308 CHAPTER 12 Mineral and Soil ResourcesNewsComof the resulting acid precipitation are discussed in Chap-
ter 9.) Pollution control devices for smelters are the same
as the devices used for the burning of sulfur-containing
coal—scrubbers and electrostatic precipitators.
Contaminants in ores include the heavy metals lead,
cadmium, arsenic, and zinc. These toxic elements may
pollute the atmosphere during the smelting process and
cause harm to humans. Smelters emit airborne pollut-
ants as well as hazardous liquid and solid wastes that can
pollute the soil and water.
One of the most significant environmental impacts
of mineral production is the large amount of energy re-
quired to mine and refine minerals, particularly if they
are being refined from low-grade ore. Most of this en-
ergy is obtained by burning fossil fuels, which depletes
non-renewable energy reserves and produces carbon di-
oxide and other air pollutants.
Restoration of Mining Lands
When a mine is no longer profitable to operate, the land
can be reclaimed, or restored to a seminatural condi-
tion, as has been done to most of the Copper Basin in
Tennessee (see the chapter introduction). Reclamation
prevents further degradation and erosion of the land,
eliminates or neutralizes local sources of toxic pollutants,
and makes the land productive for purposes other than
mining (Figure 12.10). Restoration also makes such ar-
eas visually attractive.
A great deal of research is available on techniques
of restoring land degraded by mining, called der elict
land. Restoration involves filling in and grading the area
to the shape of its natural contours and then planting
vegetation to hold the soil in place. The establishment of
plant cover is not as simple as throwing a few seeds on the
ground. Often the topsoil is completely gone or contains
toxic levels of metals, so special types of plants that toler-
ate such a challenging environment must be used, such
as acid-tolerant species. According to experts, the main
limitation on the restoration of derelict lands is not a lack
of knowledge but the lack of funding.
The Surface Mining Control and Reclamation Act
of 1977 requires reclamation of areas that were surface
mined for coal. However, no federal law is in place to
require restoration of derelict lands produced by other
kinds of mines. As a result, restoration of mining lands
often does not occur.,iÃÌÀ>ÌÊvÊ}Ê>`ÃÊUÊ}ÕÀiÊ£Ó°£ä
Bull elk forage on a reclaimed surface coal mine in Hindman, Kentucky. Restoration of mining lands
makes them usable once again, or at least stabilizes them so that further degradation does not occur.- What are three harmful environmental effects
of mining and processing minerals? - How are mining lands restored?
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