Lithosphere

• What are the five mineral resources that are produced in the largest quantities?

  Aggregates, Iron, Limestone, Salt (sodium chloride) and Gypsum (China clay).
• Which minerals will be important for renewable energy?

  Lithium, cobalt, copper and nickel.
• What is hydrothermal deposition?

  Igneous intrusions produce pressurised superheated water at high temperatures that dissolve many minerals from the surrounding rocks. The mineral-rich solutions travel along fissures away from the igneous batholith, cooling as they do so.
• What is deposited from hydrothermal deposition?

  Metal ores are deposited by hydrothermal processes, these include: tin, copper, lead, silver, gold, and arsenic.
• What are Proterozoic sediments?

  These include iron ore deposits such as hematite and magnetite. Formed when dissolved iron compounds became oxidised by the oxygen released by photosynthesis producing Insoluble iron oxide deposits.
• What are alluvial deposits?

  Alluvial processes involve materials that were carried and separated by flowing water. the ability of water to carry solids depends upon the velocity of water and the density of the solids.
• What minerals are exploited from alluvial deposits?

  Gold, diamonds, tin ore, gravel, sand, and clay.
• How are evaporites formed?

  if a bay of an ancient sea becomes isolated, then the water may have evaporated leaving crystallised minerals such as halite.
• What is secondary enrichment?

  Many economically important metals can form minerals that are soluble or insoluble depending upon the conditions, especially the availability of oxygen. They may be transported in solution, by moving water, and then deposited as their oxidation stat changes.
• What are biological sediments? 


  Biological processes are those where living organisms form mineral deposits. These can be deposited in sedimentary rocks.
• What is Lasky’s Principle?

  Lasky’s principle states that: in general, as the purity of a mineral decreases, the amount of the mineral present increases exponentially. So, the major problem with future mineral supplies is not the quantity that exists but the need to develop methods to exploit low-grade deposits. 
• What factors affect mining viability?

  Ore purity, chemical form, overburden & hydrology, depth, cut-off ore grade, transport costs and market economics.
• Bioleaching


  The use of living organisms to extract metals from their ores
• Acidophilic bacteria


  • Can be used to extract metals such as copper, zinc, lead, and gold from low grade sources
  • Oxidise sulphide ores and produce sulfuric acid which dissolves the metals
• Metals extracted by acidophilic bacteria


  • Copper
  • Zinc
  • Lead
  • Gold
• Aspergillus fungi


  • Can be grown on scrap electronic components, fly ash from incinerators and catalytic converters
  • Produce acids that dissolve metals such as nickel, lead, copper, and tin
• Metals extracted by Aspergillus fungi


  • Nickel
  • Lead
  • Copper
  • Tin
• Separation of metals in the solution produced by bioleaching

  1. Electrolysis

  2. Using carbon filters
• What is Phytomining?


  Some plants absorb metal ions from soil or water and concentrate them in their leaves. This can be used as a method of decontaminating polluted sites and as a method of commercial extraction of metals. Once the plants have absorbed the metals, the vegetation is harvested and incinerated. The concentrated metals in the ash can be dissolved using acids, then separated by electrolysis.
• What are Polymer nodules?

  Polymetallic nodules:

  These are also called manganese nodules. They are metal-rich nodules found on the seabed of many of the Earth's oceans. Most are 5 to 10cm in diameter and are found at depths of 4000 to 5000m. Their origins are not fully understood, but they may have been formed by chemical precipitation of metals around a small solid object such as the shell of marine organism. They contain about 30% manganese with smaller amounts of iron, nickel, copper, cobalt, and titanium.
• What is open-cast mining?

  Larger machinery in open-cast mines allows overburden and minerals to be extracted more quickly and cost-effectively.
• What is deep-mining?


  Using machines allows mining underground where it may be too hot or dangerous for people, for example, deep gold and platinum mines in South Africa, at depth up to 3.8km. 
• What is polymer absorption?

  Metal ions dissolved in seawater will absorb onto the surface of some polymers and can be collected later. Synthetic polymers can be used, as can natural polymers such as lignin from wood and chitin from shrimp shells discarded by the fishing and aquaculture industries. This method is being developed to extract uranium and may provide a low-energy method of producing fuel for the nuclear power industry. 

   
• What are seismic surveys?

  These use sound waves produced at the surface that reflect off underground geological structures to determine the depth and shape of the rock structures. The reflected sound waves are detected by geophones at the surface. 
• What is trial drilling?

  Trial pits area type of intrusive site investigation used to determine the ground conditions across a site to study or sample the structure and composition of the subsurface. The most expensive technique pre sampling site.
• What are the environmental impacts of mineral exploitation? 


  Land take, habitat loss, loss of amenity, dust, noise, turbid drainage water, soil disposal, and mine site restoration.