In salt production, a laborer who adjusts the height of the gate in the
chute leading from the crusher by means of a lever, to regulate flow of
crushed rock salt into vibrating screens that separate salt into various
sizes prior to shipment or refining. DOT
See:marker block
Scot. An iron rod at the foot of pump rods to which the bucket is
attached. Fay
a. The underlying side of a fault, orebody, or mine working; esp. the wall
rock beneath an inclined vein or fault. Syn:heading wall; heading side;
lower plate; foot. CF:hanging wall
AGI
b. The wall or rock under a vein. It is called the floor in bedded
deposits.
c. Opposite wall from hanging wall.
d. S. Afr. The wall on the lower side of a reef, lode, or fault.
e. Can. The underside of a vein or lens in relation to the dip of an ore
deposit.
f. In metal mining, the part of the country rock that lies below the ore
deposit.
The lower wall of an inclined fault plane. Ballard
See:underlay shaft
In Pennsylvania, a miner's measurement of length, such as the distance a
working face is advanced. With the heel of one foot on a mark, a short
step is taken and the tip of the forward toe marks the foot-yard. The next
measurement is taken by placing the first foot against the toe of the
second and repeating the first step and so on. The foreperson checks
measurements with a rule. Hess
A percussive boring system comprising a closed-in derrick over the crown
pulley of which a steel rope is passed from its containing drum. The
boring tools are suspended from the end of the rope and are moved in the
hole as required by means of the drum. A walking beam, operated by a
driving mechanism, gives the boring tools a rapid vibrational motion.
Nelson
One of the original freezing methods of shaft sinking through heavily
watered sands. Although the principle is the same today, the process has
been improved in many respects. See also:freezing method
Nelson
See:foraminifer
Any protozoan belonging to the subclass Sarcodina, order Foraminifera,
characterized by the presence of a test (shell) of one to many chambers
composed of secreted calcite (rarely silica or aragonite) or of
agglutinated particles. Most foraminifers are marine but freshwater forms
are known. They are important microfossils in well logging. Range,
Cambrian to present. Syn:foram
Plural of foraminifer.
A mixture of annabergite and arsenolite.
Four lengths of drill rod or drill pipe connected to form a section, which
is handled and stacked in a drill tripod or derrick as a single unit on
borehole round trips. Also spelled fourble. CF:treble
That which tends to put a stationary body in motion or to change the
direction or speed of a moving body. AGI
A system in which the duct delivers the intake air to the face. The
forcing system may be used with flexible ducting and simplifies
arrangements for protecting the duct from blasting. The forcing system has
the added advantage that the fan motor always works in intake air, and no
special arrangements about fan drives are necessary.
See also:auxiliary ventilation
A stoping system in which the ore is broken down by large blasts into the
stopes, which are kept partly full of broken ore. The large blasts break
ore directly into the stopes and have the further effect of shattering
additional ore, part of which then caves.
A system of ventilation in which the fan forces air through the workings
under pressure. BS, 8
Stress fields can be represented by lines, each of which represents a
definite force, so that their distance apart is a measure of the intensity
of stress. The concept is similar to that of a magnetic field represented
by lines of force. Spalding
a. The clause in a metal supply contract which allows the seller not to
deliver or the buyer not to take delivery of the metal concentrate or
scrap under the contract because of events beyond the seller's control.
Wolff
b. An unexpected occurrence beyond the control of parties to a contract,
such as an earthquake preventing the timely delivery promised by a metal
supply contract, that typically relieves a party from contract
performance. The language of the contract, as well as applicable State or
Federal laws, determine the applicability of this legal mechanism in any
given situation. Also called an Act of God. Padan
The effective diameter of the piston or hammer, its weight, distance of
travel, and the air pressure during the forward movement. The energy of
the blow in foot-pounds is equal to: 1/2 mv2 = w X v2 /
64.4, where m = the mass; w = the weight in pounds; v = the velocity of
the hammer in feet per second. Lewis