The series of carefully woven, square-mesh wire screens most commonly used
in the United States in screening ores. Newton, 1
Eng. A horizontal roof timber in a coal mine; a cap or lid.
Standard, 2
A large clay plug filling an open space in the front jackets of a smelting
furnace, through which the taphole passes. Standard, 2
See:tyndallometer
The scattering or reflection of a strong beam of light by suspended
colloids; no such scattering or reflection comes from true solutions.
An instrument that measures the intensity of the light scattered at an
angle from the incident beam by a dust cloud. It correlates well with the
concentration determined by a thermal precipitator and surface area
calculated from such a count. It needs to be calibrated for each type of
dust against the thermal precipitator. Syn:tyndalloscope
See also:dust sampling
See:tyndallometer
a. See:rock type
b. A coal classification based on the constituent plant materials.
CF:rank; grade. AGI
c. Those differences in coals that are due to variations in the kind of
plant material of which the coal is composed, whereby such varieties as
common banded coal, cannel coal, algal coal, and splint coal are produced.
AGI
d. A kind, particularly in petrology (rock type); either general (for
example, basalt is a rock type) or particular (for example, a particular
basalt from a particular locality is a unique type specified by a
description). Challinor
A single-shot borehole-surveying instrument utilizing photographic paper
on which is recorded the compass bearing and inclination of the course of
a borehole. The type-D instrument, when mounted in a special thin-walled
protective container, is small enough to be used in an AX-size hole.
Long
A single-shot borehole-surveying instrument that records the compass
bearing and inclination of the course of a borehole through the action of
a strong beam of light directed through the plumb bob onto a
light-sensitive paper disk. It is similar to, but larger than, a type-D
drift indicator. Long
a. The concept type provides a means for classifying standard varieties of
coal microscopically on the basis of simple proportions of anthraxylon or
anthraxylon and opaque attritus, including their subdivision into banded
and non-banded coals. IHCP
b. A type of coal is a variety initially determined by the nature of the
ingredient matter, the conditions of deposition, and the extent of
operation of the first or biochemical process of coal making. IHCP
The originally described sequence of strata that constitute a
stratigraphic unit. It serves as an objective standard with which
spatially separated parts of the unit may be compared, and it is
preferably in an area where the unit shows maximum thickness and is
completely exposed (or at least shows top and bottom). AGI
A specimen or individual designated as type of a species or lesser group
and serving as the final criterion of the characteristics of that group.
Webster 3rd
A mechanical single-shot borehole-surveying instrument for use where
exceptionally high temperatures are encountered in a hole. It records the
compass bearing and inclination of a borehole by making a dot on a special
paper by means of a plumb bob, incorporating a depressible stylus.
Long
Rocks that have come from the depths of the Earth; i.e., plutonic and
eruptive rocks. Fay
A mineral that is typically developed in only a narrow range of
temperature and pressure. CF:index mineral
a. A variety of fergusonite found near Arendal, Norway. Fay
b. See:sipylite
Adjustable annular ring, made of plastic, used to control the aperture
area at the apex of a hydrocyclone. Pryor, 3
An orthorhombic mineral, Ca2 Cu9 (AsO4 )4 (OH)
10 .10H2 O ; forms green crystal aggregates having foliated
micaceous structure. Formerly called trichalcite.
An orthorhombic mineral, Ca(UO2 )2 (VO4 )2 .8H
2 O ; soft; waxy; yellow; fluoresces yellow-green; in secondary
encrustations in limestones, sandstones, or concentrated by organic
matter; associated with malachite, ferghanite, turanite, barite, calcite,
carnotite, and vanadium minerals; widely distributed in the Colorado
Plateau area; source of uranium and vanadium. Formerly called
calciocarnotite.
A popular type of rotary bit used in British mining practice. It has two
cutting legs, although some American and German bits employ three legs. A
core is formed between the legs, which is broken off as cutting proceeds;
some bits have a core-cutting device consisting of a tungsten carbide tip
in the center. Fraenkel