Mining: Types, Processes, and Impacts

Introduction to Mining

• Mining involves extracting finite resources (minerals, ores) from Earth.
• Resources are unevenly distributed globally due to Earth's formation and plate tectonics.
• Uneven distribution can lead to environmental and social consequences, e.g., child labor in Tanzanian mines for gemstones.

Basics of Ore

• Ore: Rock containing economically valuable minerals.
• Deposits: Locations with a high concentration of ore.
• Reserves: Economically recoverable amount of ore.
• Gangu: Unusable part of the ore, often discarded as tailings.
• Smelters: Machines that separate ore from non-usable materials, known for pollution and high energy use.

Types of Mining

• Surface Mining: Extracts materials close to Earth's surface.
  • Mountaintop Removal: Uses explosives to remove mountaintops.
  • Strip Mining: Removes large surface areas, easier to reclaim.
  • Open Pit Mining: Involves large, deep pits.
  • Placer Mining: Sifting through sediment in rivers, causing erosion.
• Subsurface Mining: Extracts materials deep underground, typical in coal mining.

Surface Mining Techniques

• Mountaintop Removal: Destroys mountain tops to access minerals, fills valleys with debris.
• Strip Mining: Involves shallow excavations, large environmental footprint but better for reclamation.
• Open Pit Mining: Creates expansive pits, significant landscape alteration.
• Placer Mining: Causes erosion and sedimentation in water bodies.

Subsurface Mining

• Involves digging deep to access resources over 100 meters below the surface.
• Modern mining uses machines rather than manual labor.

Environmental Impacts

• Surface Mining:
  • Damages landscapes and habitats.
  • Causes water pollution from sediment and toxins.
  • Air pollution from dust and explosives.
• Subsurface Mining:
  • Has less surface environmental impact.
  • Causes acid mine drainage, affecting water pH and aquatic life.
  • Health risks to miners due to toxic inhalation.

Regulation and Reclamation

• Surface Mining Control and Reclamation Act: Requires reclamation of surface mines.
• Reclamation Steps:
  • Backfill excavated areas.
  • Recontour land to original state.
  • Introduce topsoil and plants.
  • Maintain and ensure erosion control.
  • Maintenance period: 5 years in the East, 10 years in the West due to drought concerns.

Conclusion

• Mining processes have distinct methods and environmental impacts.
• Reclamation efforts aim to mitigate these impacts and restore landscapes.
• Future discussions on sustainable mining practices are essential for minimizing environmental damage.