North-Caucasian Mining and Metallurgical Institute (State Technological University), Vladikavkaz, Russia:

S. I. Evdokimov, Associate Professor of the Department of Mineral processing, e-mail: eva-ser@mail.ru
T. E. Gerasimenko, Associate Professor of the Department of Technological Machines and Equipment

The enrichment technology for both the impregnated ores of the Norilsk-1 deposit and the slag of Copper Plant was developed. A new configuration of the enrichment scheme is proposed: a rough concentrate is first extracted from the half part of the raw material (the first flotation stream), and then, it is mixed with the second half part of the raw materials (the second flotation stream), thus enabling the production of finished crude concentrate. Increasing the steepness of separation characteristics and the quality of the fractional composition of the raw materials due to mixing o f the feedstock and the crude concentrate wa found to be responsible for the enhanced recovery of valuable components. In the second flotation stream, a mixture of air and hot water steam called a steamair mixture is used as the gas phase. In the flotation stage by the steam-air mixture, the boundary layers of bubbles are heated by the heat of condensation. According to the Cassie-Baxter state model, an air layer is retained in the form of nano- and microbubbles during wetting of the minerals surfaces in the cavities of their relief. The physical consequence of the conjugate heat and mass transfer during condensation and vapor evaporation in bubbles is their coalescence with surface nanobubbles, i.e. the formation of a flotocomplex by the most efficient mechanism — coalescent. The driving factor providing a change in the stability of wetting films with increasing temperature of the boundary layer of bubbles and the result of flotation is the surface forces of structural origin with the participation of the surface layer of air. Application of the developed technology allows increasing the extraction of copper and nickel in similar concentrates by more than 5%. The possibility of joint enrichment of ores and slags is presented and discussed.

1. Chanturia V. A., Lavrinenko A. A., Sarkisova L. M., Ivanova T. A., Glukhova N. I., Shrader E. A., Kunilova I. V. Sulfhydryl phosphorus-containing collectors in flotation of copper-nickel platinum-group metals. Journal of Mining Science. 2015. Vol. 51, Iss. 5. pp. 1009–1015.
2. Evdokimov S. I., Evdokimov V. S. Efficient flotation technology for natural cooper-nickel and waste material. Gornyi Zhurnal. 2016. No. 2. pp. 74–78.
3. Udoeva L. Yu., Selivanov E. N., Klyayn S. E., Selmenskikh N. I. Granulation of coper-nickel converter matters: dispersity, microstructure and reactive capacity. Non-ferrous Мetals. 2014. No. 1. pp. 18–22.
4. Dyachenko V. T., Bryukvin V. A., Tsybin O. I., Vinetskaya T. N., Mantsevich M. I., Lapshina G. A. Development of combined flotation-hydrometallurgical technology for enrichment of disseminated deposits of the Norilsk industrial region. Tsvetnaya metallurgiya. 2013. No. 5. pp. 49–52.
5. Evdokimov S. I., Evdokimov V. S. Processing ores and anthropogenic Cu – Ni feedstock with application of technology of jet air-stream flotation. Russuan Journal of Non-Ferrous Metals. 2015. Vol. 56, Iss. 3. pp. 229–234.
6. Masloboev V. A., Seleznev S. G., Makarov D. V., Svetlov A. V. Assessment of eco-hazard of copper-nickel ore mining and processing waste. Journal of Mining Science. 2014. Vol. 50, Iss. 3. pp. 559–572.
7. Rybnikova L. S., Rybnikov P. A., Tarasova I. V. Geoecological Challenges of Mined-Put Open Pit Area Use in the Ural. Journal of Mining Science. 2017. Vol. 53, Iss. 1. pp. 181–190.
8. Huang Hongjun, Zhu Haifeng, Hu Yuehua. Hydrophobic surface of copper from converter slag in the flotation system. International Journal Mining Science and Technology. 2013. Vol. 23, No. 4. pp. 613–617.
9. Roy S., Datta F., Rehani S. Flotation of copper sulfide from copper smelter slag using multiple collectors and their mixtures. International Journal of Mineral Processing. 2015. Vol. 143. pp. 43–49.
10. Kondratyev S. A., Rostovtsev V. I., Bochkarev G. R., Pushkareva G. I., Kovalenko K. A. Justification and development of innovative technologies for integrated processing of complex ore and mine waste. Journal of Mining Science. 2014. Vol. 50, Iss. 5. pp. 959–973.
11. Evdokimov S. I., Evdokimov V. S. Metal recovery from old tailings. Journal of Mining Science. 2015. Vol. 50, Iss. 4. pp. 800–808.
12. Panshin A. M., Evdokimov S. I., Artemov S. V. Investigations in the field of flotation with a steam-air mixture. Russuan Journal of Non-Ferrous Metals. 2012. Vol. 53, Iss. 1. pp. 1–7.
13. Tao X., Chun-bao S. Aerosol flotation of low-grade refractory molybdenum ores. International Journal of Minerals Metallurgy and Materials. 2012. Vol. 19, No. 12. pp. 1077–1082.
14. Heydari G., Moghaddam M. S., Tuominen M., Fielden M., Haapanen J., Makela J. M., Claesson Her. M. Wetting hysteresis induced by temperature changes: Supercooled water on hydrophobic surfaces. Journal of Colloid and Interface Science. 2016. Vol. 468. pp. 21–23.
15. Rabbani H. S., Joekar-Niasar V., Shokri N. Effects of intermediate wettability on entry capillary pressure in angular pores. Journal of Colloid and Interface Science. 2016. Vol. 473. pp. 34–43.
16. Wn Y., Cai M., Li Zh., Wang H., Pei X., Zhon F. Slip flow of diverse liquids on robust superomniphobic surfaces. Journal of Colloid and Interface Science. 2014. Vol. 414. pp. 9–13.
17. Tie L., Guo Z., Li W. Optimal design of superhydrophobic surfaces using a paraboloidmicrotexture. Journal of Colloid and Interface Science. 2014. Vol. 436. pp. 19–28.
18. Simonsen A. C., Hansen Per L., Klosgen B. Nanobubbles give evidence of incomplete wetting at a hydrophobic interface. Journal of Colloid and Interface Science. 2004. Vol. 273. pp. 291–299.
19. Hampton M. A., Nguyen A. V. Nanobubbles and the nanobubblebridgind capillary force. Advances in Colloid and Interface Science. 2010. Vol. 154, Iss. 1–2. pp. 30–55.
20. Wang J., Yoon R.-H., Morris J. AFM surface force measurements conducted between gold surfaces treated in xanthate solutions. International Journal of Mineral Processing. 2013. Vol. 122. pp. 13–21.
21. Nilsson A., Pettersson M. Perspective on the structure of liquid water. Chemical Physics. 2011. Vol. 389, Iss. 1–3. pp. 1–34.
22. Pan L., Jung S., Yoon R.-H. Effect of hydrophobicity on the stability of the wetting films of water formed on gold surfaces. Journal of Colloid and Interface Science. 2011. Vol. 361. pp. 321–330.
23. Eigeles M. A. Basis of flotation of non-sulfide minerals. Мoscow : Nedra, 1964. 408 p.