Journals →  Tsvetnye Metally →  2014 →  #4 →  Back

ArticleName Peculiarities of pressure oxidation of gold-sulphide and carbon-containing concentrates in the presence of chlorides
ArticleAuthor Zaytsev P. V., Fomenko I. V., Pleshkov M. A., Chugaev L. V., Shneerson Ya. M.

“Scientific-Engineering Center “Gidrometallurgiya” JSC, Saint Petersburg, Russia:

Zaytsev P. V., Researcher
Fomenko I. V., Researcher, phone: 8(812) 600-77-45
Pleshkov M. A., Leading Researcher
Chugaev L. V., Leading Researcher
Shneerson Ya. M., Chief Executive Officer


Certain conditions of the pressure oxidation (POX) process, such as high temperature and pressure, make possible to carry out an intensive oxidation of sulfides in refractory gold ores and concentrates. However, there was made a definition that in case of processing of some materials, the POX method leads to irreversible gold losses. Investigation of this phenomenon revealed that the reasons of gold losses are connected with combined presence of carbonaceous substance in the material and chlorideion in the POX solution. This is confirmed by the thermodynamic calculations, which also show the possible ways of this problem solving. This article demonstrates the combined negative effect of organic carbon (contained in the material) and chloride-ion (dissolved in the POX solution) on gold recovery from refractory gold concentrates of Malomyr deposit. There was studied the effect of partial sulfur oxidation on the POX indicators. Obviously, sulfides' oxidation was increased together with increasing of amount of gold, exposed to cyanide leaching. There was observed that relationship between gold recovery and sulfides' oxidation has an extreme behavior, which is more shown under high chloride concentrations in the POX solution. The controlled partial oxidation of sulfides allows to avoid the significant gold losses, formed during POX process. According to this, increasing of gold recovery by 10% and more becomes possible. There was studied the addition of carbonates to the POX feed slurry, which makes possible to control the POX slurry acidity, which – in turn – affects the gold recovery. Decreasing of POX solution acidity leads to an elevated gold recovery level, even when the chloride concentration is relatively low. There were carried out the pilot tests of the continuous POX technology, which confirmed the key relationships, obtained in the laboratory. The experimental data was compared to results of thermodynamic calculations.

keywords Refractory gold, organic carbon, pressure oxidation, HKF-theory, batch tests, pilot tests

