Determination of arsenic speciation in secondary zinc oxide and arsenic leachability

The species of arsenic in secondary zinc oxide generated from fuming furnace were investigated. The results revealed that there are mainly three types of secondary zinc oxide based on three arsenic species. The main phase of As is As2O3 in type I, zinc arsenite (Zn(AsO2)2) in type II and lead arsenate (Pb(As2O6), Pb4As2O9) in type III, respectively. Selective leaching of zinc oxide of type II was carried out. The leaching rate of As kept at 65%-70% with 30 g/L NaOH and L/S ratio of 3 at 20 °C for 1 h, while the losses of Pb and Zn were both below 1%.