Study of leaching processes of sintered black shale ore

This paper presents the results of physical and chemical investigation of black shale ore, as well as the investigation of combination of hydro- and pyrometallurgical methods in the sintering process of black shale ore with ammonium hydrosulfate to convert metals into water-soluble form. The homogeneous composite of black shale ore taken for the study consists of 67 % SiO2, 18 % C and 3 % H2O, 0.683 % V, 0.0415 Mo, 0.0148 % U3O8 and other components. Thermogravimetric analysis of sintering of carbon-silica ore with ammonium hydrosulfate in the presence of sulfuric acid was performed in the temperature range 20-1000 °C. It is established that at low-temperature sintering of ore with hydrosulfate ammonium after further leaching with sulfuric acid solution the extraction of uranium, vanadium, molybdenum and rare earth metals is 98.2 %, 91.3 %, 82.2% and 78.3 % respectively. The optimal leaching temperature is 90 °C, the ratio S: L = 1:3, and the leaching time is 2 hours.