The Mining Process
Site
Evaluation and Preparation
Site evaluation and preparation requires planning to meet
permitting requirements. Guidelines for clearing tress
and vegetation; stripping, transporting, and storing
topsoil and overburden; constructing fences, berms,
buffer zones, roadways, and sediment traps; and
constructing or installing permanent or portable
processing equipment are followed.
Mining
and Processing
Mining of crushed stone or sand and gravel is dependent
on the geologic characteristics and the extent and
thickness of the natural deposit. Open-pit mining and
quarrying are most commonly used, although some stone is
mined underground. Sand and gravel deposits above the
water table are excavated with bulldozers, front-end
loaders, tractor scrapers, and draglines. Deposits below
the water table, including stream and lake bed deposits
may be excavated with draglines or from barges using
hydraulic or ladder dredges. Mining and quarrying stone
generally require drilling and blasting, after which the
rock is then transported to a processing facility on
trucks and conveyors.
Processing plants are generally constructed on the site
of extraction. Processing of mined or quarried rock
requires primary and possible secondary crushing,
depending on the sizes of aggregate needed. After
crushing, the crushed stone and sand and gravel usually
are sorted to size, moved by conveyors to bins or
stockpiled.
Reclamation
The goal of reclamation is to return the land to a
beneficial use. By planning reclamation before the
aggregate is extracted, it can be mined with how the
quarry will look when it is reclaimed. This can make it
easier to turn quarries into scenic, lake-front property,
wildlife parks, golf courses, office parks, roller
coaster rides and the many other items a quarry can
eventually become. Parts of the mine can be reclaimed
while continuing on-going mining operations in some
instances.
Reclamation procedures depend on the configuration and
character of the area. Progressive reclamation typically
involves the following three steps: terracing the pit or
face walls during or after extraction, final shaping of
the area by replacing and reconfiguring the overburden,
and landscaping. Reclamation plans are most effective if
operators and planners select a strategy that satisfies
the land use needs of the community and at the same time
provides an economic incentive for the operator.
Source:
The National Energy Foundation