Prospects of the Hydrometallurgical Processing of Laterite Nickel Ores with Selective Nickel and Cobalt Recovery

The hydrometallurgical processing of preliminarily reduced ferriferrous laterite (limonite) ores from the Buruktal deposit using weak solutions of sulfuric acid under atmospheric pressure with nickel and cobalt recovery to the solution is studied. The introduction of an ammonia reagent (NH₄)₂SO₄, which forms complexes with Ni and Co, into the initial solution is shown to enhance the selectivity of the process. Sulfuric acid leaching at 90°C and pH 3.0 and 3.5 in the presence of 5% (NH₄)₂SO₄ for 2 h shows high recovery parameters: more than 90% for nickel and up to 70% for cobalt. The process is characterized by a decrease in the H₂SO₄ consumption by four times compared to the known method of the sulfuric acid pressure leaching of ferriferrous oxidized nickel ores.