Economic challenges of Fe, Co, Ni, Sc processing from complex ore deposits on the example of Sebuku Fe-(Ni)-Laterite (Indonesia)

Securing a predictable and affordable supply of critical metals for the high-tech industry, coupled with tightening supplies and augmented competition for available resources, leads to increasing exploration of complex and/or unconventional deposits. Complex ores often require extensive metallurgical processing and thus suffer from high capital and/or operational expenditures (CAPEX and OPEX). The Fe, Co, Ni, and Sc extraction from Sebuku Fe-(Ni)-Laterite was studied. The study compares conventional and alternative extraction methods, considering both the metal value of the deposit and the operational expenditures involved.

Conventional methods, such as roasting, stirred leaching, and pressure leaching, showed high extraction efficiencies for the target elements but also a significant demand in energy and chemicals. Alternative reducing agents in combination with conventional methods benefit faster leaching times and reduced energy demand at similar extraction efficiencies and might result in a more cost-effective and environmentally friendly process chain. Unconventional approaches, such as ionic liquids and deep eutectic solvents, report lower recovery rates necessitating further basic investigations to optimize the leaching agents and/or to develop efficient process designs with respect to the specific requirements.

Independent on the approach used, a basic process design including the implementation of potential recycling processes and waste/wastewater streams is mandatory for a first economic assessment of the individual routes. Based on this evaluation, the study highlights the need for further optimization to make beneficiation approaches feasible and attractive for potential investors especially viewing the current market prices for metals and chemicals.

This study is part of the StratOre Project (Client II).