Sulfuric acid leaching of metals from waste Li-ion batteries without using reducing agent

Author(s)

Guimaraes, L. F. ; Botelho Junior, A. B. ; Espinosa, D. C. R.

• Document type: Journal article
• Source: MINERALS ENGINEERING; v. 183, p. 14-pg., 2022-06-15.

Abstract

One way to obtain critical metals in lithium-ion batteries (LIBs) used in electric cars is to apply hydrometallurgical methods such as acid leaching. Current leaching technologies use reducing agents for cobalt extraction. However, thermodynamics indicates it is not required. In this study, cylindrical NMC 811 batteries (LiNi0.8Mn0.1Co0.1O2 as the active material of the battery's cathode) were ground in a knife mill, sieved, and leached without a reducing agent. A second ground was carried out in a Willey type mill and further sieved to obtain a material concentrated in active materials of the batteries' electrodes (cathode and anode). The leaching agent used for the experiments was sulfuric acid. Parameters such as acid concentration (0.5 mol/L, 0.75 mol/L, 1.0 mol/L and 2.0 mol/L), solid/liquid ratio (1:3, 1:5, 1:10 and 1:25), temperature (25, 50, 75 and 90 C), and time (up to 6 h) were studied. The optimal parameters were a concentration of 1.0 mol/L, a solid/liquid ratio of 1:10, and 90 C (for an isolated temperature experiment). However, in a leaching experiment varying the time parameter at a temperature of 50 C, the extraction of nickel, cobalt, and manganese achieved 90% in 1 h, making it a viable choice instead of the optimal temperature of 90 C found in the experiment isolated from the temperature parameter. (AU)

• FAPESP's process: 20/00493-0 - Sustainable mining: recovery of critical raw materials from batteries using environmentally friendly technologies
• Grantee: Jorge Alberto Soares Tenório
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/11866-5 - Development of innovative processes for the recovery of critical metals
• Grantee: Denise Crocce Romano Espinosa
• Support Opportunities: Research Projects - Thematic Grants