TDTs "Project Institute", Ural Federal University, Yekaterinburg, Russia:

M. G. Viduetsky, Deputy Director for Science, e-mail: vid.magr@mail.ru
I. F. Garifulin, Chief Specialist
V. A. Maltsev, Director, Doctor of Technical Science
A. P. Purgin, Head of the Technological Department

Development and industrial application of pneumatic flotation machines is one of the main directions in development of flotation equipment. Some aspects of the evolutionary development of pneumatic flotation machines of the KFM series from the first generation to the modern plants are highlighted.
The main stages of modernization of pneumatic flotation machines of the KFM series are:
– optimization of geometric proportions of working chambers in order to "strengthen" the design parameters that determine the rate of formation and removal of the foam product;
– development and implementation of an original design of the gas-lift aerators with increased reliability;
- creation and application of a modern automatic control system based on programmable controllers;
– simplification of the design with an exception of "weak spots" (bottom squeezing devices, aerolifts, etc.).
The specified approach to modernize flotation plants of KFM series of the first generation allowed to develop on their basis a line of modern machines which combine principles of operation of flotation and gravity-floatation plants and distinguished by a number of advantages. Column-type flotation machines, in comparison with mechanical and pneumomechanical ones, as a rule, produce foam products with a higher content of useful component due to some reduction in recovery from the operation. Therefore, most companies manufacturing such plants recommend to use them in treatment operations. It is shown that on FPM flotation machines operating after KFM machines, higher (by 2.9% (abs.)) copper recovery was obtained at higher quality of the foam product. The total extraction of copper according to the scheme using the KFM machine in the main flotation due to the synergistic effect is also higher (by 6.1% (abs)). This is due to the fact that some of the smallest bubbles are carried away with the chamber product of KFM and float in subsequent flotation machines, accelerating the flotation process in them. Modern KFM industrial flotation machines have been successfully implemented at a number of Russian and foreign enterprises.

1. Chernykh S. I. Creation of flotation machines of pneumatic type and experience of their application at dressing plants. Moscow : TsNIITsEI, 1995. 151 p.
2. Rubinstein J. Column Flotation : Processes, Designs and Practices. USA/United Kingdom: Gordon and Breach Science Publishers, 1995. 312 p.
3. Fardis Nakhaei, Mehdi Irannajad. Application and comparison of RNN, RBFNN and MNLR approaches on prediction of flotation column performance. International Journal of Mining Science and Technology. 2015. Vol. 25, Iss. 6. pp. 983–990.
4. Navia D., Villegas D., Cornejo I., de Prada C. Real-time optimization for a laboratory-scale flotation column. Computers & Chemical Engineering. 2016. Vol. 6, Iss. 4. pp. 62–74.
5. Newcombe B. Comparison of flash and column flotation performance in an industrial sulphide rougher application. Minerals Engineering. 2016. Vol. 96–97. pp. 203–214.
6. Yianatos J., Vinnett L., Panire I., Alvarez-Silva M., Díaz F. Residence time distribution measurements and modelling in industrial flotation columns. Minerals Engineering. 2017. Vol. 110, Iss. 15. pp. 139–144.
7. Harbort G., Clarke D. Fluctuations in the popularity and usage of flotation columns. Minerals Engineering. 2017. Vol. 100. pp. 17–30.
8. Lavrinenko А. А. Modern flotation machines for mineral raw materials. Gornaya tekhnika. 2008. No. 1. pp. 186–195.
9. Lavrinenko А. А. State and trends of development of floatation machines for solid mineral concentration in Russia. Tsvetnye Metally. 2016. No. 11. pp. 19–26.
10. Jameson G. J. New directions in flotation machine design. Minerals Engineering. 2010. No. 23. pp. 835–841.
11. Viduetsky M. G., Panshin A. M., Maltsev V. A., Garifulin I. F. et al. Application of pneumatic flotation machines CFM for dressing non-ferrous metals and zinc cakes. XXVII International Mineral Processing Congress – IMPC 2014. Santiago, Chile. p. 203.
12. Viduetsky M. G., Maltsev V. A., Purgin A. P., Garifulin I. F. et al. Operating flotation cells of the KFM series in the head of full-scale copper, copper-zinc, lead-zinc ore concentration circuits. XXIX International Mineral Processing Congress – IMPC 2018. Moscow, Russia. p. 125.
13. Rubinsteyn Yu. B. Foam separation and column flotation. Moscow : Nedra, 1989. 304 p.
14. Handbook on ore beneficiation. Special and auxiliary processes. Edited by O. S. Bogdanov, V. I. Revnivtsev. Moscow : Nedra, 1983. 376 p.
15. Barskiy L. А., Kozin V. Z. System analysis in mineral processing. Moscow : Nedra, 1978.
16. Maksimov I. I., Borkin А. D., Emelyanov М. F. Study of the influence of chambers depth on technological indicators of flotation in a column flotation machine. Obogashchenie Rud. 1986. No. 4. pp. 27–30.
17. Viduetskiy М. G., Garifulin I. F. Maltsev V. А., Purgin А. P. Technology for cleaning of mine, undercut, circulating and waste water in mining and metallurgical enterprises. Tsvetnye Metally. 2017. No. 8. pp. 9–14. DOI: 10.17580/ tsm.2017.08.01.
18. Viduetskiy М. G., Garifulin I. F. Maltsev V. А., Purgin А. P. Modular pilot units based on KFM series column floatation cells. Obogashchenie Rud. 2018. No. 6. pp. 45–50. DOI: 10.17580/or.2018.06.08