Future Mineral Supplies

• Better remote sensing image resolution is an improvement in exploration. Newer satellites may carry improved sensors which generate a greater number of image pixels; multispectral sensors detect a greater range of wavelengths of visible and infrared light, providing more detailed information on the mineral composition on Earth.
• Portable field equipment is an improvement in exploration. Lab equipment has become smaller and more portable as electric components become lighter, more powerful batteries have developed and energy consumption has been reduced. This saves time as results are available immediately. It is available in IR spectroscopy, X-Ray fluorescence and radiation detection.
• Deep mining in mechanisation is an improvement of exploitation. This is because using machines allows mining underground where it is too hot or dangerous for people. For example, deep gold and platinum mines in South Africa.
• Open-cast mining in mechanisation is an improvement of exploitation. This is because larger machinery allows overburdens and minerals to be extracted quicker and be more cost-effective. Excavators can weigh 13,000T, and trucks can carry up to 300T. This size machinery has allowed deeper open cast mines to be developed, allowing more valuable minerals to be exploited.
• Bioleaching is used for the exploitation of low grade deposits and is an improvement of exploitation. Bioleaching is the use of living organisms to extract metals from their ores. For example, Aspergillus fungi can be grown on scrap electronic components, which produce acids that dissolve metals such as nickel, lead, copper and tin. The metals in solution from bioleaching can be separated by electrolysis.
• Phytomining is used for exploitation of low grade deposits and is an improvement of exploitation. Phytomining is using certain plants that can absorb metal ions from soil or water and concentrate them in their leaves. The plants are planted at polluted sites or as commerical extraction of metals. They are then harvested and incinerated, and the metals in the ash can be dissolved using acids, then separated by electrolysis.
• Iron displacement is used for exploitation of low grade deposits and is an improvement of exploitation. Iron is a reactive metal, and will displace copper ions from a solution - the solid iron goes into a solution as the copper ions are deposited as solid copper metal, which can be collected.
• Leachate collection is used for exploitation of low grade deposits and is an improvement of exploitation. Rainwater that percolates through spoil heaps dissolves soluble metal ions. The drainage leachate can be recirculated through the spoil heaps to increase the concentration of metal ions in solution. When the concentration is high enough, the metals can be extracted through electrolysis.
• Waste that can be used for recycling can come from two sources:

  1. pre-consumer wastes - e.g waste trimmings produced by cutting or stamping machines
  2. post-consumer wastes - e.g discarded consumer products
• Most materials in domestic waste can be recycled if they are separated by the public before collection, as this prevents reduction in quality caused by mixing wastes.
• Industry can use recycled elements - however, this is costly and complex.
• One problem with recycling schemes is transport. Extraction of ores involves bulk resources where bulk transport can be used creating major economies of scale and lower unit cost. Recycling may involve the collection and transport of smaller quantities which is more expensive and bulk transport is impossible.
• One problem with recycling schemes is labour costs. Processing smaller quantities of materials increases labour costs, but recycling doesn't require the level of skills or training that extraction requires, so technically they will be lower.
• One problem with recycling schemes is separation. Alloys of mixed metals can't be easily separated. For example, recycled aluminium alloys can't be used where pure aluminium is needed.
• One problem with recycling schemes is identification. Identification is labour intensive and slow to identify the composition of recycled materials where the composition is important for reuse.
• One problem with recycling schemes is energy costs. Recycling materials saves the energy needed for extraction, however this saving may be exceeded by the energy used for transport if small quantities are collected.
• One problem with recycling schemes is public cooperation. Successful post-consumer recycling schemes require public cooperation to separate wastes.
• One problem with recycling schemes are waste losses as not all used materials can be recycled. Some are unavoidably lost where litter is discarded or placed in general waste for landfill.
• Polymetallic nodules (manganese nodules) are metal-rich nodules found on the seabed of Earth's oceans. They are 5-10cm in diameter and found at depths of 4000-5000m. It is believed they are formed by the chemical precipitation of metals around small objects, such as the shells of marine organisms. These nodules contain around 30% manganese, with smaller amounts of iron, nickel, copper, cobalt and titanium.
• The problems with collecting polymetallic nodules are that: large scale exploitation will be expensive and will require international agreements on the ownership of the seabeds and their resources; recovering the nodules will disturb the seabed and kill benthic organisms that live there. It will also increase the turbidity of the water by disturbing the seabed, and re-deposition of disturbed sediments is likely to kill filter feeders, whilst also covering and killing benthic organisms.