CICERO · MSA-based circular hydrometallurgy for sustainable, cost-effective production of NMC cathode materials

On 16 March 2023 the EC published the Critical Raw Materials Act (CRMA) proposal that sets “benchmarks along the strategic raw materials value chain and for the diversification of the EU supplies”. By targeting the domestic refining of three “strategic” battery-related CRMs, i.e., Ni, Co and Mn, the CICERO project addresses the second CRMA benchmark: i.e., > 40% domestic processing/refining. To tackle the twin problems of (1) Europe’s dependence on a few third countries (i.e., DRC, Indonesia, China) for the supply of Ni, Co and Mn for our NMC Li-ion battery production, and (2) the fact that these metals are currently produced at a huge cost in terms of environment, health and safety, CICERO puts in place a sustainable, cost-effective refining model for Ni, Co and Mn, and the downstream conversion into “made-in-Europe” NMC cathodes. The CICERO project is the first ever to develop a circular hydrometallurgical Ni, Co & Mn processing/refining scheme that uses methanesulphonic acid (MSA) – a commercial, green, REACH-compliant & affordable acid – rather than H2SO4. CICERO recovers, refines and converts Ni, Co and Mn from domestically available secondary raw materials: (a) post-mining raw materials (sulphide & laterite tailings) and (b) Ni/Co/Mn-bearing intermediates incl. MSP, FeNi, Ni-matte and Mn-anode sludge. To achieve this, CICERO develops a suite of novel metallurgical unit processes for advanced MSA leaching and solution purification, the conversion to battery-grade MSA salts, and the synthesis of NMC cathodes in MSA media, with sound reagent regeneration & iron recovery in line with the Twelve Principles of Circular Hydrometallurgy. This research is supported by advanced thermodynamic & kinetic modelling for solid-liquid & liquid-liquid equilibria relevant for Ni/Co/Mn processing/refining in MSA media. CICERO introduces a new paradigm for metallurgical processing/refining and increases society’s acceptance of, and trust in, sustainable CRM production in Europe.