A Novel Method for Extracting Crude Pb from Lead-Acid Battery Grid Alloy By Vacuum Distillation

Abstract

The waste lead-acid battery grid, a predominantly lead-based alloy, has seen a significant surge in production, positioning it as a primary source of Pb. Conventionally, pyrometallurgical techniques employed to treat this waste are fraught with the complex process of segregating Sb and As to extract Pb. This not only escalates energy consumption but also exacerbates environmental challenges with the emission of hazardous wastes. As an alternative, this research introduces vacuum distillation (VD) as a novel and efficient technique for the elimination of Sb and As from grid alloy. Through a blend of theoretical and experimental examinations, the feasibility of utilizing VD for direct crude Pb synthesis was corroborated. Empirical results demonstrated that a remarkable 98.97% Pb from the grid alloy underwent recovery, producing crude Pb with a purity level of 98.56% at a distillation temperature of 923 K sustained for 60 min. This extracted crude Pb is apt for subsequent refinement through electrolytic processes. Sb and As elements transitioned to volatile phases, avoiding the generation of arsenic-containing dust. A salient feature of this VD technique is its zero emissions, both in gaseous and aqueous forms, ensuring an eco-friendly and sustainable extraction of crude Pb.

Keywords: Waste lead-acid battery, Grid alloy, Vacuum distillation, Crude Pb, Sustainable purification