National University of Science and Technology MISIS (Moscow, Russia):
Shekhirev D. V., Associate Professor, Candidate of Engineering Sciences, Senior Researcher, shekhirev@list.ru

Due to the growing complexity of ore processing, equipment and technologies with higher separation efficiency are currently in demand. Flotation machines with a countercurrent flow of slurry and bubbles are increasingly being used. Yet still, certain issues related to optimizing flows in a flotation cell by adjusting the cell height and feed point depth remain insufficiently studied. Pilot tests of a countercurrent flotation machine with a jet-ejector aerator in rougher flotation at a facility of Phosphorit Industrial Group LLC have demonstrated an increase in separation efficiency after a chamber height adjustment from 3.5 to 5.0 m with a 1.5 m deeper feed point. The mass fraction of P₂O₅ in the froth product increased from 20–22 to 25–27 % with a decrease in froth yield from 32–35 to 21–24 %. The flotation tail grades correspond to those of the dump waste product (1.00 ± 0.39% P₂O₅ according to the data on 116 samples); the load of cleaner operations has also been normalized. An original sampler designed by B. S. Chertilin was used to test the mineral load of bubbles at different depth points in the cell. The results indicate the extreme nature of the load distribution with a monotonous increase in P₂O₅. This confirms the main role of the process of predominant shedding of waste rock particles from the bubbles in the concentration zone (above the feed point) with the higher separation efficiency achieved.

1. Sastri S. R. S. Column flotation: Theory and practice. Froth flotation : Recent trends. Jamshedpur: IIME, 1998. pp. 44–63.
2. Dobby G. Column flotation. SGS minerals services. Technical paper 2002-23. 10 p.
3. Viduetsky M. G., Garifulin I. F., Maltsev V. A., Purgin A. P. Some aspects of modernization of pneumatic flotation machines of a column type. Tsvetnye Metally. 2021. No. 5. pp. 14–22. DOI: 10.17580/tsm.2021.05.02.
4. Viduetsky M. G., Garifulin I. F., Topaev G. D. Ways of improvement of column flotators. Gornyi Zhurnal. 2008. No. 6. pp. 80–83.
5. Jameson Сell. Taking on a challenge. Powerful, efficient, high intensity flotation technology. Brisbane: Glencore Technology, 2015. 12 p.

6. Baranov V. F. Overview of operating practices of foreign concentrators processing sulfide and mixed copper ores. Obogashchenie Rud. 2020. No. 3. pp. 43–47. DOI: 10.17580/or.2020.03.08.
7. Maksimov I. I., Borkin A. D., Koltunova T. E., Khudyakov V. M., Khaidov V. V. Implementation of column flotation machines FP-25 SM in nis matte separation. Tsvetnye Metally. 1995. No. 8. pp. 73–75.
8. Matiolo E., Couto H. J. B., Lima N., Silva K., Amanda K. S., Freitas A. S. Improving recovery of iron using column flotation of iron ore slimes. Minerals Engineering. 2020. Vol. 158. DOI: 10.1016/j.mineng.2020.106608.
9. Brylyakov Yu. E., Kostrova M. A. Introduction of quarter-circle flotation machines for preparation of apatitenefeline ores. Gornyi Zhurnal. 2010. No. 2. pp. 52–54.
10. Teague A. J., Lollback M. C. The beneficiation of ultrafine phosphate. Minerals Engineering. 2012. Vol. 27–28. pp. 52–59.

11. Kozlov V. A., Novak V. I. The use of column flotation in the coal industry. Gorny Informatsionno-analiticheskiy Byulleten'. 2011. No. 4. pp. 277–283.
12. Kuznetsova I. A., Maksimov I. I. Development of the processing technology for porphyry copper ores of the Tominsky deposit. Obogashchenie Rud. 2021. No. 2. pp. 9–14. DOI: 10.17580/or.2021.02.02.
13. Belov A. S., Shenderovich E. M. Design cases for Russia’s largest mining and processing enterprises for copper ores. Obogashchenie Rud. 2021. No. 6. pp. 48–52. DOI: 10.17580/or.2021.06.08.
14. Baranov V. F. Designs of new operating copper processing plants: process types, equipment selection, industry trends. Obogashchenie Rud. 2021. No. 1. pp. 44–52. DOI: 10.17580/or.2021.01.08.
15. Chanturia V. A. Scientific substantiation and development of innovative approaches to integrated mineral processing. Gornyi Zhurnal. 2017. No. 11. pp. 7–13. DOI: 10.17580/gzh.2017.11.01.
16. Nikitin A. Yu., Eliseeva R. A., Yushina T. I., Kalugin A. I. Design and operation of SOMEX column flotation machines for processing the Khibiny apatite-nepheline ore. Gornyi Zhurnal. 2021. No. 12. pp. 37–43. DOI: 10.17580/gzh.2021.12.07. 
A. P. Modular pilot units based on KFM series column flotation cells. Obogashchenie Rud. 2018. No. 6. pp. 45–51. DOI: 10.17580/or.2018.06.08.
18. Vadlakonda B., Mangadoddy N. Hydrodynamic study of three-phase flow in column flotation using electrical resistance tomography coupled with pressure transducers. Separation and Purification Technology. 2018. Vol. 203. pp. 274–288.
19. Chul-Hyun Park. Estimation of rate constants and mixing characteristics in flotation columns. Applied Sciences. 2021. Vol. 11, Iss. 21. DOI: 10.3390/app112110084.
20. Maksimov I. I., Borkin A. D., Emelyanov M. F. Study of the effect of chamber depth on the technological parameters of flotation in a column flotation machine. Obogashchenie Rud. 1986. No. 4. pp. 27–30.
21. Pat. SU 472692.
22. Pat. SU 1253666.
23. Pat. SU 1233941.
24. Pat. SU 1676664.
25. Maksimov I. I., Borkin A. D., Emelyanov M. F. Application of column flotation machines in cleaning operations during the beneficiation of non-ferrous metal ores. Obogashchenie Rud. 1988. No. 6. pp. 36–39.