Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Application of computational thermodynamics tool in the simulation of pyrometallurgical operations of lead-acid battery recycling
Submission Author:
Leonardo Henrique Gomes , PR
Co-Authors:
Leonardo Henrique Gomes, Maria José Jerônimo de Santana Ponte, Haroldo Ponte, Wagner Viana Bielefeldt, Elan Forteski, Rodrigo Helleis, Fabricio Torres Borghi
Presenter: Leonardo Henrique Gomes
doi://10.26678/ABCM.COBEM2023.COB2023-1950
Abstract
This work, carried out with the application of computational thermodynamics, deals with the fundamentals of lead production through the recycling of lead-acid batteries. The objective of this work was to evaluate the understanding of the thermodynamic balances of the steps that are established during the process, to contribute to the improvement of operational control and recovery of Pb, which is the main element to be recovered. The research methodology carried out at the Department of Mechanical Engineering of the Federal University of Paraná (UFPR) and the Department of Metallurgy of the Federal University of Rio Grande do Sul (UFRGS), focused on using the FactSage software version 7.0, which consists of a series of FactPS, FToxid, FTsalt and FTmisc modules, with their respective databases. To address the equilibrium steps of a system, we used the thermodynamic equilibrium module that was based on the minimization of the Gibbs Energy, which once specified, the atomic species of a system "react" until reaching a state of chemical equilibrium. The software in this case determines which phases are present in the equilibrium state and calculates the concentration of the constituents in the respective phases. The diagrams are calculated in the module 'Phase Diagram' from information and parameters entered (partial pressure and temperature) and the limits of the phases are marked automatically, and you can add tie-lines manually. Analyzing specifically the case of lead (Pb) and its recovery process from lead-acid batteries, it is possible to conclude that it presents intrinsic difficulties, because the process takes place by batch in rotary furnaces. Therefore, (i) one cannot associate a certain step of the process with a certain location of the reactor, as would be for example, the case of a continuous reactor such as the blast furnace, where chemical reactions take place at known points in the furnace, and (ii) time is also a variable. Even so, there are regions where certain steps can be located, such as the oxidation of sulfides at the top of the charge and the reduction of oxides at the bottom. Thus, the diagrams presented and discussed based on the reviews found in the literature represent and validate the pyrometallurgical process with their respective areas of predominance, especially in the ustulation stage and in the lead/matte separation step, presenting the effect of the addition of iron (Fe) to the system, reducing the Pb content in the final residue, showing the importance of simulating and analyzing the process thermodynamically and also from the environmental point of view.
Keywords
Termodinâmica Computacional, Equilíbrio Termodinâmico, Processo Pirometalúrgico, Meio Ambiente
