Institute of Chemistry and Chemical Technology SB RAS (Krasnoyarsk, Russia):
Zashikhin A. V., Researcher, Candidate of Engineering Sciences, obog2006@yandex.ru

This paper covers certain areas of application of hydraulic classification for separating particles by density and grain size. The results of respective studies are presented with the aim of developing a fundamentally new approach in the field of gravity concentration, and namely, in hydroclassification in relatively still water. It is shown that chamber-type hydraulic classifiers used in the study have low efficiency due to the irregularity of the horizontal carrier flow, which variates by a factor of up to 60 in depth and along the length of the device. The paper describes the main difference distinguishing the proposed new approach from the traditional ones, which consists in organizing hydraulic classification with a uniform horizontal carrier flow without flow rate changes in the separation zone. A uniform horizontal carrier flow, implemented in a rather original way in a number of new patented hydraulic classifiers and a magnetic fluid separator, allows producing continuous lateral hydrodynamic pressure on the settling and/or suspended particles, equally along the height and length of the separation zone. The article provides the basic equation for calculating the speed of a horizontal carrier flow by the characteristics of the lightest particle in the mix being separated, taking into account the correction for the deviation in its settlement trajectory from a straight line during soaring. It is shown that a classification efficiency of 98.6 % or more may be obtained at cutoff sizes of 0.2 and 0.044 mm, and the values of the Hancock–Luyken criterion may exceed 97 % with a recovery of 98 %.

1. Kizevalter B. V. Theoretical foundations of gravitational beneficiation processes. Мoscow: Nedra, 1979. 295 p.
2. Bogdanovich A. V. Theoretical foundations and methods of increasing the efficiency of separation during gravitational ore beneficiation: dis. for the degree of Doctor of Engineering Sciences. St. Petersburg, 2002. 342 p.
3. Tohry A., Dehghani A., Hosseini-nasab M. Removal of fine gangue minerals from Chador-Malu iron concentrate using hydroseparator. Physicochemical Problems of Mineral Processing. 2017. Vol. 53, Iss. 1. pp. 250–263.
4. Lösch P., Nikolaus K., Antonyuk S. Fractionating of finest particles using cross-flow separation with superimposed electric field. Separation and Purification Technology. 2021. Vol. 257. pp. 117820–117826.
5. Tripathy S. K., Bhoja S. K., Raghu Kumar C., Suresh N. A short review on hydraulic classification and its development in mineral industry. Powder Technology. 2015. Vol. 270. pp. 205–220.
6. Lösch P., Nikolaus K., Antonyuk S. Classification of fine particles using the hydrodynamic forces in the boundary layer of a membrane. Chemie Ingenieur Technik. 2019. Vol. 91, Iss. 11. pp. 1656–1662.
7. Ryabov Yu. V., Delitsyn L. M., Ezhova N. N., Sudareva S. V. Methods for beneficiation of ash and slag waste from coal-fired thermal power plants and ways for their commercial use (A review). Teploenergetika. 2019. No. 3. pp. 3–24.
8. Polotov I. Zh., Sabirov B. Z., Minovarova A. K. Research of the washability of coal from the Torgoi-Dobo deposit by hydraulic classification. Vestnik Oshskogo Gosudarstvennogo Universiteta. 2021. Vol. 1, No. 1–2. pp. 90–96.
9. Saimaganbetova N. K., Serik Zh. S., Andreeva O. S., Estauova Zh. K., Degodya E. Yu. Improving the technology for beneficiation of South-Kempirsai deposit chromite ores. Aktualnye Problemy Sovremennoy Nauki, Tekhniki i Obrazovaniya. 2020. Vol. 11, No. 1. pp. 6–9.
10. Dormeshkin O. B., Kenzhibayeva G. S., Shalataev S. S., Zhantasov K. T., Shapalov Sh. K., Zhantasova D. M. Investigation of the process of hydraulic classification of phosphorus skime to obtain the production of glyphosates. Izvestiya Natsionalnoy Akademii Nauk Respubliki Kazakhstan. Seriya Khimii i Tekhnologii. 2017. No. 6. pp. 97–102.
11. Intogarova T. I. Improving the flotation classification of copper ores based on the beneficiation of foam products in narrowing troughs: dis. for the degree of Candidate of Engineering Sciences. Ekaterinburg, USMU. 2021. 119 p.
12. Kolesnikov R. S., Apukhtina I. V., Ryzhikh T. A. Analysis of technique and technology for the separation of iron-containing composition processing products. IX International youth forum «Education. Science. Production». 2017. pp. 1279–1283.
13. Belyshev A. K., Myasnikova N. F., Koverdyaev O. N., Tarasov A. N. Development of technology for beneficiation of garnet-containing raw materials. Gorny Informatsionnoanaliticheskiy Byulleten'. 2000. No. 2. pp. 52–54.
14. Zhurkovsky M. E., Chashchilov D. V., Blaznov A. N. Justification of the choice of dispersion analysis methods and study of solid-phase particles of flowing tailings from floatation beneficiation of complex ores. Yuzhno-Sibirskiy Nauchnyi Vestnik. 2019. No. 4. pp. 19–27.
15. Zashikhin A.V., Verkhoturov M. V., Samoilov V. G., Golsman D. A., Perfilieva N. S., Kuzmichev D. V. On the problems of deep gravity beneficiation of mineral raw materials. Khimicheskaya Tekhnologiya. 2008. Vol. 9, No. 11. pp. 583–585.
16. Franchuk V. P., Bondarenko A. A. Horizontal classifiers. Fundamentals of theory and calculation. Dnepropetrovsk: NMU, 2016. 111 p.
17. Reference book on beneficiation of ores. Vol. I. Preparatory processes. Мoscow: Nedra, 1982. 367 p.
18. Zashikhin A. V. Gravitational separation of mineral particles in uniform transport flows: dis. for the degree of Candidate of Engineering Sciences. Irkutsk, 2010. 166 p.
19. Chan T. T. K., Huisman S. G., Blay Esteban L., Shrimpton J. S., Ganapathisubramani B. Settling behaviour of thin curved particles in quiescent fluid and turbulence. Journal of Fluid Mechanics. 2021. Vol. 922. DOI: 10.1017/jfm.2021.520.

20. Pat. 2535322 Russian Federation.
21. Fomenko T. G. Gravitational processes of mineral beneficiation. Мoscow: Nedra, 1966. 261 p.
22. Zashikhin A. V. Gravity separation in equal transport flow with periodic crowded and free settling. Sovremennye Problemy Nauki i Obrazovaniya. 2013. No. 1. p. 187.
23. Pat. 2758825 Russian Federation.
24. Pat. 2634768 Russian Federation.