Pressure acid leaching

The example being considered under zinc ore pertains to acid pressure leaching of zinc concentrates developed by Sherritt Gordon Mines Ltd. in Canada. The basic reaction involved is... 

It will be interesting to record some of the evaluatory remarks as regards the process. There is no doubt that the direct acid pressure leach route is an attractive alternative to the conventionally followed process for zinc sulfide processing. Incentives for its adoption on a commercial scale are the reduced capital cost and production of sulfur in its most favored form, the elemental form. Nevertheless, no process is perfect and acid pressure leach process is not an exception. There are at least two aspects of the process which pose some problems. The first is the behavior of impurities, and the second is the disposal of iron. 

Chalkley, M. E. Toirac, I. L. The acid pressure leach process for nickel and cobalt laterite. Part I review of operations at Moa. Hydrometallurgy and Refining of Nickel and Cohalt, Annual Hydrometallurgy Meeting of CIM, 27th, Sudbury, Ont., Aug. 17-20, 1997, 341-353. 

Das, G. K. Acharya, S. Anand, S. Das, R. P. Acid pressure leaching of nickel-containing chromite over burden in the presence of additives. Hydrometallurgy 1995, 39, 117-128. 

Georgiou, D. Papangelakis, V. G. Sulfuric acid pressure leaching of alimonitic laterite chemistry and kinetics. Hydrometallurgy 1998, 49, 23 16. 

Papangelakis, V. G. Georgiou, D. Rubisov, D. H. Control of iron during the sulfuric acid pressure leaching of limonitic laterites. Iron Control and Disposal, Proceedings of the International Symposium on Iron Control in Hydro-metallurgy, 2nd, Ottawa, Oct. 20-23, 1996, 263-274. 

Rubisov, D. H. Papangelakis, V. G. Sulfuric acid pressure leaching of laterites—prediction of metal solubilities and speciation analysis at temperature. EPD Congress 1999, Proceedings of Sessions and Symposia held at the TMS Annual Meeting, San Diego, Feb. 28-Mar. 4, 1999, 535-546. 

Rubisov, D. H. Krowinkel, J. M. Papangelakis, V. G. Sulphuric acid pressure leaching of laterites—universal kinetics of nickel dissolution for limonites and limonitic/saprolitic blends. Hydrometallurgy 2000, 58, 1-11. 

The tendency of gold(III) chlorocomplexes to adsorb on iron (hydrous) oxides that tend to form via in situ precipitation in acidic pressure leaching operations needs to be controlled to avoid undesirable metal losses. 

Gray, P. M. J. Acid pressure leaching of uranium ores. Proc. 1st Int. Conf. on the Peaceful Uses of Atomic Energy, Geneva, 195S. Paper 986. 

D. Georgiou, V. Papangelakis, Characterization of limonitic laterite and solids during sulfuric acid pressure leaching using transmission electron microscopy . Minerals Engineering, 17 (2004), pp. 461 63. 

The following conclusions can be drawn from the precipitation studies of nickel and cobalt from a copper depleted Cu-Ni-Co sulphate solution generated from acid pressure leaching of a synthetic matte containing Cu-Ni-Co-Fe-S ... 

Cobalt can be recovered from nickel-sulfide concentrates or nickel matte by the Sherritt-Gordon ammonia leaching process in Fort Saskatchewan, Alberta, Canada, and it is also recovered from sulfuric-acid pressure leaching of laterites. In both cases, cobalt is obtained in nickel-free liquor by reduction with hydrogen under elevated pressure and temperature (Section 2.2). 

Soldenhoff, K., Hayward, N., and Wilkins, D. 1998. Direct solvent extraction of cobalt and nickel from laterite-acid pressure leach liquors. In EPD Congress 1998, ed. B. Mishra, 153-165. Warrendale, PA The Minerals, Metals and Materials Society. 

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