1.2

• Whays of exploring for minerals:

  • Prospecting
  • Remote Sensing
  • Radiation Detection
  • Satelite Signals
  • Satelite Imagery
  • Geochemical Analysis
  • Geophysics
• Methods of Extraction

  • Sub Surface Mining
  • Surface Mining
• Prospecting

  A process of searching for minerals by examining the surface of rocks.
• Remote Sensing

  A Process in which information about the earths surface is gathered from above through:

  • Taking photographs
  • Analysing the images for mineral presance
• Radiation Detection

  Mineral deposits are weathered at the earths surface forming mineral oxides. They can be detected by their unique radiation pattern
• Satelite Signals

  Satelites send signals to the earth, and collect the reflected signals indicating the presance of minerals. This system works in all weather conditions.
• Satelite Imagery

  Computers are used to process the data from a region of interest to check for mineral presance. The presance is confirmed by geologists visiting the region. The goelogists can further check the availability of the resource in the given area.
• Geochemical Analysis

  Done by analysing the chemical properties of rocks by taking samples.
• Geophysics

  A method of identifying mineral ores present in rocks using their physical properties. This is done by sending vibrations through the earths surface forming a shock wave. This wave bounces back recording different patterns based on the minerals in the rock layers.
• Surface Mining

  Open pit mining is used when a valuable deposit is located near the surface. Vegetation is cleared and the topsoil is removed. Rocks are loosened with explosive and removed using diggers. The rock or mineral is tipped into trucks or railway wagons. Building materials such as sand stone or gravel are removed from open pits called quarries. This method is mainly used to mine coal
• Sub Surface Mining

  A vertical shaft is sunken deep into the rock layer containing minerals. A horizontal tunnel is made, following the mineral layer. The minerals are extracted by digging (by machines and miners). The loose rock from the mine is piled up on waste heaps on the surface. The minerals are brought up to the surface and put on trains or trucks.
• Factors that affect the decision to extract rocks and

  minerals - The costs of exploration and extraction:

  • There are fewer technical difficulties of mining on a large scale using open pit mining as there would be low extraction cost per tonne
  • Shaft mining is costlier to set up and maintain as the CPT will be higher. So only deposits of higher value can be mined there.
• Factors that affect the decision to extract rocks and

  minerals - Geology:

  • High grade ores yield more of the required chemical elements than low grade ones
  • Small deposits of high grade or are worth mining
  • Small deposits of low grade ores are not mined and are left as reserves
• Factors that affect the decision to extract rocks and

  minerals - Accessibility

  • Transporting ore from the mine to the processing plant can be difficult and expensive
  • The cost of building road links and rail links to processing plants or ports needs to be concidered
  • The mining company needs to get a license before extracting a deposit
  • A Long term agreement between the mining company and government needs to be agreed on to avoid rapid rise of tax which would make mining unprofitable
• Factors that affect the decision to extract rocks and

  minerals - Environmental impact assessment:

  • For license applications to be approved companies must provide a plan to keep loss of habitat minimal.
  • The choice of site for mine waste should be considered
• Factors that affect the decision to extract rocks and

  minerals - Supply and demand:

  • Increase in demand for a certain mineral ore will raise prices
  • The profit from working a mine depends on changes in supply and demand
  • If demand is high, mines that were not profitable to mine before become worth mining.