Mining Reading

Mining Reading

  • Modern Mining: An industry that involves the exploration for and the removal of minerals from the earth, economically and with little damage to the environment

  • Non-fuel minerals

    • Stone; Sand; Salt (Non-metallic/industrial mineral)

    • Metallic minerals

      • Are combined in nature with other materials as ores (bauxite ore → aluminum)

      • Usually treated with chemicals or heat to produce the metal of interest 

  • Fuel minerals

    • Coal

    • Uranium

    • Processed using chemicals

  • Factors Affecting Global Mining

    • Environmental regulations

    • Fuels costs

    • Labor costs

    • Access to land that contains valuable ore

    • Technology

  • Mining Life Cycle

    • Exploration

      • Determine the location, size, shape, position, and value of ore body by geologic mapping and field investigations, remote sensing through satellites, or drilling

      • Building access roads to a drilling site causes environmental damage

    • Development

      • Conducting a feasibility study

        • Financial analysis

      • Designing the mine

      • Acquiring mine rights

      • Filing an Environmental Impact Statement (Part of NEPA)

      • Preparing the site for production

    • Extraction + Processing

      • Remove overburden

      • Removal of ore from the ground through

        • Surface Mining

        • Underground Mining

        • In Situ (Extraction using chemical solutions)

      • Crushed after removal so the valuable minerals can be separated from the waste material and concentrated by flotation (a process that separates finely ground minerals from one another causing material to either sink or float), gravity, magnetism, or other processing methods

      • Production of large amounts of waste (acidic) leads to major health and environmental concerns 

    • Mine closure

      • Cessation of mining at the site

      • Completion of a reclamation plan

      • Ensures the safety of areas affected by the operation 

        • Sealing entrance to the mine

      • The Surface Mining and Control Act of 1977

        • Reclamation must restore the land affected to a condition capable of supporting the uses that it was capable of supporting before mining

      • Abandonment → Health-related hazards 

  • Three types of mining

    • Surface Mining

    • Underground Mining

    • In Situ (Extraction using chemical solutions)

  • Environmental Impacts

    • Air

      • Particulate matter is released in surface mining

        • Arsenic, Cadmium, Lead

      • Soil + vegetation removed → Soil exposed to weather → Particles become airborne through wind erosion and road traffic

      • Particles affect human health by contributing to illnesses relating to the respiratory system; can also be absorbed into the skin

    • Land

      • Physical disturbances to the landscape

        • Eyesores (Waste-rock piles and open pits)

      • Decline of wildlife and plant species

      • Premining surface features can’t be replaced

      • Mining subsidence (Ground movements of the earth’s surface due to the voids created by mining) causes damage to buildings and roads


  • Water

    • Acid mine drainage

      • Formation is a function of the geology, hydrology, and mining technology employed at a mine site

      • Primary sources: sulfide minerals, pyrite (iron sulfide) (Decomposable in air and water)

      • Water infiltration of pyrite-laden rock in the presence of air causes it to become acidified

      • Acid mine drainage destroys living organisms, corrodes culverts, piers, boat hulls, pumps, and other metals, and renders the water unacceptable for drinking or recreational use

      • Pyrite + Oxygen + Water → “Yellowboy” + Sulfuric Acid

        • Yellowboy = Iron and aluminum compounds that stain streambeds

      • Enters environment through free-draining piles of waste rock that are exposed to intense rainstorms; groundwaters that enter underground workings which become acidic; acidic tailings containment ponds (waste materials)

    • Metal contamination

    • Increased sediment level in streams

    • Sources: Abandoned and active mines; processing plants; waste-disposal areas; haulage roads, tailings ponds

    • Sediments cause siltation (the process of blocking something with sand or soil) of streambeds

  • Major U.S Mining Laws

    • Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); Known as Superfund 1890

      • Requires operations to report releases of hazardous substances to the environment and requires clean up or sites where the substances are found

    • The Federal Water Pollution Control Act 1977 (Clean Water Act)

      • Requires mining operations to meet standards for surface water quality and for controlling discharges to surface waters

    • The Resource Conservation and Recovery Act 1976 (RCRA)

      • Regulates the generation, storage, and disposal of solid waste and hazardous waste using a “cradle to grave” system

        • These wastes are governed from the point of generation to disposal

    • The National Environmental Policy Act 1970 (NEPA)

      • Requires federal agencies to prepare an environmental impact statement for major federal actions that may significantly impact the environment

  • Human Hazards 

    • Traces of lead, zinc, cadmium, silver, and gold

    • Lead found in blood → Learning and behavioral problems, seizures, comas, and even death

    • Metals contaminated soils, surface waters, groundwater, and air 

    • Children are at greater (more vulnerable because they retain the lead more)

    • Asbestos → Lung cancer, Mesothelioma (Cancer)

      • Still current issue (controversial) 

  • Coal-Bed Methane

    • Potent greenhouse gas trapped inside coal, released when coal is mined

    • Coal-bed methane used for energy

      • Reduce methane and CO2 emissions overall (burning coal produces less carbon dioxides than burning fossil fuels)

    • Methane has been discovered in groundwater in residential areas