Oxidizing leaching of complex sulphides in ammonium chloride: sphalerite leaching kinetics

Authors

  • J. L. Limpo Centro Nacional de Investigaciones Metalúrgicas (CSIC)

DOI:

https://doi.org/10.3989/revmetalm.1997.v33.i4.853

Keywords:

Leaching, Sphalerite, Kinetics, Ammonium chloride medium

Abstract


Recent studies on chloride leaching of sphalerite are rewieved. The kinetics of oxygen leaching of sphalerite in concentrated ammonium chloride solutions in the presence of cupric ion has been studied. A pure sphalerite and a zinc concentrate have been tested. 80-130 °C temperature range, the dissolution occurred according to a mixed model which assumed both diffusion through sulfur layer and a surface reaction in the shrinking core model. This is described mathematically as: [1-(1-X)1/3] + B [1[ -2/3 X-(1-X)2/3] = krt. The effect of temperature, cupric concentration and particle size on the dissolution rate were determinated. The activation energy of the rate constant kr for the pure sphalerite and zinc concentrate was found to be 66.4 and 67.6 kJ/mol respectively. The dissolution rate increased as the 0.43 power of the cupric cloride concentration. The results obtained for the effect of particle size show, such as it is predicted by the kinetic mixed model, that the rate constant kr is inversely related, and the parameter B is directly related, to particle radius.

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Published

1997-08-30

How to Cite

Limpo, J. L. (1997). Oxidizing leaching of complex sulphides in ammonium chloride: sphalerite leaching kinetics. Revista De Metalurgia, 33(4), 258–270. https://doi.org/10.3989/revmetalm.1997.v33.i4.853

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