HYDROMETALLURGICAL BENEFICIATION OF OIL SHALE IN AKTAU DEPOSIT

Hydrometallurgical methods are aimed at leaching by extracting valuable components into a sulfuric acid solution, as well as selective extraction on ion-exchange resins by sorption and precipitation of valuable components such as vanadium oxide, molybdenum oxide and uranium oxide. The presented methods are not implemented on an industrial scale, since there is no oil shale processing in the Republic. The perspective scheme of oil shale ash processing at the deposit is analyzed. It involves the addition of sodium chloride in the oxidative roasting process, the resulting ash is leached in vats of sulfuric acid 160 g/l, at room temperature, T:W=1:5, duration 60 minutes. The resulting metal-bearing sulfuric acid solution is filtered and sent to sorption, as well as to precipitation. The extraction of metals into the solution is, %: vanadium - 84.3 - 85.6, molybdenum -95.4 - 88.1 and uranium - 60.3 - 64.9, respectively. To extract metals from the productive solutions of leaching of oil shale ash from the Aktau and Sangruntau deposits, the following ion-exchange resins of the English company PUROLITE were used: for vanadium grade A-109, extraction was 79–81%, for molybdenum, grade A-100, recovery was more than 84–86% and uranium grade A-560 extraction 81 - 79%.