Work

Integrated acid leaching of spent battery cathode material (LCO, NMC111) and flotation tailings of pyrite and pyrrhotite

Year: 2025

Type: article

Abstract: Lithium-ion batteries require number of metals which have been listed as critical raw materials in European Union due to their supply risk and economic importance. Therefore, more emphasis needs to be put on (i) recycling of spent batteries, (ii) utilizing other secondary sources of battery metals and primary mining waste. In this research, leaching of battery metals from cathode materials—lithium cobalt oxide (LCO) and lithium nickel manganese cobalt oxide (NMC111)—was investigated with the aim to use waste fraction of primary mining, namely sulfide-rich flotation tailings, as reductant. Two types of tailings were investigated in the current study: pyrrhotite-pyrite tailings and pyrite tailings. These tailings contain reductive power necessary for leaching, as well as battery metals incorporated in the sulfide matrix. The investigated parameters were temperature (40–80 °C) and mass ratio of cathode material and tailings (0.5–2 g/g) whereas S/L-ratio (100 g/L), acid concentration ([H 2 SO 4 ] = 1 M), and leaching time (180 min) were kept constant. The results showed that both pyrrhotite-pyrite as well as pyrite dominated tailings can act as an effective reductant for the leaching of metals from cathode materials. The extraction efficiency of battery metals correlate with dissolved iron concentration. When only pyrite tailings were used in the process, the reductive effect of S 2 2− could also be recognized as lower concentration of dissolved Fe 2+ was required when compared to use of pyrrhotite tailings. At 80 °C, LCO and NMC could be completely dissolved within 60min while simultaneous extraction of battery metals from sulfide flotation tailings was up to 17 % of Ni, 15 % of Co, and 27 % of Cu.

Source: Hydrometallurgy

DOI: 10.1016/j.hydromet.2025.106618

Authors: Anssi Karppinen, Henna Liljanko, Sipi Seisko, Mari Lundström

Institution: Aalto University

Language: English

Topic: Extraction and Separation Processes

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,350