Useful metals come from rocks and minerals in the Earth’s crust. Image: G. Plumlee, USGS Metals-1-1

Mining of metal-bearing rocks also requires removing less valuable rocks - waste rocks. Image: Kennecott Utah Copper Co. Metals-1-2

Separating metal-bearing minerals from others produces waste called “tailings”. Image: Kennecott Utah Copper Co. Metals-1-3

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 Metals-1-4

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 Metals-1-5

In some cases, covering tailings with water prevents acid rock drainage and creates valuable habitat. Before After Images: Kennecott Utah Copper Co. Metals-1-6

Historically, mineral processing to recover metals from minerals emitted large amounts of harmful gases and particles to the atmosphere. Image: Atlantic Richfield Company Metals-1-7

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 Metals-1-8

Metals we need can be provided in environmentally sound ways. Image: Digital Vision Metals-1-9