Recycling of Spent Lead-Acid Battery for Lead Extraction with Sulfur Conservation

Abstract

This study proposed a cleaner pyrometallurgical lead-acid battery (LAB) recycling method for lead extraction and sulfur conservation without excessive amount of SO 2 generation. Reducing atmosphere was introduced to the lead paste recycling system to selectively reduce PbSO 4 to PbS. At the same time, PbO and PbO 2 components contained in the lead paste was also reduced to metallic Pb. Then the intermediate PbS further reacted with sulfur-fixing agent, typically Fe 3 O 4 , to generate PbO and FeS. Sulfur was transformed from PbSO 4 to PbS and conserved as FeS finally. Thus SO 2 emissions and pollution were significantly eliminated. This work investigated the thermodynamic and experimental feasibility and phase conversion mechanism of this method proposed, the detailed lead extraction and sulfur fixing mechanisms were clarified, and the phase transformation and microstructural evolution processes were characterized. Additionally, bench experimental of industrial, end-of-life LAB paste was conducted to detect the lead recovery and sulfur fixation efficiency.

PbSO4 Reduction Mechanism and Gas Composition at 600–1000°C

“…PbSO 4 , as one of the dominant and refractory components in lead-containing wastes 23,24 , has a reduction behavior that not only affects lead recovery but also determines the generation and emissions of sulfurcontaining gases. Studies were devoted to dissociation of metal sulfates 25,26 , but less attention has been paid to PbSO 4 reduction.…”

Sustainable phase-conversion method for antimony extraction and sulfur conservation and waste treatment at low temperature

“…We combined an alkaline smelting (Guo et. al., 2013), a reductive sulfur-fixing extraction ( Li et al, 2019a) with an iron-containing waste co-treatment (Li et al, 2019b) and proposed an innovative phase-conversion method for antimony extraction at a low temperature of 1123 K (850 °C). Na2CO3-NaCl binary molten salt was introduced into the extraction step in order to decrease the conversion temperature (Li et al, 2016), due to its low eutectic temperature, high solvent property, good thermal stability and low reactivity (Ye et al, 2014).…”