Zinc recovery by chlorination leach

• US 4,206,023 A
• Filed: 05/12/1978
• Issued: 06/03/1980
• Est. Priority Date: 05/12/1978
• Status: Expired due to Term

• Current Assignee: Occidental Research Corporation (Occidental Petroleum Corporation)
• Original Assignee: Occidental Research Corporation (Occidental Petroleum Corporation)
• Inventors: Au, Robert W.
• Primary Examiner(s): Hearn, Brian E.
• Application Number:
  US05/905,128
• Time in Patent Office: 753 Days
• Field of Search: 423/101, 423/103, 423/109, 423/110, 75/104, 75/120, 204/118
• US Class Current: 205/606
• CPC Class Codes: C22B 19/22 with leaching with acids
• CPC Class Codes: C22B 19/26 Refining solutions containing zinc values, e.g. obtained by leaching zinc ores treatment or purification of solutions by liquid-liquid extraction, by ion exchange or by adsorption C22B3/00
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

A process is disclosed for the separation and recovery of zinc from material in which it is contained as a sulfide. Zinc sulfide containing material is chlorinated in an aqueous medium in the presence of elemental chlorine and ferric/ferrous ions to form a solution containing zinc chloride, iron chloride and elemental sulfur. The solution is treated with elemental chlorine and alkali to precipitate the iron (e.g. at about pH 3 to 4). Zinc chloride is recovered from the solution by means known to those skilled in the art such as by electrolysis. The precipitated iron is recycled for use as a secondary chlorinating solution to treat the solid residue of the initial chlorination leaching step.

Claims

1. A process for recovering zinc from material containing zinc sulfide which comprises:

(a) partially chlorinating the zinc sulfide containing material in aqueous medium including recycle from step (h) in the presence of elemental chlorine and ferric chloride to form an aqueous solution containing zinc chloride, iron chloride, solid sulfur and partially chlorinated solid residue;

(b) separating the aqueous solution from the solid residue;

(c) treating the aqueous solution with elemental chlorine and an alkali to precipitate ferric hydroxide;

(d) separating the ferric hydroxide from the aqueous solution;

(e) recovering zinc from the aqueous solution;

(f) dissolving the ferric hydroxide in an acidic medium to form a secondary leaching solution;

(g) leaching additional zinc from the solid residue in the presence of the secondary leaching solution and chlorine to form a recycle solution containing zinc chloride and iron chloride; and

(h) returning the recycle solution to step (a).

2. The process of claim 1 wherein the alkali is calcium hydroxide.

3. The process of claim 1 wherein alkali is added for providing a pH to the aqueous solution of about 3 to about 4 for precipitating ferric hydroxide.

4. The process of claim 1 wherein the acidic medium is an aqueous solution of an acid selected from the group consisting of hydrochloric acid, sulfuric acid and nitric acid.