Abstract
Intensive mining and mineral processing in Kazakhstan have led to the accumulation of over 25 billion tons of industrial waste, including spent catalysts from the oil refining industry. These man-made raw materials often contain valuable metals, such as vanadium, molybdenum, and nickel, which are present in concentrations comparable to or higher than those in natural ores. The industrial exploitation of these resources is critical due to the depletion of high-quality raw materials and the environmental impact of waste accumulation. This research focuses on developing effective technologies for processing spent catalysts, which are rich in vanadium, molybdenum, nickel, and aluminum. The study investigates the physicochemical properties of spent catalysts and the effectiveness of various reagents in extracting valuable components. After carbonate and alkaline leaching of the feedstock, a concentrate with a nickel content of 10.09% was obtained. Nickel extraction from the concentrate was optimized using a reagent mixture of hydrochloric acid, chlorine compounds, and ammonium bifluoride, achieving an 85% extraction efficiency. Based on the results, a conceptual technological scheme for the processing of spent catalysts has been proposed, offering a promising solution for utilizing man-made raw materials in Kazakhstan's oil refining industry.