Mining

• Rocks in the Earth's crust

  Provide metals, minerals and fuel resources
• Geological processes

  • Gradual and catastrophic processes influence distribution of rocks and minerals in the Earth's crust (lithosphere) and their availability
• Rock

  Solid aggregation of minerals
• Mineral


  A naturally occurring solid chemical element or inorganic compound with a crystal structure, a specific chemical composition, and distinct physical properties
• Mining


  The systematic removal of rock, minerals, soil, or other materials from the Earth's crust for the purpose of extracting resources of economic interest
• Earth's crust composition

  • Chemical elements
  • Rock types (ores, minerals)
• Chemical elements in Earth's crust

  • silicon
  • iron
  • aluminum
  • calcium
  • potassium
  • sodium
  • magnesium
  • oxygen
  • copper
  • zinc
  • nickel
  • cobalt
  • uranium
  • phosphorus
• Rock types in Earth's crust

  • Igneous rocks (metals)
  • Metamorphic rocks (marble)
  • Sedimentary rocks (aggregates, minerals)
• Metal and Mineral Resources are Distributed unevenly
• Some resources (e.g. tantalum and diamonds from DRC - Democratic Republic of the Congo) are considered conflict minerals
• Mined resources

  • Metals
  • Rare Earth Elements
  • Precious Stones
  • Non-metals
  • Fossil Fuels
• Rare Earth Elements

  • neodymium
  • europium
  • terbium
  • dysprosium
  • yttrium
  • tantalum
• Precious Stones


  • diamonds
  • sapphires
  • rubies
  • emeralds
  • jade
• Non-metals

  • asbestos
  • phosphorus
  • potassium
  • sulfur
  • gravel
  • sand
• Many items we use everyday are made from elements mined from the Earth
• Items made from mined elements

  • Silica and lithium in glasses
  • Aluminum in can
  • Gypsum in wallboard
  • Tungsten in lightbulb
  • Iron in pen ink
  • Zinc and manganese in batteries for a radio
• At current rates of use, a child born in 2015 will use more than 1.4 million kg of minerals and fuel during their lifetime
• Most of this is for fossil fuels and construction materials
• Metal


  A type of chemical element, that typically is lustrous, opaque, and malleable, and can conduct heat and electricity
• Most metals are not found in a pure state in nature
• Ore


  A mineral or grouping of minerals from which metals are extracted
• Ores


  • coltan (tantalum)
  • pyrite (gold, silver, nickel, copper, zinc, uranium)
• Metals and Rare Earth Elements processing after Mining

  1. Ores must be pulverized and washed

  2. Desired metals/minerals can be physically or chemically extracted

  3. Smelting - process of heating an ore beyond its melting point and combining it with other chemicals to extract a metal
• Non-metallic minerals

  • gemstones
  • limestone (calcium carbonate)
  • salt (sodium chloride)
  • potash (source of potassium)
• Sand and gravel aggregates are the most commonly mined mineral resources
• Similar mining technologies are used for all resources with similar environmental problems resulting
• Fossil fuels

  Formed under anaerobic environments (in absence of oxygen) from organisms that lived 100 to 500 million years ago
• Types of fossil fuels

  • coal
  • oil
  • natural gas
  • others
• How coal is formed

  1. Dead plant matter fell in swampy water, over time more dirt and water washed in which halted the decay process and formed peat

  2. The layers of water and dirt packed down the layers and under heat and pressure, oxygen was pushed out, forming coal
• Coal mining

  Similar to most other mining activities (e.g. for metals and minerals) - extractive process
• Coal seam


  The rock in which valuable materials have been concentrated over time by geological processes - typically in minerals like quartz, clays, feldspars, sulfides, and carbonates
• Mining Activity


  1. Systemic removal of surface rock, soil, or other material to extract buried coal deposits

  2. Mining focuses on highest concentrations of coal in surface or underground "coal seams"
• Types of Mining Methods for Coal


  • Strip Mining
  • Subsurface Mining
• Strip Mining


  Heavy machinery removes huge amounts of earth to expose and extract resource
• Open pit mines

  Massive because of the amount of waste rock that must be removed to extract small amounts of ore of economic interest
• Subsurface Mining

  Underground deposits reached by digging vertical shafts deep underground and excavating networks of horizontal tunnels that are dug or blasted out to follow the underground ore deposits containing minerals/metals
• Environmental and Human Health Impacts of Coal and Metal Mining

  • Water-intensive
  • Energy-intensive
  • Mining accidents
  • Black lung
  • Lung cancer
  • Strip mining / open-pit mining
  • Subsurface mining
  • Waste rock (gangue)
  • Tailings
  • Acid mine drainage (AMD)
  • Mountaintop mining
  • Air pollution
• Strip Mining or Open Pit Mining

  • Layers of soil and rock are removed to expose the resource
  • Overlying soil and rock is removed by heavy machinery
  • Used for coal, oil sands, sand, gravel and some metals
  • Destroys natural communities over large areas and triggers erosion and habitat loss, surface and groundwater pollution
• Subsurface Mining

  • Commonly used with coal
  • Deepest mines extend nearly 4 km underground
  • Most dangerous form of mining - dynamite blasts, collapsed tunnels, toxic fumes, coal dust
  • Subsurface mines can affect people years after they close - acid drainage, polluted groundwater, sinkholes - damage roads and homes, etc.
• Waste Rock (Gangue)

  • Waste rock and non-valuable minerals removed before extraction (= overburden)
  • Used for roads, railbeds, dams