mineral resources

Mineral Resources



Contents of Entire Course

Reserves vs. Resources
Factors involved in deciding whether to mine a potential ore body
The Rise of Recycling
Environmental Problems associated with various aspects of Mining

adapted to HTML from lecture notes of Prof. Stephen A. Nelson Tulane University


Reserves vs. Resources

Reserves - Are dependent on price.
Resources - Total amount of material present.



(Notice that the production of gold roughly followed the price of the gold. In 1980 the price of gold drastically went up and very shortly after that we see a sharp increase in gold production. This sharp increase reflects the addition of other gold sources that were previously thought too costly to use.)
Typically a gold mine may contain 10 grams (one-third of an ounce) of gold per ton of ore mined.

Factors involved in deciding whether to mine a potential ore body

  • Price of commodity
  • Size of ore body
  • Cost of capital investment
  • Underground vs. Surface Mining ( underground mining is much more expensive generally will only do this if there is a seam or if the ore can be sold at a high price)
  • Extent of mineral processing necessary (eg- 8 g of gold is recovered from 1 ton of rock)
  • Cost of mining
  • Cost of transportation
  • Cost of reclamation (returning land to previous pre-mining condition)
  • Is there a market?
  •  
    Mineral Reserves and Resources 
    Material  World Reserve 
    1,000 tons 
    World Lifetime
    Years 
    U.S. Reserves
    1,000 tons 
    U.S. 
    Bauxite  23,000,000  219  20,000  4.1 
    Chrome  1,400,000  109 
    Iron  150,000,000  178  16,100,000  244 
    Nickel  47,000  51  23  0.2 
    Platinum  56,000 tons  190  250 tons  2.2 
    Gold  44,000 tons  20  4,770 tons  47 
     
     


    The Rise of Recycling
     
    Notice how the consumption of metals has changed from a strictly primary source to a 50% primary source and 50% recycled source since about 1980.



    Another overhead has to do with what % of scrap metal for a variety of different metals were used instead of mining new reserves. The below is a list of the findings.
     

     
    Metal  % of scrap metal used 
    Al  40 
    Cu  42 
    Fe  55 
    Pb  70 
    Zn  30 
    Sn  30
     
     

    Environmental Problems associated with various aspects of Mining

  • Exploration - Need to put in roads, cut lines through woods, etc.
  • Mining
  • Underground - Not as bad, except that sometimes hazardous materials are removed.
  • Surface - Pit or strip mine. Can cover very large tracrts of land.
  • Processing
  • Waste materials need to be disposed of, and are often toxic.
  • Smokestack - Ejects toxic material into the atmosphere.

  • Sulfides are common - Arsenic, lead, mercury, sulfuric acid.

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