Some Features of the Sulfuric Acid Leaching of the Reduced Ferriferous Oxidized Nickel Ore

The oxidized nickel ores from the Buruktal deposit (Orenburg oblast) contain significant sources of nickel (1 377 000 t). However, these ores are fairly poor in nickel (0.8–1.0%) and cobalt (0.04–0.07%) as compared to foreign deposits. The results of studying the possibility of nickel recovery by hydrometallurgical processing of ferriferous oxidized nickel (limonite) ore with weak solutions of sulfuric acid are presented. The studies are carried out for prereduced limonite ore. As a result of reduction, entire nickel and partially iron present in the initial ore are reduced to the metallic state to form an NiFe alloy. The influence of various factors on the degree of recovery of nickel into a solution and the acid consumption is studied.