PbSO4decomposition kinetic and phase transformation mechanism during lead waste recycling

PbSO4is the main component of lead paste, lead smoke and other lead-containing solid wastes. It usually matches with the primary lead concentrate to co-smelt for lead extraction, mostly in the oxidation smelting stage. The lead waste quickly experiences different temperature and atmosphere fields from feeding the furnace to the completion of the reactions. This work investigated PbSO4decomposition kinetic and phase transformation mechanism during lead waste pyrometallurgical recycling. The results show that the activation energy of the decomposition reaction of PbSO4at 800 ℃∼1000 ℃ in Ar atmosphere is 121.35 kJ/mol. The PbSO4decomposition reaction in Ar and Air is a multi-step decomposition process, which may undergo PbSO4→ PbO·PbSO4→ 2PbO·PbSO4→ 4PbO·PbSO4→ PbO. PbO is not generated through direct decomposition of PbSO4. The results are expected to provide guidance for the lead wastes co-smelting process to achieve a target PbSO4decomposition product.