Processing Black Mass into a Mixed Nickel/Cobalt Hydroxide Precipitate and Industrial-Grade Lithium Carbonate: A Techno-Economic Analysis Perspective

The lithium-ion battery (LIB) uptake is accelerating rapidly as part of the global push toward energy decarbonization, particularly in the automotive sector. Increased demand is expected to put a significant pressure on the mining industry to supply critical energy metals (e.g. Li, Ni, Co). In this regard, the rapid development and deployment of efficient processes for LIB recycling as part of a circular economy is of great practical importance for alleviating raw materials supply issues as well as reducing the environmental footprint associated with mining, manufacturing, and end of life. The development of effective LIB recycling practices presents unique obstacles such as the complexity of both individual LIB cells and packs, the diversity of cathode chemistries in use and under development, and the lack of standardization between battery manufacturers. Additionally, effective comparison between proposed processing flowsheets can be complicated by a lack of value quantification and life cycle impact parameters, especially at early stages of development. The following work presents a conceptual recycling flowsheet for the processing of black mass (BM) obtained from a mixed LIB feed stream into a mixed hydroxide precipitate (MHP) and industrial-grade lithium carbonate. The intent of this exercise is to introduce an industrially proven and robust “Base Case” hydrometallurgical processing route which recovers nickel, cobalt, and lithium in forms which are readily integrated into existing material value chains. A Techno-Economic Analysis (TEA) was performed, consistent with the level of AACE Class 5 capital and operating cost estimation. Results of this study can provide a basis for benchmarking alternative LIB recycling strategies. The TEA is based on a hydrometallurgical process plant with an annual capacity of 16,560 dry tonnes of BM, which corresponds to a nominal throughput of 2 dry tonnes of BM per hour. In this study, BM composition is taken to be 5.1 wt.% Co, 23 wt.% Ni, and 4.0 wt.% Li. The plan is estimated to produce 8440 dry tpa of MHP product containing 44 wt.% Ni and 9.4 wt.% Co, and 3150 dry tpa of industrial-grade lithium carbonate. The estimated CAPEX and OPEX are 44 MUSD and 32.9 MUSD / year, respectively. The calculated payback and Net Present Value after 20 years (NPV20) are 1.6 years and 220 MUSD, respectively.