Development of the iron focused laterite

Global nickel production has seen an exponential increase since the late 1800s, predominantly sourced from sulphide reserves; however, lateritic deposits, which constitute approximately 70% of total nickel reserves, pose significant extraction challenges due to their composition. This research aims to develop the iron-focused laterite (ARFe) process to enhance nickel recovery from low-grade limonitic ores, typically characterized by less than 2% nickel content and complex mineral assemblages. A methodological approach was adopted, incorporating both SO₂ and H₂SO₄ into an integrated continuous circuit to optimize the extraction process and decouple acid supply from oxidation reactions. Results indicate a strong correlation between nickel and iron extractions, with a linear model revealing an R² value of 93%, underscoring the interconnectedness of these metals within the mineral matrix. Further analysis demonstrated the feasibility of co-crystallizing nickel and other divalent metals with FeSO₄·7H₂O during purification, suggesting a kinetic mechanism of incorporation rather than thermodynamic. The findings not only offer insights into enhancing nickel recovery rates, which have been conventionally capped at around 80%, but also contribute to the growing body of knowledge necessary for sustainable mining practices in the context of increasing demand for base metals.