1. Thomas K. G. Pressure oxidation overview. Developments in Mineral Processing. 2005. Vol. 15. pp. 346–369.
2. Naboychenko S. S., Shneerson Ya. M., Chugaev L. V., Kalashnikova M. I. Avtoklavnaya gidrometallurgiya tsvetnykh metallov (Pressure hydrometallurgy of non-ferrous metals). Ekaterinburg : Ural State Technical University — Ural Polytechnic Institute, 2008. Vol. 1. 376 p.
3. Simmons G. L. Pressure oxidation process development for treating carbonaceous ores at Twin Creeks. Proceedings of Randol Gold Forum’96. Golden, Colorado, 1996. pp. 199–208.
4. Simmons G. L. et al. Pressure Oxidation Problems and Solutions: Treating Carbonaceous Gold Ores Containing Trace Amounts of Chloride (Halogens). Mining Engineering. 1998. Vol. 50 (1). pp. 69–73.
5. J. Qing Liu, Nicol M. J. Thermodynamics and kinetics of the dissolution of gold under pressure oxidation conditions in the presence of chloride. Canadian Metallurgical Quarterly. 2002. Vol. 41, No. 4. pp. 409–416.
6. Ketcham V. J., O’Reilly J. F., Vardill W. D. The Lihir Project: Process Plant Design. Minerals Engineering. 1993. Vol. 6, No. 8/10. pp. 1037–1065.
7. Zaytsev P. V., Chugaev L. V., Pleshkov M. A., Shneerson Ya. M., Klementev M. V. Avtoklavnoe okislenie zolotosoderzhashchikh kontsentratov dvoynoy upornosti (Pressure oxidation of double obstinacy gold-containing concentrates). Sbornik dokladov IV Mezhdunarodnogo kongressa “Tsvetnye metally – 2012” (Collection of reports of the IV International congress “Non-ferrous metals – 2012”). Krasnoyarsk : Verso, 2012. pp. 561–567.
8. Fomenko I. V., Pleshkov M. A., Chugaev L. V., Shneerson Ya. M. Termodinamicheskoe opisanie povedeniya zolota pri avtoklavnom okislenii sulfidnykh kontsentratov (Thermodynamic description of behavior of gold in the time of pressure oxidation of sulphide concentrates). Sbornik dokladov V Mezhdunarodnogo kongressa “Tsvetnye metally – 2013” (Collection of reports of the V International congress “Non-ferrous metals – 2013”). Krasnoyarsk : Verso, 2013. pp. 374–386.
9. Gomeza M. A., Assaaoudi H., Becze L., Cutler J. N., Demopoulos G. P. Vibrational spectroscopy study of hydrothermally produced scorodite (FeAsO4·2H2O), ferric arsenate sub-hydrate (FAsH; FeAsO4·0.75H2O) and basic ferric arsenate sulfate (BFAS; Fe[(AsO4)1 – x(SO4)x(OH)xwH2O). Journal of Raman Spectroscopy. 2010. Vol. 41. pp. 212–221.
10. Meretukov M. A. Zoloto: khimiya, mineralogiya, metallurgiya (Gold: chemistry, mineralogy, metallurgy). Moscow : Ore and Metals, 2008. 528 p.
11. Chryssoulis S. L., McMullen J. Mineralogical investigation of gold ores. Advances in gold ore processing. Under the editorship of M. D. Adams. Amsterdam : Elsevier, 2005. pp. 21–72.
12. Chen T. T., Cabri L. J., Dutrizak J. E. Characterizing gold in refractory sulfide gold ores and residues. Journal of Metals. 2002. Vol. 54, No. 12. pp. 20–23.
13. Chugaev L. V., Korzhenevskaya M. M. Izvestiya vuzov. Tsvetnaya metallurgiya — Russian Journal of Non-ferrous Metals. 1972. No. 5. pp. 57–62.
14. Zhuchkov I. A., Mineev G. G., Aksenov A. V. Serosoderzhashchie rastvoriteli blagorodnykh metallov v geokhimicheskikh i metallurgicheskikh protsessakh (Sulfur-containing dissolvents of noble metals in geochemical and metallurgical processes). Irkutsk : Publishing House of Irkutsk State Technical University, 2010. 388 p.
15. Nicol M. J. The Anodic Behaviour of Gold: Part I. Oxidation in Acidic Solutions. Gold Bulletin. 1980. Vol. 13 (2). pp. 46–55.
16. Diaz M. A., Kelsall G. H., Welham N. J. Electrowinning Coupled to Gold Leaching by Electrogenerated Chlorine I. Au (III) – Au (I)/Au Kinetics in Aqueous Cl2/Cl Electrolytes. Journal of Electroanalytical Chemistry. 1993. Vol. 361. pp. 25–38.
17. Putnam G. L. Chloride as a Solvent in Gold Hydrometallurgy. Engineering and Mining Journal. 1944. Vol. 145 (3). pp. 70–75.
18. Helgeson H. C., Kirkham D. H., Flowers G. C. Theoretical prediction of the thermodynamic behavior of aqueous electrolytes at high pressures and temperatures: IV. Calculation of activity coefficients, osmotic coefficients, and apparent molal and standard and relative partial molal properties to 600 oС and 5 kb. American Journal of Science. 1981. Vol. 281. pp. 1249–1516.
19. Tanger J. С., Helgeson H. С. Calculation of the thermodynamic and transport properties of aqueous species at high pressures and temperatures: revised equation of state for the standard partial molal properties of ions and electrolytes. American Journal of Science. 1988. Vol. 288. pp. 19–98.
20. Machesky M. L., Andrade W. O., Rose A. W. Adsorption of gold(III)-chloride and gold(I)-thiosulfate anions by goethite. Geochimica et Cosmochimica Acta. 1991. Vol. 55, Iss. 3. pp. 769–776.
21. Vlassopoulos D., Wood S. A. Gold speciation in natural waters: I. Solubility and hydrolysis reactions of gold in aqueous solution. Geochimica et Cosmochimica Acta. 1990. Vol. 54, Iss. 1. pp. 3–12.
22. Lyakh S. I., Klementev M. V., Shneerson Ya. M. Avtoklavnaya pilotnaya ustanovka dlya provedeniya polupromyshlennykh ispytaniy po okisleniyu sulfidnykh flotatsionnykh kontsentratov zolotosoderzhashchikh rud (Pressure pilot unit for carrying out of semi-industrial testings on oxidation of sulphide flotation concentrates of gold-containing ores). Sbornik dokladov IV Mezhdunarodnogo kongressa “Tsvetnye metally – 2012” (Collection of reports of the IV International Congress “Non-ferrous metals – 2012”). Krasnoyarsk : Verso, 2012. pp. 584–589.

Language of full-text russian
Full content Buy