The influence of density, temperature and time on acid leaching of lithium-ion battery cathodes for lithium and cobalt recovery from mobile phones

Resumen

Urban mining has gained prominence in recent years due to the drawbacks and high costs associated with sourcing raw materials for the production of electrical and electronic devices. Therefore, the efficient recovery of valuable metals is a challenge. This study aims to investigate the effect of density, temperature and time on the leaching process. Pure powdered cathode material was obtained by dismantling spent mobile phone batteries. A two-level factorial experimental design with a replication at the center was proposed to analyze the effect on the recovery of lithium (Li) and cobalt (Co). Nine sulphuric acid leaching experiments were carried out, varying the pulp density (64.5-196 g/L), temperature (50-100 ºC) and time (60-210 min). After processing the data in Statgraphics Centurion XVIII software, the highest recoveries for both metals were 64.5 g/L at 100 ºC for 60 minutes, resulting in recoveries of 76.16 % Li and 31.17 % Co. They therefore have a residue generation ratio per gram recovered of 91.2 g waste/g Li and 36.1 g waste/g Co. The analysis showed that the pulp density (ratio of powdered cathode material to water solution with sulphuric acid) and time had the most significant effect on the lithium recovery efficiency as their values decreased. On the other hand, cobalt recovery efficiency is influenced by temperature, with higher temperatures leading to better recovery rates.