Metals: economic geology metal extraction

Economic geology is the study of the origin and distribution of mineral deposits of metals, other useful materials (such as building stone and salt), and fossil fuels (petroleum, natural gas, and coal). The economic geologist explores for these materials, predicts the mineral reserves of known deposits, and assesses the economics for the extraction of the ore. For instance, for an iron ore deposit, the geologist needs to assess the kinds and amount of iron minerals present, the depth of the deposit, the location of the deposit, and the ownership of the land so that estimates for the possibility of mining the iron ore profitably may be made. 

Current estimates of the available reserves and further resources of uranium and thorium, and their global distribution, are shown in Figs. 5.44-5.50. The uraruum proven reserves indicated in Fig. 5.44 can be extracted at costs below 130 US /t, as can the probable additional reserves indicated in Fig. 5.45. Figure 5.46 shows new and unconventional resources that may later become reserves. They are inferred on the basis of geological modelling or other indirect information (OECD and IAEA, 1993 World Energy Council, 1995). The thorium resource estimates are from the US Geological Survey (Hedrick, 1998) and are similarly divided into reserves (Eig. 5.47), additional reserves (Fig. 5.48) and more speculative resources (Fig. 5.49). The thorium situation is less well explored than that of uranium the reserves cannot be said to be "economical", as they are presently mined for other purposes (rare earth metals), and thorium is only a byproduct with currently very limited areas of use. The "speculative" Th-resources may well have a similar status to some of the additional U-reserves. 

Mining is the process by which ores or related materials are extracted from the Earth. Ore is defined as a rock or mineral, generally metallic, which can be mined, processed, transported, and sold at a profit. Therefore, the classification of an Earth material as ore depends as much on economics and technology as geology. Non-metallic substances that are commonly mined but not considered to be ores include coal, phosphate, and sand and gravel. The term groundwater mining is sometimes... 

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