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check viewer

In bituminous coal mining, one who inspects and checks portions of a mine
that have been leased to workers to see that the terms of lease, such as
mining within specified limits, safety precautions, and production rate,
are duly observed. DOT

checkweigher

In mining, one who checks, in the interest of miners, the weighing of coal
in mine cars or other containers by the company weighmaster. The person
estimates the amount of slate, dirt, rock, and other foreign matter in the
coal and sees that only authorized deductions are made. Also called
check-docking boss; check measurer; checkweighman; justiceman.
DOT; Fay

checkweighman

See:checkweigher

cheeking

The removal of the side or sides of a roadway to increase its width.
TIME

cheeks

a. The sides or walls of a vein. Fay
b. Extensions of the sides of the eye of a hammer or pick. Fay
c. The refractory sidewalls of the ports of a fuel-fired furnace.
Dodd

chelate compound

The compound formed by the combination of a chelating agent and a metal
ion. ASM, 1

chelating agent

A substance that contains two or more electron donor groups and will
combine with a metal ion so that one or more rings are formed.
ASM, 1

chelation

The reaction between a metallic ion and a complexing agent, generally
organic, with the formation of a ring structure and the effective removal
of the metallic ion from the system. It is significant in chemical
weathering. AGI

cheleutite

a. A ferruginous, nickeliferous, and slightly cupriferous smaltite.
See also:smaltite
b. A copper-bearing variety of smaltite.

Chelsea color filter

An effective dichromatic color filter transmitting light of only two
wavelength regions--one in the deep red, the other in the yellow green.
Useful for discriminating between emerald and its imitations and for
detecting synthetic spinels and pastes colored blue with cobalt.
Anderson

chemawinite

A pale-yellow to dark-brown variety of retinite (amber) in decayed wood at
Cedar Lake, MB, Canada. Syn:cedarite

chemechol

A method of breaking down coal similar to Hydrox and applied on the same
lines as air shooting. Nelson

chemical adsorption

Surface adherence, accompanied by the formation of primary bonds.
Van Vlack

chemical affinity

a. The force that binds atoms together in molecules. CTD
b. The tendency of one substance to form a chemical compound with another.
Hess

chemical analysis

A method of determining the composition of a material employing chemical
techniques by which the various elements are quantitatively separated.

chemical brick

See:chemical stoneware

chemical-clay grout

A typical grout of this class used in Great Britain is bentonite-sodium
silicate, in which the silicate is used to render irreversible the
thixotropic nature of the bentonite suspension. The gel is stronger than
pure bentonite and is permanent, in that local vibration cannot cause it
to liquefy again. Setting time can be controlled by adjustment of the
chemical content. Nelson

chemical combination

Change in which permanent alteration of properties occurs, accompanied by
intake or release of energy. Reaction is governed by laws of mass
conservation, definite and multiple proportions, equivalence, and
volumetric reaction. Pryor, 3

chemical composition

The weight percent of the elements (generally expressed as certain oxide
molecules) in a rock. AGI

chemical constitution of coal

The elements or component parts of coal. These are determined by chemical
analyses that may be performed in different ways. An ultimate analysis
provides exact information as to the percentages of the various elements
(such as carbon, oxygen, and hydrogen) present in the coal. Another method
is by proximate analysis, which determines the relative percentages of
carbon, moisture, volatile matter (such as gas and tar), sulfur, and ash.
Nelson

chemical denudation

The processes in which the salts or the soluble minerals in the Earth are
dissolved by water and carried to the sea. Bennett