The Production of Electrolytic Zinc at Risdon

Abstract

As the details of this process are rather too intricate for the average student, a summary of the process has been given first, and fuller treatment of the various stages is then added for those interested. Zinc blende (ZnS) along with galena, pyrites and many other compounds is mined at Broken Hill. The zinc blende is separated from most of the galena. Then the zinc blende concentrate is roasted. The sulphur dioxide so produced is converted into sulphuric acid and the zinc oxide formed by the roasting is dissolved in sulphuric acid, a solution of zinc sulphate being obtained. Lastly the zinc sulphate solution, after careful purification, is submitted to electrolysis, zinc of a very high degree of purity (99·95 %) being obtained. The necessary power is derived from an hydro-electric power station.