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steel wire rope

See:wire rope

steenstrupine

A trigonal mineral, Na14 Ce6 Mn+2 Mn+3 Fe
2 (Zr,Th)(Si6 O18 )2 (PO4 ) (sub 7) .3H
2 O .

steep

See:brasque

steep gradient

In general, in coal mining, an inclination (of a roadway, working, or coal
seam) steeper than 1:4. Nelson

steeply inclined

Deposits and coal seams having a dip of from 40 degrees to 60 degrees .
Stoces

steering brake

A brake that slows or stops on one side of a tractor. Nichols, 1

steering clutch

A clutch that can disconnect power from one side of a tractor.
Nichols, 1

Stefan-Boltzmann Law

a. The energy radiated in unit time by a black body is given as E=K(T
4 -T04 ) , where T is the absolute temperature of
the body, T0 the absolute temperature of the surroundings, and K is
a constant. Osborne
b. The statement that the radiant flux of a black body is equal to the
absolute temperature to the fourth power times the Stefan-Boltzmann
constant of (5.6696+ or -0.001)X10-8 W (m)-2 (K) (super
-4) . AGI

steigerite

A monoclinic mineral, AlVO4 .3H2 O ; weakly radioactive;
forms coatings on highly weathered sandstones of the Colorado-Utah
carnotite region.

stein

Stonework used to secure the sides of a shaft. Gordon

steinmannite

A variety of galena with part of the lead replaced with antimony and
arsenic. Standard, 2

stele

In coal, primarily the vascular tissues of the axis of a vascular plant.
It consists of two parts: the xylem that carries water from the roots, and
the phloem that carries the food. Hess

stell

See:sprag

stellate

Said of an aggregate of crystals in a starlike arrangement; e.g.,
wavellite.

stell prop

A steel or timber prop fixed firmly between the roof and the floor at the
end of a longwall face and from which a coal cutter is hauled by rope when
cutting. A stell prop may also be used as part of a belt-tensioning
arrangement or a return sheave. Syn:anchor prop
See also:conveyor creep

stem

a. To insert and pack stemming in a shothole. See also:tamp
BS, 12
b. The assemblage of drill rods in a borehole connecting a drill bit and
core barrel to the drill machine. Long
c. The heavy iron rod acting as the connecting link between the bit and
the balance of the string of tools on a churn rod in a borehole connecting
a drill bit drill. Long
d. Frequently used as a syn. for ram or tamp. See:stemming

stem bag

Fire-resisting paper bag, about 8 in (20.3 cm) long, filled with dry sand
for stemming shotholes in coal or hard headings.
See:water-ampul stemming

stemmer

A wooden rod used by shot firers for inserting the explosive cartridges
and stemming material in shotholes. The stemmer must be long enough to
reach the back of the shothole, and has a diameter 1/8 in (3.2 mm) larger
than the cartridges. Metal is not permitted in any part of a stemmer used
in British coal mines. Also called tamping rod or stick; beater.
See also:tamping; scraper; break detector. Nelson

stemming

a. The material (limestone chippings or sand and clay) used to fill a
shothole, after the explosive charge has been inserted, to prevent the
explosion from blowing out along the hole. In tunnels and hard headings,
the stemming may be blown in by a hurricane air stemmer. Nelson
b. The act of pushing and tamping the material in the hole.
See also:water-ampul stemming; tamp. Nelson
c. Inert material packed between the explosive charge and the outer end of
the shothole, or between adjacent charges in deck charging. BS, 12
d. See:tamping; stem.

stemming rod

A nonmetallic rod used to push explosive cartridges into position in a
shothole and to ram tight the stemming. Syn:stemming stick
See also:tamping stick; tamping rod. BS, 12

stemming stick

See:stemming rod