volcanic) are spread out. Ant:
overlie. Syn:underlay
Insufficient charging of a ball mill for proper grinding of enamel slip.
ACSB, 2
Lying under or beneath; fundamental. See also:seat earth
Webster 3rd
The rocks situated under a deposit or other strata. Stoces
In Great Britain, the underground mining engineer and senior executive
official. Everything that has to do with the underground must be subject
to his or her control, esp. regarding safety and health of personnel. Also
called underlooker. Syn:under
To excavate the earth beneath, esp. for the purpose of causing to fall;
form a mine under. See also:undercut; underhole. Webster 3rd
a. Building up the wall of a mine shaft to join that above it. Fay
b. The act of supporting a superior part of a wall, etc., by introducing a
support beneath it. Fay
To reduce to metal the cuprous oxide from blister copper produced in a
converter, green poles are pushed into the molten material to bring the
percentage of dissolved oxygen below 0.5. If this reaction (which results
in flat-topped ingots having a smooth fracture) is incomplete, the ingot
fractures too readily and has a darker color. This shows it to have been
insufficiently reduced, or underpoled. See also:tough pitch
Pryor, 3
To enlarge or ream a borehole below the casing. See also:underreaming
Long
A tool or device having cutters that can be expanded or contracted by
mechanical or hydraulic means and used to enlarge or ream a borehole below
the casing or drivepipe. Also called expansion bit; expansion reamer.
See also:hydraulic underreamer; underreamer bit. Long
The assembled device consisting of the lugs or jaws attached to an
expanding mechanism used to enlarge or ream a borehole below a string of
casing. See also:underreamer
See:underreamer lug
A diamond set or other type of expansible or contractable jaw on an
underreamer bit. Syn:underreamer cutter
Long
a. The widening out of the foot of a bored hole or of certain types of
foundation piers to increase the load-bearing area. Hammond
b. See also:underream
An expanding bit used to enlarge the diameter of the hole below the casing
to allow the casing to be lowered farther down the borehole. BS, 9
An endless rope haulage in which the ropes run under the cars. The cars
are attached singly or in short sets by clips.
See also:overrope haulage
a. Said of an igneous rock consisting of unsaturated minerals; e.g.,
feldspathoids and olivine. AGI
b. Said of a rock whose norm contains feldspathoids and olivine, or
olivine and hypersthene. CF:unsaturated; saturated; saturated rock.
AGI
Water that is fed into the cells of a washbox below the level of the
screen plate. BS, 5
The driving of exploring headings seaward from landside mine workings
combined with up-and-down boring to establish higher or lower seams. Also,
a technique developed by the National Coal Board, Great Britain, for
exploration drilling from a tower that can be floated out to sea and
grounded on the seabed. Nelson