Thiosulfate-copper-ammonia leaching of pure gold and pressure oxidized concentrate

• Autorzy: Porvali A. , Rintala L. , Aromaa J. , Kaartinen T. , Forsen O. , Lundstrom M.

Identyfikatory

DOI

10.5277/ppmp170231

• Języki publikacji: EN

Abstrakty

EN

In this research cyanide-free leaching of pure gold and pressure oxidized refractory gold concentrate by thiosulfate-copper-ammonia solutions were examined. A quartz crystal microbalance (QCM) was used to study gold leaching as a factorial series where the best gold leaching rate (2.987 mg/(cm2∙h)) was achieved with a solution consisting of 0.2 M (NH4)2S2O3, 1.2 M NH3, 0.01 M CuSO4 and 0.4 M Na2SO4. Temperature had the greatest effect on the gold leaching rate. An increase in thiosulfate concentration (0.1–0.2 M) increased gold dissolution. The combined effect of temperature and ammonia concentration had a statistically significant effect on the gold leaching rate at 0.1 M M2S2O3. Combination of applied potential and NH3:S2O3 ratio had a statistically significant effect on the gold leaching rate at 0.2 M M2S2O3. An increase in applied potential decreased the gold dissolution rate at low ammonia concentrations but increased it at high concentrations. A pressure oxidized gold concentrate was leached for 6 hours in the batch reactor leaching experiments. The effect of rotative velocity (1.26–1.56 m/s) and slurry density (10–30 wt%) was investigated at the following leaching parameters: 0.2 M Na2S2O3, 0.6 M NH3, 0.01 M CuSO4, 0.4 M Na2SO4. Lower slurry density (10 wt%) resulted in a higher Au leaching efficiency. An increase in the rotation rate did not have an effect on the final Au leaching recovery. The best Au leaching efficiency (89%) was achieved with 590 rpm mixing, 1.56 m/s rotative velocity and 10 wt% slurry density.

Słowa kluczowe

EN

gold leaching; thiosulfate; quartz crystal microbalance

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Physicochemical Problems of Mineral Processing
• Rocznik: 2017
• Tom: Vol. 53, iss. 2
• Strony: 1079--1091
• Opis fizyczny: Bibliogr. 50 poz., rys., tab.

Twórcy

autor

Porvali A.

• Department of Materials Science and Engineering, Aalto University, PO Box 16200, 00076 Aalto, Finland

autor

Rintala L.

• Department of Materials Science and Engineering, Aalto University, PO Box 16200, 00076 Aalto, Finland

autor

Aromaa J.

• Department of Materials Science and Engineering, Aalto University, PO Box 16200, 00076 Aalto, Finland

autor

Kaartinen T.

• Department of Materials Science and Engineering, Aalto University, PO Box 16200, 00076 Aalto, Finland
• VTT Technical Research Centre of Finland, Biologinkuja 7, 02150 Espoo, Finland

autor

Forsen O.

• Department of Materials Science and Engineering, Aalto University, PO Box 16200, 00076 Aalto, Finland

autor

Lundstrom M.

• Department of Materials Science and Engineering, Aalto University, PO Box 16200, 00076 Aalto, Finland

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