Sodium Lingo-Sulfonate and Sodium Dodecyl-Sulfate Mixtures Influence on Zinc Concentrate Pressure Leaching and Zinc Electro-Winning

This paper is describing an investigation of sodium lingo-sulfonate and sodium dodecyl-sulfate mixtures influence on zinc concentrates high temperature oxidative pressure leaching and zinc electro-winning. For this purpose, surfactants concentration at leaching tests was varied from 200 to 800 mg∙l-1. It was established that the maximum zinc extraction (99 %) at leaching was achieved in the presence of mixture containing 800 mg∙l-1 lignosulfonate and 200 mg∙l-1 sodium dodecyl-sulfate. Therefore, this mixture can be recommended for high temperature oxidative pressure leaching of zinc concentrates. Sulfur-sulfide pellets formation also was observed at a low lingo-sulfonate concentration (200 mg∙l-1) in a mixture with sodium dodecyl-sulfate. This phenomenon can lead to emergency shut down of autoclave. It was observed that the mixture usage of 800 mg∙l-1 lignosulfonate and 200 mg∙l-1 sodium dodecyl-sulfate had no significant impact on zinc current efficiency, it was in the rage of 92-93 %. The mixture usage of 200 mg∙l-1 lignosulfonate and 600 mg∙l-1 sodium dodecyl-sulfate allowed to increase current efficiency up to 95 %. Increasing sodium dodecyl-sulfate concentration in mixtures with lignosulfonates leads to decrease of current efficiency, to formation of deep pores and defects on cathode zinc surface.