A mine working or excavation open to the surface. See:strip mine
a. A form of operation designed to extract minerals that lie near the
surface. Waste, or overburden, is first removed, and the mineral is broken
and loaded, as in a stone quarry. Important chiefly in the mining of ores
of iron and copper. Barger
b. The mining of metalliferous ores by surface-mining methods is commonly
designated as openpit mining as distinguished from the strip mining of
coal and the quarrying of other nonmetallic materials such as limestone,
building stone, etc. See also:strip mining
A quarry in which the opening is the full size of the excavation. One open
to daylight. Fay
Fireclay pot for melting glass--open at the top. Mersereau, 2
Any stratum sufficiently open or porous to contain a significant amount of
water or to convey it along its bed. AGI
Large, open cracks or crevices and small and large caverns. Long
Casting made in a mold simply excavated in sand, without a flask.
Fay
Scot. An unfilled space between pack walls. See also:cundy
A shop, or mine, where the union price is paid, but where the workers are
not all union members. CF:union shop
A split in which no regulator is installed. Syn:free split
Higham
a. An unfilled cavity. Nelson
b. Underground working place either unsupported, or supported by timbers
or pillars of rock. Pryor, 3
a. Stoping in which no regular artificial method of support is employed,
although occasional props or cribs may be used to hold local patches of
insecure ground. The walls and roof are self-supporting, and open stopes
can be used only where the ore and wall rocks are firm. Jackson, 2
b. See:overhand stoping
A method of treating mine timber to prevent decay in which the timber is
immersed in a tank of hot preservative and then in a tank of cold
preservative. The preservatives used are creosote, zinc chloride, sodium
fluoride, and other chemicals. See also:timber preservation;
Bethell's process. Lewis
The usual method of setting timber or steel supports in mines--they are
spaced from 2 to 5 ft (0.6 to 1.5 m) apart, with laggings and struts to
secure the ground between each set. The method is used in ground that does
not crumble or flow. See also:close timbering
The main use of this type of bucket elevator has been in handling the
product of the larger crushers. Steel buckets of large capacity, which may
be as long as 7 ft (2.1 m), are attached rigidly to a heavy flat bar
chain, each strand made of two bars with a pitch of 2 and with self-oiling
flanged rollers at each intersection. The elevator rises at an angle of
about 60 degrees , and the rollers run on ways made of light T-rails. The
buckets have overlapping edges, so that there is no spill between them.
Pit and Quarry
A length of tubbing having no wedging crib on the top of it. Fay
A surveying traverse that starts from a station of known or adopted
position but does not terminate upon such a station and therefore does not
completely enclose a polygon. CF:closed traverse
Surface working, e.g., a quarry or opencast mine. Among the minerals often
exploited by open workings are coal, brown coal, gems; the ores of copper,
gold, iron, lead, and tin; and all kinds of stone. Also called open work.
Nelson
The mechanism used with the automatic duckbill through which the extension
and retraction of the shovel trough are controlled. Jones, 1
The sum of the costs of mining, beneficiation, and administration gives
the operating cost of a mine. Nelson
See:hoistman