Uranium-Mining Practices and Costs at Ten Salt Wash Lease Operations of Union Carbide Nuclear Co. Page: 28
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inclines, was slushed between the collars of the inclines and the bins on ap-
proximately the same slope as the inclines. The inclines were sunk to the
bottom of the ore, and the haulageways (6 by 7 feet in section) were driven in
the ore zones.
Through 1957 the thickness of the ore at the Firebird and Ground Hog
mines averaged about 3 feet. The ore layers are typical of the Salt Wash,
rolling and undulating irregularly. The higher grade ore seams often are sep-
arated by barren or low-grade bands. The thinnest ore mined was 10 inches.
The thickest ore occurred where the rolls turned abruptly upward to make ore
bodies 6 to 7 feet high and 3 to 4 feet wide.
Drilling is done with airleg-mounted drills. When drifting in the massive
and harder barren sandstone, the partners prefer 7/8-inch hexagonal steel with
integral, 1-17/32-inch, tungsten carbide insert chisel bits. In the softer
ore they use the same size steel but increase their drilling rate by employing
one-use, 1-3/4-inch, four-wing Ingersoll-Rand Sandbits. They reported that
chisel-type bits bind when drilling in fractured ground, and the waterhole
tends to plug in the mudstone seams associated with the ore. The Sandbit has
deep-slotted, tapered flutes between its wings; its wings protrude sharply
above the body of the bit and the deep-set center waterhole. The deep-set
waterhole reduces bit plugging, and the ample clearance between the wings per-
mits easy passage of cuttings.
Fourteen holes, spaced about a four-hole burn cut, are drilled to break a
5-foot round in a 6- by 7-foot drift. The miners load seven sticks of 1-1/8-
by 8-inch, 30-percent semigelatin dynamite into the four cut holes; they load
six sticks into all reliever and trim holes and load the lifters full. The
miners are not particularly concerned with fly ore in the stopes, as scrapers
are used to slush the ore to the haulage drifts. Much of the ore has to be
mined selectively. When either the upper or lower half of a face is ore, they
normally break out the softer ore first. To recover a thin, high-grade seam
of ore which they cannot afford to break separately, the miners drill all
blastholes in waste so as to pull the ore to the cut in large slabs. These
slabs then can be sorted from the waste. When there are waste seams in an ore
face, the cut is placed in the ore with only enough holes in the waste to
break it in large slabs. Generally, when thin ore is being followed it is
kept high in the face if possible.
Every man in the mine is ore conscious. From the muck pile to the sur-
face, the ore and waste are watched carefully to prevent ore from being thrown
over the dump and waste getting into the bin. Often the low-grade ore is dif-
ficult to distinguish, and only in sunlight can the faint yellow ore streaks
The ore is moved underground from the stopes to the haulage drifts with
scrapers. When the ore is at or below track level, it is scraped over timber
ramps into the cars. From stopes above track level the ore is scraped directly
onto the track (fig. 12) and picked up with an overhead loader (fig. 13).
Where space is limited, hand mucking is often necessary. The ore is hand-
trammed to the bottom of the inclines in low, 18.5-cubic-foot mine cars over
12-pound rail laid to 18-inch gage.
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Dare, W. L. Uranium-Mining Practices and Costs at Ten Salt Wash Lease Operations of Union Carbide Nuclear Co., report, 1959; Washington D.C.. (digital.library.unt.edu/ark:/67531/metadc170712/m1/34/: accessed June 24, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.