a. The raw mined material as it is delivered by the mine cars, skips, or
conveyors and prior to treatment of any sort. See also:pithead output
Nelson
b. Average grade of ore produced from a mine. New South Wales
c. Said of ore in its natural, unprocessed state; pertaining to ore just
as it is mined. AGI
a. The unintentional escape of molten metal from a mold, crucible, or
furnace. ASM, 1
b. In mineral processing, the dumping of pulp before the contained solids
pack down and choke a stalled mechanism in the event of a breakdown or a
power failure. Pryor, 3
A forge in which cast iron is refined. Fay
Drill cuttings that are not collected or saved as a sludge sample and are
allowed to collect in the sump; also, the return drill-circulation fluid
not returned to a sump for recirculation. Long
A jig used chiefly on tin dredges to treat the undersize from the main
revolving screen. It differs from the Harz jig in that there is no
longitudinal division and the screening compartment extends over the whole
surface of the jig; the plungers are located in the hutch below the screen
are set in a vertical plane and reciprocate horizontally. Harrison
Deformation characterized by loss of cohesion. Frequently flow grades into
rupture, with a progressive loss of cohesion, until complete separation
occurs. See also:fracture
See:Mohr envelope
The term is used with reference to brittle materials; i.e., materials in
which failure occurs through tensile rupture rather than through excessive
deformation. For a member of given form, size, and material, loaded and
supported in a given manner, the rupture factor is the ratio of the
fictitious maximum tensile stress at failure, as calculated by the
appropriate formula for elastic stress, to the ultimate tensile strength
of the material as determined by a conventional tension test.
Roark
See:Mohr envelope
The differential stress that a material sustains at the instant of
breaking, or rupture. The term is normally applied when deformation occurs
at atmospheric confining pressure and room temperature. AGI
The region immediately adjacent to the boundary of an explosion crater
characterized by excessive in-place crushing and fracturing where the
stresses produced by the explosion exceeded the ultimate strength of the
medium. CF:plastic zone
a. A stampede of prospectors and miners into a new discovery area.
b. A place where gold is found in abundance. Standard, 2
See:rusty gold
Corn. A tetragonal mineral, Bi2 WO6 ; a yellow alteration
product with native bismuth and wolframite.
A metallurgical process similar to the Patera process, except that cuprous
sodium hyposulfite is used in addition to the sodium hyposulfite.
Liddell
A high-grade, smooth, glossy sheet iron, not liable to rust; once made by
a process that was long a secret with Russian manufacturers. The sheets
were subjected to severe hammering in piles with powdered charcoal between
them. Standard, 2
A colorless variety of gypsum.
a. A corrosion product consisting of hydrated oxides of iron. Applied only
to ferrous alloys. ASM, 1
b. A mixture of iron filings, ammonium chloride, and sometimes sulfur,
moistened and placed between iron surfaces, where it hardens by oxidation,
and forms a solid joint called a rust joint. Standard, 2
c. An English term for a black shale discolored by ocher. AGI
In anthracite and bituminous coal mining, a general term applied to any
worker who looks after the haulage system, performing the necessary work
by which mine cars are raised and lowered to and from the mine surface.
May be designated according to job, as clipper; rollerman. DOT
A process for the manufacture of stainless steels in an electric furnace
that uses a chrome ore as a source of chromium with or without the
addition of silicoferrochromium, conjointly with stainless steel scrap.
The hearth of the furnace is lined with chromite bricks. Osborne
Cal. Free gold, that does not readily amalgamate, the particles being
covered with a siliceous film, thin coating of oxide of iron or manganese,
etc. Syn:rush gold