Mining Process What are the environmental implications What

Mining Process What are the environmental implications?

What is an Ore? Definition – a rock that contains a large enough concentration of a particular mineral – often a metal – that the rock can be mined and processed to extract the desired mineral Example: Bauxite – Aluminum High vs. Low Grade

Removing Mineral Deposits Two Types: • Subsurface Mining • Expensive • Dangerous • Lower Environmental Impact • Surface • Cost Effective • Safe • High Environmental Impact

Mining For Minerals and Coal Extraction Subsurface: • Mine Shafts • Room-and-Pillar • Longwall Mining Surface: • • Open Pit Strip Mining Contour Strip Mining Mountain Top Removal

Open Pit Mining Open Pit Mine

Area Strip Mining

Contour Strip Mining

Open Pit Copper Mine

Mining Impacts • Disruption of land surface • Habitat Fragmentation • Subsidence • Toxic-laced mining wastes – Gangue/Tailings

Acid Mine Drainage • Acidification of: • Soil • Groundwater • Surface water • Increased Solubility of Metals: • Aluminum • Mercury • Decreased Plant Growth/Animal Distribution

Processing • Smelting: – Releases Air Pollution • Sulfur Dioxide • Suspended particles • Cyanide Heap Leaching

Surface Mining Control and Reclamation Act - 1977 • Requires mining companies to restore most surface mined land • Reclamation Process: 1) Recontouring/Regrading 2) Replacing topsoil/nutrients 3) Replanting native/fast growing vegetation 4) Monitoring for 5 -10 years

Specific To Coal • Cover Tailings to prevent leaching • Sedimentation Ponds/Retention Basins/Catchments • Bioremediation • Liming/Calcium Carbonate Buffers