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ArticleName Microwave energy for gold ore processing
DOI 10.17580/tsm.2021.01.03
ArticleAuthor Sanakulov K. S., Fuzaylov O. U.

Navoi Mining and Metallurgical Works, Navoi, Uzbekistan:

K. Sanakulov, General Director, Professor, Doctor of Technical Sciences, e-mail:


Navoi State Mining Institute, Navoi, Uzbekistan:
O. U. Fuzaylov, Assistant Professor at the Chair of Metallurgy, PhD, e-mail:


Quite a few studies have been carried out that look at the application of microwave energy for material processing in various spheres. Microwaves can selectively and quickly heat the target bulk material thanks to its dielectric properties. Gold ores have a complex mineral composition and the effect of microwaves is different on different minerals. This enables to heat selected areas of the rock causing a strong thermal stress. This leads to microcracks occurring at the mineral boundaries resulting in weaker grains and hence better grinding performance. Refractory gold concentrates contain a lot of sulphides, which get hot instantly when exposed to microwave radiation. Thus, microwave energy can be efficiently used to roast sulphide gold concentrates. During microwave roasting, heat conversion takes place directly in the sulphides and the reaction starts immediately. That’s why microwave roasting is a much faster process compared with convection roasting. This paper provides a brief overview of microwave energy used for gold ore and concentrate processing and describes the behaviour of minerals in the microwave field, as well as the results of a number of studies that looked at using microwave energy to destroy rocks, roast refractory sulphide gold concentrates and regenerate charcoals. The key advantages of microwave radiation include an easy process control, the possibility to quickly and selectively heat the product and low energy costs.

keywords Microwave processing, gold refractory ore, charcoal regeneration, sulphides, selective heating, thermal stress, microcracks, concentrate, microwave roasting

