Resumo

YANG, W. et al. Dissolution kinetics of tellurium from gold concentrate during alkaline sulphide leaching. J. S. Afr. Inst. Min. Metall. [online]. 2019, vol.119, n.10, pp.883-890. ISSN 2411-9717.  http://dx.doi.org/10.17159/2411-9717/693/2019.

Alkaline sulphide leaching was adopted to extract tellurium from tellurium-bearing gold concentrate for the first time. The tellurium leaching kinetics were studied. The influence of average particle size, stirring speed, leaching temperature, Na₂S concentration, and NaOH concentration on the tellurium extraction were investigated. It was found that tellurium extraction could reach 79.14% under the optimum conditions: 17.77 μηι average particle size, 500 r/min stirring speed, 80 g/L Na₂S concentration, 30g/L NaOH concentration, 80°C leaching temperature, 4:1 liquid to solid ratio, and 180 minutes leaching time. The interface transfer and diffusion through the product layer or insoluble substance layer were the rate-controlling steps. The leaching kinetics equation was established, and the activation energy was 34.384 kJ/mol.

Palavras-chave : Gold concentrate; tellurium leaching; alkaline suphide leaching; kinetics.

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