Avaliação da influência de íons metálicos sobre o potencial de evolução do hidrogênio utilizando soluções recicladas de baterias automotivas.

Abstract

The growth in the production of automotive batteries in recent years has reflected in the process of acquiring raw materials, as well as in the reuse process of discarded batteries. Increasingly, companies in the industry and research centers are investing in the study of the recycling process of lead-acid battery components. Recycling of lead is already well known worldwide, however, for the recycling of the electrolytic solution (aqueous solution of sulfuric acid - H2SO4) we have little research and the recycling process has not yet proven economically viable. The battery industries MOURA S.A., through its research center, has been developing studies on the recycling process of the electrolytic solution to reuse these solutions in its process of producing new batteries. This study aimed to analyze the influence of metal ions present in the electrolytic solution at the end of the cycle of a lead-acid battery on the evolution potential of hydrogen gas (H2), with the perspective of determining parameters of these ions in the recycled solution. The methodology was based on the use of electrochemical techniques such as linear polarization, Tafel curves, chronopotentiometry and cyclic voltammetry. After the individual study of each contaminant and the application of the experimental planning of the mixture it was possible to develop the synergic study for a group of ions present in the electrolytic solution and verify the results demonstrated that it is possible to use the methodology and to evaluate the influence of contaminant ions on the potential evolution of hydrogen gas. The ions that demonstrated to have greater influence in the concentrations used in the experiments were copper, iron and manganese. We can conclude that the application of this methodology created in this research and with the advancement in the study of other factors that may be associated to the use of the recycled electrolytic solution will be possible to make this process economically feasible.