| Publication Date |
1978 |
| Personal Author |
Dewing, H. H.; Cochran, A. A. |
| Page Count |
22 |
| Abstract |
A goal of the Bureau of Mines is to maximize the recovery of minerals and metals while minimizing pollution. To reach this goal the Bureau is conducting research to achieve major improvements in metals and minerals processing. The Bureau has investigated a laboratory-scale, ambient pressure technique which yields zinc sulfate and elemental sulfur from sphalerite (ZnS) concentrates by reaction with 80 to 85 pct sulfuric acid at 175 to 200C. The objective was to help develop an economical hydrometallurgical method of producing zinc from sulfide concentrates that would eliminate the need for sulfur dioxide air pollution controls. More than 98 pct of the zinc was recovered as zinc sulfate after 3 hr at 175C. Neutral zinc sulfate required for electrolysis was separated from the sulfuric acid solution by crystallization as ZnSO4.7H20 at 10C. Up to 80 pct of the water in the recycled electrolysis solution was removed by the crystallization process; evaporation was used to further concentrate the sulfuric acid for reuse in leaching sphalerite. Advantages of the proposed method over conventional roasting and leaching are: virtual elimination of sulfur dioxide, production of a solid sulfur byproduct, and high zinc recoveries by elimination of zinc ferrite losses. |
| Keywords |
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| Source Agency |
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| NTIS Subject Category |
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| Corporate Authors |
Bureau of Mines, Rolla, MO. Rolla Metallurgy Research Center. |
| Document Type |
Technical Report |
| Title Note |
Rept. of investigations. |
| NTIS Issue Number |
197910 |
