Coal-type mining techniques

Scanning electron microscopy with an energy-dispersive x-ray system accessory has been used to identify the composition and nature of minerals in coals and to determine the associations of minerals with each other. Examinations can be made on samples resulting from ashing techniques or whole coal. With this technique it is possible to identify the elemental components and deduce the mineral types present in coal samples. Computerized systems to evaluate scanning electron microscopy images have been developed and are useful in characterizing the minerals in coal mine dusts and in coal. 

The lecoveiy of natural resources from the Earth s crust is an important activity, in which sintered hard metals play a cracial role. It relates to both underground and open cast mining techniques for the recoveiy of minerals - metallic and non-metallic - like carbon (coal), potash, natron, gypsum and of course petroleum drilhng (petroleum, natural gas). The methods of evacuation and the types of tools used depend on the type of stratification encountered. We can classify drilhng into three types ... 

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