Useful metals come from rocks and minerals in the Earth

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Useful metals come from rocks and minerals in the
Earths crust.
Image G. Plumlee, USGS
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Mining of metal-bearing rocks also requires
removing less valuable rocks - waste rocks.
Image Kennecott Utah Copper Co.
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Separating metal-bearing minerals from others
produces waste called tailings.
Image Kennecott Utah Copper Co.
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Environmentally sound disposal of waste rock and
tailings is needed to protect soil and water
resources.
Before
After
Images Gold Institute, Echo Bay Mines S. Warren
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Environmentally sound disposal of waste rock and
tailings commonly uses soil covers that prevent
erosion and development of acidic waters (acid
rock drainage).
Revegetated Pile Surface
Soil Growth Medium
12
Uncompacted Lime - amended wasterock
12
Compacted consolidated wasterock
Image Kennecott Utah Copper Co., DeAtley Design
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In some cases, covering tailings with water
prevents acid rock drainage and creates valuable
habitat.
Before
After
Images Kennecott Utah Copper Co.
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Historically, mineral processing to recover
metals from minerals emitted large amounts of
harmful gases and particles to the atmosphere.
Image Atlantic Richfield Company
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Modern facilities to recover metals from minerals
use new technology that reduces emissions below
those permitted by regulatory agencies.
Discharges at Kennecott smelter in Utah.
Comparison units in metric tonnes.
Acid Mist 151 Acid Mist 48
Particulates 728 Particulates 400
SO2 - 20,050 SO2 982
1992 Modernized (Permitted)
Smelter
Image Kennecott Utah Copper Co., DeAtley Design
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Metals we need can be provided in environmentally
sound ways.
Image Digital Vision
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