Herein, a novel direct leaching-electrowinning process has been proposed to recover lead from spent lead-acid battery paste. Calcium chloride was used as the leaching agent and iron sheet was used as a soluble anode.
Usually, spent lead-acid batteries are separated in lead recycling plants by dismantling and sorting into four fractions: lead paste, metallic fragments, waste acid, and plastic case ( Worrell and Reuter, 2014; Zhang et al., 2019 ). The processing of lead paste is relatively complex because it contains refractory lead sulphate.
The spent lead-acid battery is primarily composed of lead paste, waste acid electrolyte, lead alloy grid, polymer container and some other parts including connecting rods . Among them, the spent lead paste with complex compositions, mainly comprising PbSO 4, PbO 2, PbO and a small amount of lead metal, is the most difficult to deal with .
Among them, the spent lead paste with complex compositions, mainly comprising PbSO 4, PbO 2, PbO and a small amount of lead metal, is the most difficult to deal with . Currently, pyrometallurgical and hydrometallurgical processes have been introduced to recover metal Pb from the spent lead paste , , .
As an important contribution for the recycling economy, the process provides a viable alternative to recycle metal lead from spent lead paste in lead-acid battery with a convenient and environment-friendly route. 1. Introduction
The experimental results demonstrate that spent lead paste could be well converted into high purity metal lead via the cooperative electrochemical reduction and desulfurization approaches during the direct electrolysis process.