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spoils

a. See:cuttings
b. The debris or waste material from a mine. Long

sponge

a. A form of metal characterized by a porous condition, which is the
result of the decomposition or reduction of a compound without fusion. The
term is applied to forms of iron, the platinum-group metals, titanium, and
zirconium. Metal has appearance of a sponge due to high porosity.
ASM, 1
b. Hafnium produced by the Kroll process. Thomas

sponge iron powder

Ground and sized sponge iron, which may have been purified or annealed or
both. ASTM

sponge metal

A form of metal characterized by a porous condition, which is the result
of the decomposition or reduction of a compound without fusion. Metal has
the appearance of a sponge due to high porosity. ASM, 1

spongy

Said of a vesicular rock structure with thin partitions between the
vesicles, thus resembling a sponge.

spongy iron

See:reduced iron

spontaneous

Used to describe the driving potential that causes electric currents to
circulate in boreholes. These currents are not in any way deliberately
induced by the well-logging equipment. Also called self-potential; SP
curve. See also:spontaneous potential curve

spontaneous combustion

a. The heating and slow combustion of coal and coaly material initiated by
the absorption of oxygen. The two main factors involved are (1) a coal of
a suitable chemical and physical nature; and (2) sufficient broken coal
and air leaking through it to supply the oxygen needed. The heat generated
is retained with consequent rise in temperature. See also:gob fire;
hydrogen sulfide; open fire; weathering of coal. Nelson
b. The outbreak of fire in combustible material that occurs without the
direct application of a flame or a spark. It is usually caused by slow
oxidation processes (such as atmospheric oxidation or bacterial
fermentation) under conditions that do not permit the dissipation of heat.
c. Ignition that can occur when certain materials such as tung oil are
stored in bulk, resulting from the generation of heat, which cannot be
readily dissipated; often heat is generated by microbial action. Also
known as spontaneous ignition. McGraw-Hill, 1

spontaneous polarization

a. Electrochemical reactions of certain orebodies causing spontaneous
electrical potentials. Schieferdecker
b. See:self-potential method; spontaneous potential method.

spontaneous potential curve

The electric log curve that records changes in natural potential along an
uncased borehole. Small voltages are developed between mud filtrate and
formation water of an invaded bed, and also across the shale-to-mud
interface. These electrochemical components are augmented by an
electrokinetic potential (streaming potential) developed when mud filtrate
moves toward a formation region of lower fluid pressure through the mud
cake. Where formation waters are less resistive (more saline) than
drilling-mud filtrate, the spontaneous-potential curve deflects to the
left from the shale baseline. First used about 1932, the curve was added
to the resistivity log to make up the basic electric log of well-logging
practive. Syn:SP curve; self-potential curve. AGI

spontaneous-potential method

See:self-potential method

spontaneous potential method

An electrical method in which a potential field caused by spontaneous
electrochemical phenomena is measured. Syn:self-potential method;
spontaneous polarization. AGI

spool

a. Cast iron distance piece placed between timbers. Hammond
b. To wind rope or cable on a hoist drum. Long
c. The drum of a hoist. Long
d. The movable part of a slide-type hydraulic valve. Nichols, 1
e. To wind in a winch cable. Nichols, 1

spool-type roller conveyor

A type of roller conveyor in which the rolls are of conical or tapered
shape with a diameter at the ends of roll larger than at the center.

spoon

A tool for cleaning dust or sludge from quarry blasting holes.
Syn:scraper

spooner

In bituminous coal mining, a laborer who scoops drillings out of boreholes
in which explosives are to be charged for blasting down coal, using a
slender iron rod with a cup-shaped projection bent at right angles to the
handle. DOT

spooning

Many mineral raw materials, such as petroleum, cementation water (water
containing dissolved copper or iron sulfates or other metal compounds), or brine are extracted by pumping through boreholes. In spooning, a long
spoon (a hollow cylinder with a bottom equipped with a clap valve, or ball
valve, and open above) is attached to a cable that is let down into the
boreholes where the cylinder fills with the liquid; this is emptied out
after the cylinder is raised. Stoces

spoon proof

Test-ladle specimen taken during various stages of melting and fining.
ASTM

spoon sampler

A rotating soil sampler, fitted with an auger-type cutting shoe.
Long

spore

Part of the reproduction organs of many coal measures' plants. There are
two kinds, namely, megaspores (female) and microspores (male). They are
found in most coal seams, particularly the dull layers. Megaspores vary
from 1 to 5 mm in size, and microspores (or pollen grains) from about 0.01
to 0.1 mm. Nelson

spore coal

a. Coal in which the attritus contains a large amount of spore matter
along with transparent attritus. See also:cannel coal
b. Coal formed out of the spores of lycopods.