Extraction of vanadium and associated elements from black shale ores by hydrodynamic activation technology of sulfuric acid solutions

Abstract

The purpose of the work was to justify the possibility of converting vanadium in ore mainly into a readily soluble form in the form of hydrated oxides — vanadyls of the general formula VO2+ X (X is an anion) due to the hydrodynamic activation of sulfuric acid solution. Leaching tests were carried out in several stages and by various methods, the duration of which depended on the final indicators of vanadium extraction into the productive solution and its residual content in ore, as well as side components (Mo, W, rare earth metals). The article for the first time is examined the extraction of vanadium and associated elements from black shale ores (Kurumsak deposits, Kyzylorda oblast, the Republic of Kazakhstan) by the hydrodynamic activation of sulfuric acid. The activation of sulfuric acid solutions is carried out in the cavitation mode in a circulating type hydrodynamic apparatus at a pressure of 5 atm supplying a fluid flow to the cavitation nozzle by means of a centrifugal pump. It was found that the hydrodynamic activation of sulfuric acid leads to a significant increase in the degree of extraction of vanadium from 6 to 87% and related components depending on the decreasing in granule size. The technological parameters of leaching, such as pH, redox potential, salinity, acid intensity and filtration, are significantly improved. The results of chemical analysis of productive leaching solutions of the ore for the total contents of V2O5, uranium and rare earth concentrates were equal to 0.62 and 0.95 g/l, 47.26 and 41.43 mg/l and 62.44 and 37.26 mg/l irrespectively, that indicate the technological possibility of carrying out the heap leaching process.