Behavior of Ni and Co in mining waste (overburden) of poor laterite ore from Kremze deposit in the magnetic field

This work presents new results of the pre-processing study of the Ni and Co-poor lateritic raw material from the reserved deposit Křemže in South Bohemia. The proposed technological treatment of the raw material aims to obtaining a concentrate of elements of interest. This step is missing in the present Ni and Co extraction from laterites as the entire amount of the mined rock is being leached. This work focuses on a possible pre-concentrating of elements of interest and facilitating the final metallurgical processes. We carried out experiments involving interconnected pre-processing modes, such as magnetic separation, heating of the raw material, oxidation by ozone, or use of a low frequency supersound. The experiments showed that an appropriate combination of these pre-processing modes can result in a substantial concentration of Ni and Co (from 0.4 to 1.05 wt. % Ni and 0.01 to 0.027 wt. % Co). The incorporation of these pre-processing modes into the technological method of laterite ore processing can reduce total costs of the raw mineral treatment. In addition, it makes it possible to process poorer raw materials whose treatment was previously uneconomic.