Technical University of UMMC, Verkhnyaya Pyshma, Russia:

A. B. Lebed, Head of the Department, e-mail: a.lebed@tu-ugmk.com
R. I. Verkhodanov, Engineer
Z. A. Lebed, Lead Expert

Uralmekhanobr JSC, Yekaterinburg, Russia:
A. A. Metelev, Chief Engineer

Acidic recirculation water and effluents generated by the mining industry and bearing heavy metals can have a significant environmental impact on this region. Due to high concentrations of non-ferrous metals (5.2–300 mg/dm³ Cu; 50–450 g/dm³ Zn), such waters can be used as a raw material for producing concentrates for further recovery of metals from them. This study looked at the recirculation water of the Soryinsk tailings pod, the underspoil waters of the Novo-Shemursk deposit and the Urupsky GOK mine waters. The aim of the study is to develop a process for selective extraction of copper into a product that can be further processed into a final product. The most common techniques used to remove ions of heavy non-ferrous metals from industrial wastewater include neutralization techniques. In this case, however, a considerable share of non-ferrous metals get wasted. At the same time, reagent techniques (e.g. sulphidation in the acidic pH region) enable to selectively extract such metals into concentrates that can then be used in the conventional non-ferrous metal production technology. A sulphur solution in sodium hydroxide was used as a sulphidizer for selective extraction of copper from polycomponent wastewater. The sulphur solution was produced at the temperature of 115–120 ^oC, the mass ratio NaOH:S of 1:1 and the sulphur concentration of 350 g/dm³. Use of sulphur dissolved in sodium hydroxide helped extract copper in the form of sulphides from complex solutions. It resulted in a high recovery of copper (94–99.9%) and a high-concentration copper concentrate (8.9–27.5%). It was found that iron (III) interacts with sulphide ions forming elemental sulphur, which can be reused for conditioning of copper concentrate in sodium hydroxide. Thus, the sulphur can be reused and the concentration of copper can be increased to 24%. The physical properties of particles in copper sulphide concentrates determine the high rate of solid phase precipitation from the slurry. Sulphide particles are characterized with a high negative charge (–80…–100 mV) and the size of the 90% of the particles reaching 68.9 μm. The authors developed a process flow diagram for extracting copper from low-grade complex solutions. The process involves regular addition of sulphidizer to the existing water flow, detention of a solid copper phase and, when necessary, conditioning of copper concentrate.

1. Timofeev K. L., Lebed A. B., Maltsev G. I. Treatment of industrial wastewaters and contaminated waters generated by mining and metallurgical sites. The practices of UMMC-Holding LLC: A guide for university students. Moscow : YUNITI-DANA, 2019. 224 p.
2. Solozhenkin P. M., Deliyanni E. A., Bakoyannakis V. N., Zouboulis A. I., Matis K. A. Removal of heavy metal ions from wastewater. Vodoochistka. 2008. No. 6. pp. 34–39.
3. Kurdiumov V. R., Timofeev K. L., Lebed A. B., Maltsev G. I. Technology of integrated treatment of mine water with accompanying extraction of nonferrous metals. Tsvetnye Metally. 2017. No. 12. pp. 25–29. DOI: 10.17580/tsm.2017.12.03.
4. Kurdiumov V. R., Timofeev K. L., Krayukhin S. A. Treatment of mine water using reverse osmosis technology. Vodosnabzhenie i sanitarnaya tekhnika. 2018. No. 11. pp. 48–56.
5. Özverdi A., Erdem M. Cu, Cd and Pb adsorption from aqueous solutions by pyrite and synthetic iron sulphide. Journal of Hazardous Materials. 2006. Vol. 137. pp. 626–632.
6. Kolesnikov V. A., Kokarev G. A., Varaksin S. O. Potential application of electrochemical techniques for local treatment of solutions and flush water and for recovery of non-ferrous metals. Low-waste and resource saving processes in electroplating. Moscow : Mat. MdaGO, 1988. 31 p.
7. Vurdova N. G., Fomichev V. T. Electrodialysis of natural and waste waters. Moscow : ASV, 2001. 144 p.
8. Chanturiya V. A., Solozhenkin P. M. Galvanochemical techniques for industrial water treatment. Theory and practice. Moscow : IKTs “Akademkniga”, 2005. 204 p.
9. Svetlov A. V., Minenko V. G., Samusev A. L., Salakhov E. M. Purification of mine water using electrochemical coagulation technology at Kola MMC’s Severny mine. Tsvetnye Metally. 2019. No. 11. pp. 52–56. DOI: 10.17580/tsm.2019.11.06.
10. Filatova E. G. Removal of heavy metal ions from waste water: A review of techniques based on physicochemical processes. Izvestiya Vuzov. Prikladnaya Khimiya i Biotekhnologiya. 2015. No. 2.
11. Sajeda A. Al-Saydeha, Muftah H. El-Naasa, Syed J. Zaidib. Copper removal from industrial wastewater: A comprehensive review. Journal of Industrial and Engineering Chemistry. 2017. Vol. 56. pp. 35–44.
12. Lewis A. E. Review of metal sulphide precipitation. Hydrometallurgy. 2010. No. 2. pp. 222–234.
13. Zhao M., Xu Y., Zhang C. et al. New trends in removing heavy metals from wastewater. Applied Microbiology and Biotechnology. 2016. Vol. 100. pp. 6509– 6518.
14. Shakitaev A., Narembekova A. K. Possible precipitation recovery of copper in the form of copper sulphide particles from industrial solutions. 21^st Century Metallurgy As Viewed by Young People: Proceedings of the 5^th International Conference of Young Researchers and Undergraduates. Donetsk, 2019. pp. 71–72.
15. Khalezov B. D., Vatolin N. A., Ovchinnikova L. A., Pavlichenko G. A. Understanding the extraction of copper and zinc sulphides from copper-zinc sulphuric acid solutions. Gornyy informatsionno-analiticheskiy byulleten. 2005. No. 1. pp. 261–265.
16. Khalezov B. D., Vatolin N. A., Makurin Yu. N., Bykov N. A. Recovering zinc from leach liquors of copper-zinc ores. Gornyy informatsionno-analiticheskiy byulleten. 2005. No. 3. pp. 260–265.
17. Khalezov B. D., Nezhivykh V. A., Ovchinnikova L. A. Recovery of zinc from heap leach liquors using hydrosulphides: Pilot tests. Gornyy informatsionno-analiticheskiy byulleten. 2005. No. 4. pp. 278–279.
18. Klyushnikov A. M. Study of copper and zinc extraction from underspoil water. Metallurg. 2019. No. 11. pp. 8–14.
19. Khalezov B. D., Gavrilov A. S., Petrova S. A., Ovchinnikova L. A. Nickel extraction from solutions using sodium hydrosulfide. Tsvetnye Metally. 2019. No. 3. pp. 33–38. DOI: 10.17580/tsm.2019.03.04.
20. Wang L. P., Chen Y. J. Sequential precipitation of iron, copper, and zinc from wastewater for metal recovery. Journal of Environmental Engineering. 2019. No. 1. pp. 1–11.
21. Wang L. P., Ponou J., Matsuo S. et. al. Selective Precipitation of Copper and Zinc over Iron from Acid Mine Drainage by Neutralization and Sulfidization for Recovery. Society of Materials Engineering for Resources for Japan. 2014. No. 2. pp. 136–140.
22. Laptev Yu. V., Sirkis A. L., Kolonin G. R. Sulphur and sulphidation in hydrometallurgical processes. Moscow : Nauka, 1987.