Chlorination of uranium ore for extraction of uranium, thorium and radium and for pyrite removal

CIM Bulletin, Vol. 72, No. 808, 1979

J. M. SKEAFF, Research Scientist, CANMET, Energy, Mines and Resources Canada, Ottawa

Concern over the acid drainage and radionuclide dissolution problems associated with current uranium tailings disposal methods, as well as the lack of thorium production in Canada, has prompted investigation into new and improved methods for the extraction of uranium and thorium from their ores.One such method currently under investigation at CANMET is the high-temperature chlorination of uranium ore, for which the objective is to develop a process which is both economically viable and environmentally acceptable. Testwork has been directed toward obtaining high extractions of uranium, thorium and radium-226, as well as iron, sulphur and the rare earths, and consists of chlorinating samples of an Elliot Lake uranium ore at elevated temperatures and repulp-ing the resulting calcine in dilute HCl. The effect of temperature and chlorine throughput on the extraction of the various metals has been investigated. The best conditions yielded extractions of uranium, iron and sulphur (all as chlorides) greater than 95 per cent. Chlorine consumption varies between 6 and 16 per cent by weight of the ore charge.

Mots Clés: Extractive metallurgy, Ore processing, Chlorination, Ra-dionuclides, Pyrite, Tailings disposal, Uranium tailings, Acid drainage, Uranium extraction, Thorium extraction, Radium extraction, Elliot Lake.