a. Said of any structure, area, or zone fitted with an arrangement that
maintains nearly normal atmospheric pressure. Nelson
b. Said of any structure or area in which the pressure within is held
higher than the outside pressure.
The application of load to a structure so as to deform it in such a manner
that the structure will withstand its working load more effectively or
with less deflection. Hammond
The Hoyer method of prestressing concrete beams, precast in a workshop
with the tensioned wires embedded in them and firmly anchored.
Hammond
A system that enables breakdowns to be anticipated and arrangements made
to perform the necessary overhauls and replacements in good time.
The dense woody lenses in lignite that are equivalent to the vitrain in
coal of higher rank. AGI
A triclinic mineral, Ca4 B10 O19 .7H2 O(?) ;
earthy to porcelainous white; conchoidal fracture. Syn:pandermite
a. A bar used in opening the taphole of a furnace. Fay
b. A rod used for removing obstructions from tuyeres and blowpipes.
Fay
A tetragonal mineral, (K,Ba)(Ti,Fe)8 O16 ; cryptomelane
group; red; easily mistaken for rutile in leucite rocks; occurs at
Kimberley, Western Australia.
See:iriginite
In assaying, the bullion bead resulting from cupellation of an auriferous
or argentiferous lead button. Pryor, 1
Tin extracted from slag. Also spelled prillon. Standard, 2; Fay
A fuse composed of an explosive core within a textile or plastic covering.
It detonates every explosive that is in direct contact with it.
Streefkerk
A detonating fuse having an explosive of pentaerythritetetranitrate
(PETN). Used in large-scale blasting work, esp. in quarries. Lewis
a. Characteristic of or existing in a rock at the time of its formation;
pertains to minerals, textures, etc.; original. Ant: secondary.
b. Said of a mineral deposit unaffected by supergene enrichment.
AGI
c. Said of a metal obtained from ore rather than from scrap.
Syn:virgin
An anomaly formed by primary dispersion.
A presumed original magma, from which all other rock types are obtained by
various processes of fractional crystallization.
A blast used to fragment and displace material from its original position
to facilitate subsequent handling and crushing. Atlas
The blasting of solid rock, ore, or coal; blasting in situ.
See also:secondary blasting
A machine that takes over the work of size reduction from blasting
operations; may be a gyratory or jaw breaker. Its capacity must be greater
than the overall crushing plant capacity. In mines, primary ore crushing
to about 7 in (18 cm) may be performed underground.
See also:reduction ratio; tertiary crushing. Nelson
A stage in bituminous coal crushing that occurs at the entrance to a plant
and consists of raw feed flowing into the primary breaker for reduction to
a maximum top size of 4 in, 5 in, 6 in, or 8 in (10.2 cm, 12.7 cm, 15.2
cm, or 20.3 cm) either for washing or for other preparation purposes.
Mitchell
a. A group or bank of flotation cells in which the raw feed is given a
preliminary treatment, either or both of the products being subsequently
retreated. BS, 5
b. A cell that generates or makes its own electrical energy from the
chemical action of its constituents; e.g., the voltaic cell, Deaniell
cell, LeClanche cell, and dry cell. Morris