In process control, the element that directly changes the value of the
manipulated variable. Fuerstenau
The detailed investigation of a coal or mineral area on which a
preliminary report was favorable. The final exploration of an area may
involve a costly boring program, surveys, and sampling.
See also:preliminary exploration
a. Composed of or constituting relatively small particles; e.g., fine
sandy loam. Ant. coarse. AGI
b. Sometimes used to designate high-quality drill diamonds. Long
c. A measure of the amount of gold in electrum.
The portion of an aggregate consisting of particles with diameters smaller
than approx. 1/4 in (4.8 mm). CF:aggregate; coarse aggregate.
AGI
a. Almost pure gold. The value of bullion gold depends on its percentage
of fineness. See also:fineness; float gold.
b. In placer mining, gold in exceedingly small particles.
Syn:greasy gold
a. Said of a crystalline rock, and of its texture, in which the individual
minerals are relatively small; specif. said of an igneous rock whose
particles have an average diameter less than 1 mm. Syn:aphanitic
AGI
b. Said of a sediment or sedimentary rock, and of its texture, in which
the individual constituents are too small to distinguish with the unaided
eye; specif. said of a sediment or rock whose particles have an average
diameter less than 1/16 mm (62 mu m, or silt size and smaller). The term
is used in a relative sense, and various size limits have been used.
CF:coarse-grained; medium-grained. AGI
c. Said of a soil in which silt and/or clay predominate. AGI
Rocks in which the crystals are very fine-grained, or else the whole or
part is glass. These are the volcanic rocks. Mason
A machine for the final stage of size reduction; i.e., to -100 mesh.
See:fine grinding; pulverizer.
Fine grinding is usually performed in a mill rotating on a horizontal axis
and containing balls, rods, or pebbles (grinding media), which serve to
grind the ore in the mill. The different mills used in fine grinding are
known as ball mill, pebble mill, Hardinge mill, tube mill, autogenous,
etc. Newton, 1
See:toolstone
The higher grades of copper regulus or matte obtained in the English
process of copper smelting. Included are the following four varieties,
which are distinguished by appearance and copper content: (1) blue,
containing about 60% copper; (2) sparkle, about 74% copper; (3) white,
about 77% copper; and (4) pimple, about 79% copper. Fay
a. The proportion of pure silver or gold in jewelry, bullion, or coins;
often expressed in parts per thousand; American silver coin is nine-tenths
or 0.900 fine; English gold coin is eleven-twelfths or 0.9166 fine.
Webster 3rd
b. A measure of specific surface area or particle-size distribution.
Taylor
c. The state of subdivision of a substance. CTD
A measure of the average particle size of clay and ceramic material,
computed by summing the products of the reciprocal of the size-grade
midpoints and the weight percentage of material in each class (expressed
as a decimal part of the total frequency). The measure is based on the
assumption that the surface areas of two powders are inversely
proportional to their average particle sizes. Syn:surface factor
AGI
a. A means of evaluating sand and gravel deposits, consisting of passing
samples through standardized sets of sieves, accumulating percentages
retained, dividing by 100, and comparing the resultant fineness-modulus
number to various specification requirements. AGI
b. An empirical factor obtained by adding the total percentages of a
sample of the aggregate retained on each of a specified series of sieves,
and dividing the sum by 100. AIME, 1
c. One-hundredth of the sum of the cumulative values for the amount of
material retained on the series of Tyler or U.S. sieves including half
sizes up to 100 mesh. Dodd
a. Finely crushed or powdered material, e.g., of coal, crushed rock, or
ore, as contrasted with the coarser fragments; esp. material smaller than
the minimum specified size or grade, such as coal with a maximum particle
size less than 3.2 mm, or ores too pulverulent to be smelted in the
ordinary way; or material passing through a given screen or sieve.
AGI
b. An engineering term for the clay- and silt-sized soil particles
(diameters less than 0.074 mm) passing U.S. standard sieve No. 200.
AGI
c. See also:anthracite fines
a. A geologic term for a sand particle having a diameter in the range of
0.125 to 0.25 mm (125 to 250 mu m, or 3 to 2 phi units). Also, a loose
aggregate of sand consisting of fine sand particles. See also:sand
AGI
b. An engineering term for a sand particle having a diameter in the range
of 0.074 mm (retained on U.S. standard sieve No. 200) to 0.42 mm (passing
U.S. standard sieve No. 40). AGI
c. A soil term used in the United States for a sand particle having a
diameter in the range of 0.10 to 0.25 mm. AGI
A geologic term for a silt particle having a diameter in the range of
1/128 to 1/64 mm (8 to 16 mu m, or 7 to 6 phi units). In Great Britain,
the range 1/100 to 1/20 mm has been used. Also, a loose aggregate of silt
consisting of fine silt particles. AGI
Pure silver, 1,000 parts fine or 100% silver.
a. One of the cutting edges on a finger bit. See also:finger bit
Long
b. A pair or set of bracketlike projections placed at a strategic point in
a drill tripod or derrick, generally at a level with one of the work
platforms, to keep a number of lengths of drill rods or casing in place
when they are standing in the tripod or derrick. Also one of the flexible
prong parts of a basket lifter. Long
c. A minor structure radiating from a major structure. AGI
Pivoted length of wood used to support a unit in a stamp battery.
See also:cam stick
A steel rock-cutting bit having fingerlike, fixed or replaceable,
steel-cutting points affixed. Long