Exploring Sustainable Pb Recovery from Zinc Plant Residues via Hydrometallurgical Processes: Comparative Analysis of Zinc and Aluminum Powder Cementation

Abstract

This study explores the recovery and preparation of Pb from Zn plant residues (ZPR), specifically leaching filter cake (LFC), through a hydrometallurgical process that includes the cementation of Pb using Zn and Al powder. The process consists of three key stages: acidic washing of zinc, alkali leaching, and the subsequent cementation of lead using zinc and aluminum powder. The effects of various parameters such as powder amount, temperature, reaction time, and stirring speed on the reaction kinetics were systematically examined. Optimal separation conditions were determined for both zinc and aluminum powder, with Pb cementation achieving 97.56% and 99.95% respectively, under specific conditions. Additionally, a kinetic study was conducted to evaluate the reaction mechanisms and activation energies associated with Pb cementation using zinc and aluminum powder. The results indicated that Pb cementation was powder-controlled in both cases, with reaction activation energies of 8.6 kJ/mol and 4.6 kJ/mol using zinc and aluminum powder, respectively. Furthermore, the use of aluminum powder demonstrated several advantages including enhanced performance, high purity of Pb product, and reduced powder consumption. This research advances the optimization and understanding of Pb recovery processes from ZPR, emphasizing the potential of aluminum powder as a promising alternative for effective lead cementation.