Mining, Ores and Minerals

• Rocks are solidified magma comprised of two or more minerals.
• Minerals are naturally occurring, inorganic substances found in the Earth's crust.
• Ores are minerals containing a sufficient amount of an element to make extraction profitable, hematite contains iron-oxide.

Compounds vs. Elements

• Compounds are mixtures, whereas elements are pure substances.

Mining

• Mining involves extracting ores or minerals from the ground.

Impacts of Mining

• Deforestation, pollution, and contamination are impacts of mining due to the use of excavators and bulldozers.

Reasons for Mining

• Mining is driven by profit, provides jobs and supports civilization.

Mining Method

• Surface mining, open cut mining, dredging, underground mining, petroleum wells, and leach mining are the different methods of mining.

Dependent Factors

• The cost of the mineral, the type of mineral, and the geology of the area.

Mineral Ores

• Casserite is the ore for Tin (Sn).
• Bauxite is the ore for aluminum (Al).
• Culprite is the ore for copper (Cu).
• Hematite and magnetite are the ores for Iron (Fe).
• Galena is the ore for lead (Pb).
• Cinnabar is the ore for mercury (Hg).

Properties of Minerals

• Hardness, luster, color, shape, and streak.

Exploration

• Exploration identifies mineral resources or deposits beneath the Earth's surface through geological surveys and sampling.

Types of Exploration

• Aerial methods, on-site methods, satellite imaging, and geological maps.

Aerial Methods

• Uses aircraft or helicopters to quickly survey vast areas.

Types of Aerial Methods

• Magnetic surveys, gravity surveys, and electromagnetic surveys.

Magnetic Surveys

• Detect changes in Earth's magnetic field using magnetometers.
• Maps display variations in color, assisting in locating iron, nickel, and cobalt.

Gravity Surveys

• Gravimeters measure tiny disruptions in Earth's gravity caused by denser rocks and minerals.
• Maps display gravity differences, revealing underground features.

Electromagnetic Surveys

• Detect metal ores that conduct electricity, using a transmitter to send a magnetic field.
• Eddy currents in minerals produce a new magnetic field, detected by a receiver and helpful in finding copper, lead, zinc, gold, and silver.

On-Site Methods

• Provide more specific data than aerial methods.

Types of On-Site Methods

• Seismic surveys and geochemical surveys.

Seismic Surveys

• Send shock waves into the ground and maps underground structures based on how sound waves bounce back.

Geochemical Surveys

• Chemistry identifies minerals through core samples.
• Finding one mineral suggests presence of others nearby like gold with uranium, arsenic, and antimony.

Satellite Images

• Satellites capture photos of Earth, detecting invisible light rays like near-infrared, shortwave-infrared, and thermal-infrared radiation.
• Reveals landscape features hidden in normal photos.

Geological Maps

• Maps mining areas using aerial, on-site, and satellite methods.
• Shows underground rock layers in cross-section or bird's-eye view.

Open Pit Mining

• Used for ore bodies close to the surface
• Drilling and blasting create an open working surface.
• Open-cut pits are made with roads and giant drills and large machines that remove ore.
• Mining stops when the pit is too deep, expensive, or difficult to continue.
• In Australia, open pit mines extract gold, zinc, and copper.
• Fimiston open pit in Kalgoorlie, WA, is the largest open-cut gold mine.

Leach Mining

• Injects fluids into the ore body to dissolve materials; solution is called leach solution.
• Involves drilling holes into the ore deposit.
• Dissolved ore is pumped to the surface for extraction, extracting minerals without removing the rock itself.
• Used to mine uranium.

Dredging Method

• Dredging boat uses a dredge (large hose or bucket scoop) to collect material, mostly sand, from the bottom.
• Heavier minerals are separated light sand.
• The sand and water are pumped back into the lake.
• Used when ore is near water
• Typically used for titanium materials.
• Cooljarloo mine in Cataby, WA, mines titanium materials using dredging.

Underground Method

• Used when ore is deep, concentrated, confined, or surface mining is inappropriate.
• A decline path allows trucks to drive down and collect crushed ore.
• Slopes are drilled and blasted, then copper ore is loaded and hauled to an underground crusher and conveyor system.
• Used for gold, nickel, copper, uranium, diamond, silver, lead, zinc, and tin.
• Birla Nifty copper mine, in the Great Sandy Desert, mines chalcopyrite ore using the underground technique.

Petroleum Wells Method

• Drills deep into the earth to reach the oil or gas.
• The earth's natural pressure forces the oil and gas up through the hole to storage tanks.
• Extracts crude oil and natural gas.

Steps to Obtaining Materials

• Mining removes resources.
• Processing removes unnecessary materials and extracts desired materials.
• Rehabilitation repairs the mining site to resemble its original environment.

Steps of Processing

• Crushing ore to a uniform size increases its surface area for further treatment.
• Magnetic minerals are separated by magnets; dense materials drop out naturally.
• Minerals are enriched to concentrate and improve their quality.
• Desired metals are extracted which is a chemical process.
• Iron, lead, and zinc can be extracted by heating them in a blast furnace.

Rehabilitation

• Open-cut mines require rehabilitation to restore the environment.
• The original topsoil is replaced.
• Graded to ensure proper drainage and fertilized.
• Replanted with native plants.

Tailings

• Waste materials from the mine or processing plant.
• Contain toxic acids or poisonous chemicals.
• Dumped into ponds surrounded by earth walls, which could destroy the ecosystem.

Mining Regulation

• Mining companies follow strict laws and regulations and designs for controlling pollution.
• Water pollution is managed by chemically treating the water and letting it settle in tailing dams.
• After treatment, clean runoff is safely released into nearby creeks and rivers.