Assessment of the prospects for processing oxidized nickel ores using microwave energy

The Ural region holds an estimated 1.5 million tons of nickel reserves, located in the industrially developed Chelyabinsk, Sverdlovsk, and Orenburg regions. At present, however, these deposits are not being exploited, and metallic nickel is not produced in the Urals, as metallurgical facilities have been completely shut down. The reserves are represented by oxidized nickel ores (ONO) – a complex raw material with low nickel and cobalt contents, whose processing by existing technologies is economically unfeasible. The challenge is compounded by the absence of a beneficiation method for ONO that yields a concentrate; therefore, all current technologies require processing the entire ore mass, which results in high reagent consumption and substantial energy costs. Research is ongoing to develop new technological approaches, including alternative methods for extracting nickel and cobalt from ONO in the Ural deposits. One promising option is the use of microwave (MW) energy to unlock nickel-bearing minerals and accelerate the dissolution of nickel and cobalt. This study evaluates the effect of microwave energy on nickel recovery from oxidized nickel ores of the Ural region. Comparative data are presented for conventional sulfuric acid leaching and for the process with microwave energy applied. A series of test studies was carried out to assess the feasibility of using microwave energy for ONO processing. The comparison of technological parameters demonstrated the advantage of atmospheric sulfuric acid leaching with microwave energy, which achieved nickel recovery of up to 95 % in a relatively short time. These results identify this approach as the most promising for practical implementation.