Trace-Element Geochemistry of Coal Resource Development Related to Environmental Quality and Health (1980) / Chapter Skim
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COAL MINING
COAL MINING
Pages 39-56
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From page 39... ...
Similarly, in surface mines, the removal and handling of the overburden provides for the dissolution and migration of the contained trace elements. SURFACE MINING Surface mines in the three western coal provinces (Northern Great Plains, Rocky Mountain, and Gulf Coastal Plain)
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From page 40... ...
In the coal provinces of the Northern Great Plains, Rocky Mountains, Gulf Coastal Plain, and the Eastern and Western Interior, many economically significant coal beds are nearly horizontal beneath level to gently rolling surface terrain. Mining normally begins near where the coal outcrops at the surface, where the overburden is thin, then continues into thicker overburden until physical or economic limits of mining are reached.
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From page 41... ...
and the upper solid line (representing the original surface) indicates the large amount of grading that is required to meet the standards for restoration in Part 816.102 of the 1977 Surface Mining Control and Reclamation Act (Office of the Federal Register, 19781 U.S.
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From page 42... ...
In other coal provinces or where the terrain is hilly, contour mining prevails. Contour mining commences where the coal bed and surface elevations coincide and proceeds along the outcrop of the coal bed.
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From page 44... ...
The practices and explosives used ar similar to those described for overburden removal. Coal extraction in surface mine is almost exclusively accomplished by small shovels cbucke capacity up to about 30 ml)
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From page 45... ...
In some mines, the floors of underground mines heave upward, thereby reducing the amount of subsidence, but subsidence, in some degree, occurs above practically all underground coal mines. As controlled roof caving occurs, subsiding rock fills the void left from coal extraction with less dense material.
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From page 46... ...
In the late 1960's, AMD was especially serious in the eastern half of the country, where over 10,500 miles of waterways were being degraded by acid drainage and 200,000 acres of land became barren or infertile because of refuse disposal and acid runoff (Ohio Basin Regional Federal Water Pollution Control Administration, 1969)
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From page 47... ...
Inactive surface mines contributed 11 percent of the AMO in the Appalachia inventory, and active surface mines contributed 1 percent (Ohio Basin Regional Federal Water Pollution Control Administration, 1969)
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From page 48... ...
Postmining Spoil and Overburden Drainage Final or initial cuts can serve the useful purpose of surface water storage. In this case, the edge of the coal seam at the base of a "highwall" is covered by impermeable sediment to prevent direct contact between the coal and the stored water.
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From page 49... ...
The mining process, apart from overburden removal, coal extraction, and coal preparation, also produces wastes that must be handled. In a surface mine, these wastes result from cleaning the top of an exposed coal seam before the coal is removed.
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From page 50... ...
New or different sources and amounts of trace elements are made available to veqetation, and their potential beneficial or detrimental effects should be assessed throuqh controlled environmental or aqricultural studies on test plots on reclaimed land with careful sequential chemical analysis of product qrowth. Disturbed areas include not only reqraded areas of actual surface mininq but also areas at abandoned mines where facilities and haul roads and/or access roads are removed.
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From page 51... ...
Topsoil handlinq, overburden removal and replacement, coal extraction, reveqetation, and subsidence may influence trace-element redistribution. Redistribution can occur throuqh one or more of the followinq processes: • Physical relocation.
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From page 52... ...
The qradinq operation relocates trace elements occurrinq in the oriqinal overburden. This relocation is a minor effect, as is overburden removal, compared to the potential and actual redistribution of trace elements by oxidation and water-solubilization processes occurrinq at the microenvironmental levels.
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From page 53... ...
The interdependence of overburden characteristics, the availability and composition of qroundwater as a transport medium, and the method of overburden removal and replacement make the analysis of potential redistribution of trace elements a site-specific problem. HEALTH EFFECTS Occupational Health Inhalation of coal dust and concomitant trace-metal exposure from surface mininq have not been shown to be hazardous.
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From page 54... ...
A lonq-ranqe study of lunq tissue from deceased bituminous coal miners from West Virqinia compared metal concentrations between miners and nonminers and examined the relationship of total dust, free silica, and trace-metal concentrations to severity of CWP (Sweet et al., 1974)
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From page 55... ...
The high acidity and increased corrosiveness might interfere with water treatment processes, such as coagulation and softening, although the mineral content can usually be reduced by additional treatment. The direct public-health effects of increased metal concentrations in drinking water are unclear, especially as only a small fraction of the daily intake of elements reaches the human body through drinking water (Table 12)
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From page 56... ...
. Comprehensive studies of radionuclides in coal mine drainage have not been undertaken, but some measurements have been reported (Caldwell et al., 1970)
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