Processo de recuperação de lítio e cobalto de baterias de íons de lítio por lixiviação empregando biolixiviação e ultrassom

Abstract

Lithium-ion batteries (LIBs) are energy storage devices used in electronic equipment and with the constant innovation of these devices, there is an increase in the generation of discarded waste. The lack of management in the disposal of these batteries can cause environmental and public health disorders. Recycling appears in this scenario to promote the closure of the production cycle. However, recovery methodologies need to be based on less polluting processes. The motivation of this study was to evaluate the recovery of metals from lithium (Li) batteries, through the study of the effect of sonication in the leaching process using a medium composed of a mixture of sulfuric acid (1.25 M) with an effluent medium of fermentation by consortium microbial, rich in organic acids (0.75M). The potential of Penicillium. oxalicum and the anaerobic microbial consortium in bioleaching processes for the recovery of Li and Co was also investigated. The samples used were electrodes extracted from lithium-ion batteries, which had previously gone through discharge, dismantling, grinding, sieving and physical-chemical characterization processes. In addition to bioleaching, adaptation tests were conducted with the fungus Penicillium oxalicum and the anaerobic microbial consortium at increasing doses of samples from the LIBs electrodes. The carbon source used in the bioleaching tests was lactose from powdered whey permeate (WIP), which is a by-product resulting from the production of cheese and other dairy products. The analyzes used to monitor the experiments were measurements of the hydrogen ion potential (pH), cell concentration by gravimetry and initial cell count in a Neubauer chamber (for the fungus), sugar concentration by DNS and metal content by absorption spectroscopy (EAAC), X-Ray Fluorescence (FRX) and Scanning Electron Microscopy (SEM). Bioleaching with P. oxalicum promoted a recovery percentage of up to 73.7% of lithium and in bioleaching with microbial consortium of up to 77.6% of lithium. In the adaptation test with P. oxalicum the maximum recovery was 63.3% for Li and 54.3% for Co. In adaptation with the microbial consortium, the percentage of maximum lithium recovery was 98.0%. The results showed that the study of these microorganisms in bioleaching was promising. With regard to leaching under sonication, the experiments carried out in the time intervals (1 h to 5 h) and temperature (60 ºC and 80 ºC), indicate that considerably higher times should be tested.