Sustainable Mining and Metallurgy

This paper studied the new process of solid-phase reduction of lead sulfate in a low-chloride system using white offgas dust acid leaching residue as raw material and iron powder as reducing agent. It examined the effects on lead recovery posed by single-factor conditions such as liquid-solid ratio, calcium chloride concentration, iron powder dosage, and reduction temperature and time. The study obtained the following optimum reduction conditions: liquid-solid ratio of 2∶1, calcium chloride concentration of 40g/L, iron powder dosage of 1.2 times the theoretical amount of lead, reduction temperature of 70℃ and reduction time of 3h. Under these conditions, the lead recovery rate was more than 92%.