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Magnetic Separation

  • Definition: A process that extracts magnetically susceptible materials from a mixture using magnetic forces.

  • Application: Particularly useful in mining iron, as it is attracted to a magnet.

Flotation

  • Process: Involves placing powdered ore into an agitated and frothy slurry.

  • Separation Mechanism: Based on physical and chemical properties, some minerals/metals sink to the bottom while others attach to bubbles and rise to the top, effectively separating the valuable materials from waste.

Cyanide Heap Leaching

  • Usage: Applied for low-grade gold ore.

  • Process: Crushed rock is piled onto a leach pile, where cyanide is sprayed or dripped over the top, allowing for gold extraction.

Environmental Impacts of Irresponsible Mining

  • Negative Consequences:

    • Flooding

    • Erosion

    • Subsidence

    • Water and soil pollution

    • Damage to wildlife and habitat

  • Mitigation Measures:

    • Topsoil Replacement: Using uncontaminated soil for reclamation.

    • Reintroduction of Flora and Fauna: Restoring ecosystems post-mining.

    • Neutralizing Acidic Waters: Treating contaminated water to restore pH levels.

    • Backfilling and Sealing Abandoned Mines: Preventing hazards associated with abandoned mine sites.

    • Promotion of Environmental Awareness: Educating communities about sustainable mining practices and protection.

    • Stabilization of Slopes: Implementing measures to reduce erosion in mined areas.

Energy Resources

  • Importance: Energy is vital for human consumption across various sectors such as agriculture, transportation, residential, commercial, and industrial.

  • Types: Energy resources can be classified into two categories:

    • Non-renewable: Resources consumed faster than they can be naturally produced, e.g. coal, oil, natural gas, nuclear.

    • Renewable: Unlimited resources that can be used sustainably, e.g. solar, wind, biomass, geothermal, hydroelectric.

Fossil Fuels

  • Definition: Energy sources formed from ancient plants and organisms during the Carboniferous period (360 to 286 million years ago).

  • Types of Coal:

    • Anthracite: Hard, high-carbon coal used for heating and fuel generation.

    • Bituminous Coal: Higher quality than lignite, used in metallurgy to make coke.

    • Subbituminous Coal: Dark brown to black coal, intermediate between lignite and bituminous.

    • Lignite Coal: Soft, brown coal, lower in carbon, primarily used for electric power generation.

    • Peat Coal: First stage of coal formation, composed mainly of organic material.

Petroleum

  • Description: A yellowish-black liquid derived from the earth, refined into various fuels.

  • Formation: Formed from large quantities of dead organic matter, subjected to heat and pressure over time.

Natural Gas

  • Composition: A mixture primarily consisting of methane with smaller amounts of other hydrocarbons.

Fossil Fuel Power Generation

  • Description: Power stations that burn fossil fuels to produce electricity.

  • Process: Combustion generates heat energy, which is converted to mechanical energy to generate electricity.

Geothermal Energy

  • Description: Utilizes heat from the earth, using steam from hot water to generate electricity.

Hydroelectric Energy

  • Definition: Generates power from water in motion.

  • Process: Water flowing over dams or waterfalls turns turbines which produce electricity.

Erosion and Deposition

  • Erosion: The process of moving fragments of rocks and soil by water, ice, wind, or gravity.

    • Effects of fast-moving streams and rivers: Carry both large and small debris downstream.

    • Ice Erosion: Glaciers also contribute to erosion processes.

  • Deposition: Occurs when transported materials settle in a new location, forming features such as flood plains and deltas.

Drainage Basin

  • Description: An area drained by a stream and its tributaries, forming various drainage patterns (dendritic, radial, rectangular, trellis).

Stream Erosion

  • Factors: Controlled by stream velocity, gradient, channel shape, and roughness.

    • Abrasion and Attrition: Processes that wear down stream channels and sediments.

Floodplain and Flooding

  • Floodplain: Flat valley floors shaped by sedimentary deposits from streams.

  • Flash Floods: Sudden, high-volume floods typically triggered by intense rainfall.

Waves and Coastal Erosion

  • Effect of Waves: Waves erode coastlines due to wind-induced friction.

  • Types of Waves:

    • Constructive Waves: Low-energy waves that deposit materials along coastlines.

    • Destructive Waves: High-energy waves that erode coasts, more powerful backwash than wash.

Coastal Formations

  • Beach: Formed by deposition of sediments from waves.

  • Features:

    • Spits: Finger-like ridges extending into water.

    • Tombolo: Ridge connecting an island to the mainland.

  • Cliff Erosion: Waves create wave-cut notches, leading to cliff instability and collapse.

Caves, Arches, and Stacks

  • Formation: Erosion progresses from caves to arches, eventually collapsing to form stacks and stumps.