URANIUM STOCKS
The worldwide production of uranium in 2006 amounted to 39 655 tonnes, of which 25% was mined in Canada. Other important uranium mining countries are Australia (19.1%), Kazakhstan (13.3%), Niger (8.7%), Russia (8.6%), and Namibia (7.8%).
Yellowcake is a concentrated mixture of uranium oxides that is further refined to extract pure uranium.
Uranium ore is mined in several ways: by open pit, underground, in-situ leaching, and borehole mining (see uranium mining).[4] Low-grade uranium ore mined in 2006 typically contains 0.01 to 0.25% uranium oxides. Extensive measures must be employed to extract the metal from its ore. High-grade ores found in Athabasca Basin deposits in Saskatchewan, Canada can contain up to 70% uranium oxides, and therefore must be diluted with rock prior to milling, in order to reduce radiation exposure to workers. Uranium ore is crushed and rendered into a fine powder and then leached with either an acid or alkali. The leachate is subjected to one of several sequences of precipitation, solvent extraction, and ion exchange. The resulting mixture, called yellowcake, contains at least 75% uranium oxides. Yellowcake is then calcined to remove impurities from the milling process prior to refining and conversion.
Commercial-grade uranium can be produced through the reduction of uranium halides with alkali or alkaline earth metals. Uranium metal can also be made through electrolysis of KU5 or UF4, dissolved in molten calcium chloride (CaCl2) and sodium chloride (NaCl) solution. Very pure uranium can be produced through the thermal decomposition of uranium halides on a hot filament. TO READ MORE....
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