Themo-Kinetics of leach leaching from recycled batteries

Abstract

An approach to recycle lead from spent lead-acid batteries by using citric acid and EDTA has been studied in this paper. This novel method would provide an alternative way to treat the Colombian national resources and contribute to the mitigation of the environmental impact generated by Pyrometallurgical processes currently implemented in the lead acid battery recycling industry. The methodology followed to achieve the project objective was the following: selection and preparation of the material coming from recycled batteries; characterization of the material to be leached; Thermodynamic analysis of the possible reagents or leaching agents and finally a stage of leaching of the material from the lead batteries. The results indicate that the solid material of batteries of lead-acid, is constituted in its great majority by PbSO₄ and PbO₂. With the thermodynamic stability analysis of the formed lead complexes it is determined that the conjugate base of the citric and ethylenediaminetetraacetic acids (EDTA) form stable lead complexes in the water stability region. In the leaching tests, lead extractions of 77% were achieved with the citrate ion and 99% with the EDTA ion.