1. Kitchen H. J., Vallance S. R., Kennedy J. L. et al. Modern microwave methods in solid-state inorganic materials chemistry: from fundamentals to manufacturing. Chemical Reviews. 2014. Vol. 114, No. 2. pp. 1170–1206.
2. Sutton W. H. Microwave processing of ceramic materials. American Ceramic Society Bulletin. 1989. Vol. 68, No. 2. pp. 376–386.
3. Metaxas, A. C., Meredith R. J. Industrial microwave heating. London : Peter Peregrinus Ltd., 1983. pp. 70–73.
4. Bykov Y. V., Rybakov K. I., Semenov V. E. High temperature microwave processing of materials. Journal of Physics D: Applied Physics. 2001. Vol. 34. pp. R55–R75.
5. Tazhibaev K. T., Sultanalieva R. M. An energy saving method to grind hard ores. Gornyy informatsionno-analiticheskiy byulleten. 2015. No. 12. pp. 76–82.
6. Tazhibaev K. T., Sultanalieva R. M. Ore grinding duty changing as a function of microwave radiation duration: Analytic description. Innovatsionnaya nauka. 2015. No. 10-3. pp. 244–247.
7. Fuzaylov O. U., Asrorov A. A., Vokhidov B. R., Saidakhmedov A. A. Understanding the applicability of microwave energy for ore concentration. Bulletin of Tula State University. 2017. pp. 111–116.
8. Amankwah R. K., Khan A. U., Pickles C. A., Yen W. T. Improved grin dability and gold liberation by microwave pretreatment of a free-milling gold ore. Mineral Processing and Extractive Metallurgy. 2005. Vol. 114, No. 1. pp. 30–36.
9. Amankwah R. K., Ofori-Sarpong G. Microwave heating of gold ores for enhanced grindability and cyanide amenability. Minerals Engineering. 2010. Vol. 24. pp. 541–544.
10. Seflek C., Bayat O. Microwave-assisted grinding of Bolkardag (Nigde, Turkey) gold ore and enhanced cyanide leachability. Metallurgical Research & Technology. 2018. Vol. 115, No. 5. p. 508.
11. Haque K. E. Gold leaching from refractory ores — literature survey. Mineral Processing and Extractive Metallurgy Review. 1987. No. 2. pp. 235–253.
12. Haque K. E. Microwave irradiation pretreatment of a refractory gold concentrate. Proceedings of International Symposium on Gold Metallurgy. Winnipeg, Canada, 1987. pp. 327–339.
13. Woodcock J. T., Sparrow G. J., Bradhurst D. H. Possibilities for using microwave energy in the extraction of gold. Proceedings of the 1st Australian Symposium on Microwave Power Applications. Wollongong, Australia, 1989. pp. 139–153.
14. Nanthakumar B., Pickles C. A., Kelebek S. Microwave treatment a double refractory gold ore. Minerals Engineering. 2007. Vol. 120, No. 11. pp. 1109–1119.
15. Amankwah R. K., Pickles C. A. Microwave roasting of a carbonaceous sulphidic gold concentrate. Minerals Engineering. 2009. Vol. 22, No. 13. pp. 1095–1101.
16. Ma S. J., Luo W. J., Mo W. et al. Removal of arsenic and sulfur from a refractory gold concentrate by microwave heating. Minerals Engineering. 2010. Vol. 23, No. 1. pp. 61–63.
17. Choi N. C., Kim B. J., Cho K. et al. Microwave pretreatment for thiourea leaching for gold concentrate. Metals. 2017. Vol. 7. p. 404.
18. Zhiwei Peng, Jiann-Yang Hwang. Microwave-assisted metallurgy. International Materials Reviews. 2015. Vol. 60, No. 1. pp. 30–63.
19. Xia K., Pickles C. A. Applications of microwave energy in extractive metallurgy, a review. CIM Bulletin. 1997. Vol. 90, No. 1011. pp. 96–107.
20. Ford J. D., Pei D. C. High temperature chemical processing via microwave absorption. Journal of Microwave Power. 1967. Vol. 2, No. 2. pp. 61–64.
21. Wong D. Microwave dielectric constants of metal oxides at high temperature : MSc. Thesis. Canada : University of Alberta, 1975.
22. Tinga W. R. Microwave dielectric constants of metal oxides. Electromagnetic Energy Reviews. 1988. Vol. 1. pp. 2–6.
23. Tinga W. R. Microwave dielectric constants of metal oxides. Electromagnetic Energy Reviews. 1989. Vol. 2. pp. 349–351.
24. Koleini S. M. J., Kianoush B. K. Microwave heating applications in mineral processing. The development and application of microwave heating. INTECH, 2012. pp. 79–104.
25. Berry T. F., Bruce R. W. A simple method for determining the grindability of ores. Canadian Mining Journal. 1966. Vol. 6. pp. 385–387.
26. Huang J. H., Rowson N. A. Heating characteristics and decomposition of pyrite and marcasite in a microwave field. Minerals Engineering. 2001. Vol. 14. pp. 1113–1117.
27. Waters K. E., Rowson N. A., Greenwood R. W., Williams A. J. Characterising the effect of microwave radiation on the magnetic properties of pyrite. Separation and Purification Technology. 2007. Vol. 56, No. 1. pp. 9–17.
28. Xiaoliang Zhang, Chunbao Sun, Yi Xing et al. Thermal decomposition behavior of pyrite in a microwave field and feasibility of gold leaching with generated elemental sulfur from the decomposition of gold-bearing sulfides. Hydrometallurgy. 2018. Vol. 180. pp. 210–220.
29. Nan Hu, Wei Chen, De-xin Ding et al. Role of water contents on microwave roasting of gold bearing high arsenic sulphide concentrate. International Journal of Mineral Processing. 2017. Vol. 161. pp. 72–77.
30. Sanakulov K. S., Fuzaylov O. U., Kenbaeva Zh. A. Microwave processing of sulphide gold concentrates. Gornyy vestnik Uzbekistana. 2020. No. 1. pp. 53–56.
31. Ratnikova N. S., Pankratiev P. V. Improving the efficiency of gold and silver recovery from pyrite concentrates by applying microwave technologies. Vestnik of Nosov Magnitogorsk State Technical University. 2019. Vol. 17, No. 4. pp. 4–9.
32. Avraamides J., La Brooy S. R. Evaluation of different reactivation systems available for carbons used for gold recovery. Randol Gold Forum ‘88. Scottsdale, Arizona, 1988. pp. 321–327.
33. Bradshaw S. M., Van Wyk E. J., deSwardt J. B. Preliminary economic assessment of microwave regeneration of activated carbon for the carbon in pulp process. Journal of Microwave Power and Electromagnetic Energy. 1997. Vol. 32. pp. 131–144.

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