The conditions for the extraction of gallium, vanadium and nickel from the ash residues resulting at the burning of high-sulfur chemicals by sintering with soda and leaching with water have been examined. A new technology has been developed, characterized by higher extraction of gallium, vanadium and nickel, which is environmentally friendly for extracting Ga, V and Ni from the ash residue of heavy oil. In order to completely extract Ga, V and Ni from the ash residue, its thermal oxidation with alkaline (Na₂CO₃) additives was previously carried out. Installed the optimal conditions of the process. The results showed that the degree of leaching of vanadium and gallium was 98.8 and 97.5%, respectively, in the experimental conditions the sintering temperature was 800⁰ C, the sintering time was 1.5 hours, the optimum amount of soda needed for sintering was 1:1 by weight, the leaching temperature was 90–95⁰C, the ratio of the liquid-solid phase was (5–10):1 and the leaching time was 2 hours. After the recovery of Ga and V, the residue was followed leaching with a sulfuric acid solution to recover nickel

doi.org/10.32737/0005-2531-2020-1-46-52