Noranda Inc.

Carole Allen

Gezinus Van Weert

Serge Payant

Peter Kondos

George Houlachi

Anthonie Van Sandwijk

Francis Belanger

An apparatus and a process for producing zinc oxide from a zinc-bearing material are provided. The process comprises the steps of leaching the complex sulfide material with hydrochloric acid, ferric chloride, and oxygen; precipitating iron from the leach solution using lime and oxygen; removing copper, silver, cadmium, cobalt and lead from the leach solution by cementation with zinc dust; precipitating zinc oxide from the leach solution using lime; and regenerating HCl from a calcium chloride leach filtrate solution to regenerate hydrochloric acid and precipitate gypsum. Related processes for recovering copper, silver, lead, and iron from complex sulfide materials and for recovering lead from residue by solubilizing lead chloride and precipitating it with lime are also provided.

Reduction of zinc oxide from complex sulfide concentrates using chloride processing

The present invention relates to an apparatus and a process for producing zinc oxide from a zinc-bearing material. The process according to the present invention comprises the steps of leaching the complex sulfide material with hydrochloric acid and oxygen; precipitating iron from the leach solution using magnesium oxide and oxygen; removing copper, silver, cadmium, cobalt and lead from the leach solution by cementation with zinc dust; precipitating zinc oxide from the leach solution using magnesium oxide; and spray roasting the remaining magnesium chloride leach solution to regenerate hydrochloric acid and magnesium oxide. The present invention further relates to processes for recovering copper, silver, lead, and iron from complex sulfide materials.

Production of zinc oxide from complex sulfide concentrates using chloride processing

A process for recovery of copper from a copper residue obtained during purification of a zinc sulfate solution comprises leaching the copper residue in a concentrated sulfuric acid solution in the presence of an oxidant at a temperature of between 60.degree. and 80.degree. C. and separating the solids from the leach solution, electrowinning copper from the leach solution, returning the electrolyte solution to the initial leaching stage to initiate dissolution of the copper residue, and bleeding a portion of the electrolyte solution to reduce the concentration of impurities in the solution.

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Pierrefonds, Canada

Carole Allen