Efficient recovery of lead and iron from disposal residues of spent lead-acid batteries

Understanding spatial position relationships between main phases and harmful components in disposal residues of spent lead-acid batteries (DR-LABs) is critical to realize metal resources recovery. This work proposed mechanism of efficient recovery of lead and iron by identification of spatial position relationships. Results showed that there were wrapping, embedding, and loading spatial position relationships between PbS and Fe2SiO4. After the destruction of Fe2SiO4, PbS was exposed on the surface of DR-LABs. Subsequently, 98.9 wt% of lead was recovered as Pb(OH)(2)/Fe(OH)(3)/Fe(OH) (2) by acid leaching followed by pH adjustment. Meanwhile, 90.3% of iron was recovered as raw material. Experiments and DFT calculation verified that NaOH induced the formation of hydroxylated Fe2SiO4(010) surfaces and near-surface Na+ substitution, which promoted the transformation of Fe2SiO4 to FeO. Overall, the proposed mechanism could be a promising support to efficient recover lead and iron from DR-LABs.

Automated summary

This study proposed a mechanism for efficient recovery of lead and iron in the disposal residues of spent lead-acid batteries by identifying their spatial position relationships. The results showed that lead and iron could be recovered in high yields through acid leaching and pH adjustment. The formation of hydroxylated Fe2SiO4 surfaces induced by NaOH was found to promote the transformation of Fe2SiO4 to FeO.