Lecture 18 ENVS mining

What is a rock ?

Solid aggregation of minerals

What is a mineral ?

Naturally occurring solid element or inorganic compound with crystal structure, specific composition, and distinct physical properties

What is mining ?

The systematic removal of rock, minerals, soil, or other materials from the Earth crust to extract resources of economic interest

What influences mineral distribution in Earth ?

Gradual and catastrophic geological processes

What elements are found in Earth crust ?

Silicon iron aluminum calcium potassium sodium magnesium oxygen copper zinc nickel cobalt uranium phosphorus

What are the three main rock types ?

Igneous metamorphic sedimentary

How are mineral resources distributed ?

Unevenly across the Earth

What are conflict minerals ?

Resources like tantalum and diamonds mined in conflict regions

What are examples of metals ?

Cadmium nickel copper iron lead zinc bauxite gold silver platinum uranium

What are rare earth elements used for ?

Electronics clean energy aerospace automotive defense

Examples of precious stones ?

Diamonds sapphires rubies emeralds jade

Examples of non metals ?

Asbestos phosphorus potassium sulfur gravel sand

Examples of fossil fuels ?

Coal oil natural gas

How much material will a person use in a lifetime ?

More than 1.4 million kg of minerals and fuel

What are most mined resources used for ?

Fossil fuels and construction materials

What is a metal ?

A chemical element that is lustrous malleable opaque and conducts heat and electricity

Where are metals found ?

In ores

What is an ore ?

A mineral or grouping of minerals from which metals are extracted

Example of ore ?

Coltan and pyrite

What must be done before extracting metals ?

Ores must be pulverized and washed

What is smelting ?

Process of heating an ore beyond its melting point and combining it with chemicals to extract a metal

Examples of non metallic minerals ?

Gemstones limestone salt potash

What are the most commonly mined resources ?

Sand and gravel aggregates

How were fossil fuels formed ?

From organisms that lived 100 to 500 million years ago under anaerobic conditions

What processes form fossil fuels ?

Heat and pressure

Types of fossil fuels ?

Coal oil natural gas

What is coal ?

The most abundant fossil fuel

Where is coal found ?

In coal seams within ore

What is a coal seam ?

A concentrated layer of coal

What is mining activity ?

Removal of surface rock soil or material to extract coal deposits

What is strip mining ?

Heavy machinery removes large amounts of earth to expose and extract resources

What does strip mining create ?

Open pit mines

What is subsurface mining ?

Underground mining using vertical shafts and horizontal tunnels

How deep can subsurface mines go ?

Nearly 4 km underground

What are the main environmental impacts of mining ?

Strip mining subsurface mining waste rock tailings acid mine drainage mountaintop mining air pollution

What are impacts of strip mining ?

Destroys habitats causes erosion and pollutes surface and groundwater

Why is subsurface mining dangerous ?

Dynamite blasts tunnel collapse toxic fumes and coal dust

What are long term effects of subsurface mining ?

Acid drainage polluted groundwater and sinkholes

What is waste rock ?

Non valuable material removed before extraction

What is another name for waste rock ?

Overburden

What are tailings ?

Material left after extraction of coal or metals

Why are tailings dangerous ?

They contain heavy metals and acids and can pollute soil water and air

What is leachate ?

Toxic liquid formed when water carries dissolved pollutants

What causes acid mine drainage ?

Sulfide minerals forming sulfuric acid

What happens during acid mine drainage ?

Acid flows into water and releases toxic metals

What is mountaintop mining ?

Blasting entire mountaintops and dumping waste into valleys

What are environmental impacts of mountaintop mining ?

Deforestation erosion flooding pollution and habitat destruction

What are social impacts of mountaintop mining ?

Damaged homes health problems contaminated water

What pollutants come from coal ?

Sulfur mercury arsenic lead and other trace metals

What does burning coal cause ?

Smog and acid deposition

What happens to mercury in ecosystems ?

It bioaccumulates and biomagnifies through food chains

What is reclamation ?

Restoring mined land to a condition similar to pre mining state

What are companies required to do in Canada before mining ?

Post bonds to cover reclamation costs

What are steps in reclamation ?

Remove structures replace overburden fill shafts replant vegetation

Why is reclamation imperfect ?

Ecosystems become simplified and not fully restored

What happens to biodiversity after reclamation ?

It is reduced

What ecosystems are replaced after mining ?

Forests and wetlands replaced by grasses

Can water be restored after mining ?

Yes by removing heavy metals and adjusting pH

Do all mining methods have similar impacts ?

Yes they all cause environmental damage

What is needed short term for mining ?

Modify methods to reduce impacts

What is needed long term for mining ?

Find alternatives to mined resources

What increases global mining impact ?

High consumption and increasing population

What economic change is happening in mining ?

Including environmental costs in products

What are sustainable alternatives to mining ?

Recycling reprocessing and alternative materials