Abstract
The rising demand for nickel and cobalt in battery materials and high-performance alloys has renewed interest in lateritic ores, yet Kazakhstan’s substantial resources remain underused due to the lack of effective extraction technologies. This study provides the first comprehensive mineralogical and processing evaluation of laterite ore from the Kempirsay deposit and demonstrates the applicability of the sulfation roasting-water leaching (SR-WL) method to Kazakh high-iron laterites. Physicochemical analysis showed that Ni and Co are mainly hosted in Fe-bearing phases goethite, hematite, and trevorite with minor incorporation in silicates; the ore contains, (in wt.%):1.08 Ni, 0.104 Co, and 20.2 Fe. Roasting at 500 °C with 30 wt.% H2SO4 generated readily leachable sulfates, and subsequent leaching at 85 °C (180 min, S: L = 1:6) extracted 93.3% Ni, 92.0% Co, and 84% Fe. Selective dissolution was achieved by roasting at 700 °C with 50 wt.% H2SO4, yielding 90.08% Ni and 90.01% Co while limiting Fe dissolution to 6.12%, producing a low-iron pregnant leach solution (PLS) containing, g·L−1: 2.11 Ni, 0.35 Co, 2.12 Fe. Overall, the results show that the SR-WL process is a viable and newly validated pathway for converting low-grade Kazakh laterites into Ni-Co intermediates suitable for modern metallurgical supply chains.