Ferronickel Production from Nickel Laterite via Sulfide Chemistry

Abstract

Nickel and ferronickel are critical components for production of products ranging from commodity metals to lithium-ion batteries. Current and future production rely on processing lateritic sources of nickel, which exhibit a range of technical and sustainability challenges. New sulfide-based process chemistries have been developed as platform technologies to decarbonize mining, materials separations, impurity management, and metals production. Herein, we utilize sulfide chemistry to produce carbon-free ferronickel. We first demonstrate selective sulfidation of mixed laterite feedstocks to form an iron-nickel sulfide matte. We then explore the thermodynamics of vacuum thermal treatment processes to enrich the matte in nickel via selective oxidation of iron. Finally, we employ aluminothermic reduction via reactive vacuum distillation to produce ferronickel from iron-nickel sulfide. These results lay the groundwork for an autothermal pathway to manufacture ferronickel from lateritic ore without direct greenhouse gas emissions.