Anglesite flotation: a study for lead recovery from zinc leach residue

The recovery of lead from zinc leach residues (as PbSO4) by flotation is of interest in the zinc plants. Therefore, at the first stage of the present study, anglesite flotation behavior and its surface characteristics have been investigated. The interaction of natural and sulfidized anglesite with potassium amyl xanthate (KAX), Aerofloat and Aerophine have been investigated as a function of concentrations of amyl xanthate, Aerofloat, Aerophine, and sodium sulphide as well as pH through micro-flotation studies. Flotation recovery is affected by pH, collector concentration, and sulfidization degree. Sulfidization reduced the collector consumption roughly 8 times for the collectors studied. At the second stage, the recovery of lead from a zinc leach residue of an oxidic ore was investigated through batch flotation studies. The residue was leached with water before sulfidization to eliminate its soluble compounds. The highest zinc elimination occurred at low pH. At the sulfidization-flotation stage, the effect of different parameters such as sodium sulfide, KAX, and sodium silicate concentration as well as pH were studied. The lead recovery was significantly affected by the sodium sulfide concentration. The sulfide consumption for the leach residue was 3 times more than that for the pure anglesite. De-sliming and cleaning increased the grade of lead in the concentrate.