RECOVERY OF ZINC FROM ZINC BEARING SULPHIDIC ORES AND CONCENTRATES BY CONTROLLED OXIDATION ROASTING

摘要

ROGERS, BERESKIN & PARRTITLE: RECOVERY OF ZINC FROM ZINC BEARING SULPHIDIC ORESAND CONCENTRATES BY CONTROLLED OXIDATION ROASTINGINVENTORS: MURRY C. ROBINSONDONALD W. KIRKDR. BRUCE JUEABSTRACT OF THE DISCLOSUREA process is described for the controlled oxidationroasting of zinc bearing sulphidic ores and concentrates byadjusting the furnace temperature and residence timetogether with the oxygen availability to the sulphide reten-tion requirements in the calcine. The obtained calcine issubsequently subjected to various physical and chemical pro-cess steps to separate the unreacted sulphides which arethen dead roasted and treated for zinc recovery, accordingto one embodiment of the process. In another embodiment theseparated, unreacted sulphides are returned to the control-led oxidation roasting step.The chemical separation process steps includesulphur dioxide leaching. In one embodiment zinc is prefer--2-entially dissolved as sulphite and the solution obtained isfurther treated for zinc recovery. In other embodimentssulphuric acid, or ammonical ammonium carbonate or similarleaching reagents are used for the preferential dissolutionof the zinc oxide present in the calcine.