Shevchenko Н.O., Cholyshkina V.V., Sukhariev V. V., Kurilov V.S., Lebed Н.B. The rate of constrained particles deposition in a wide range of suspension densities in the laminar-turbulent operating modes

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Parent Category: Geo-Technical Mechanics, 2023

Category: Geo-Technical Mechanics, 2023, Issue 164

Geoteh. meh. 2023, 164, 103-115

https://doi.org/10.15407/geotm2023.164.103

 

THE RATE OF CONSTRAINED PARTICLES DEPOSITION IN A WIDE RANGE OF SUSPENSION DENSITIES IN THE LAMINAR-TURBULENT OPERATING MODES

Shevchenko Н.O., Cholyshkina V.V., Sukhariev V. V., Kurilov V.S., Lebed Н.B.

M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine

UDC 532.5.011: 622.33: 622.752.3

Language: English

Abstract. The rate of constrained fall of mineral particles in suspensions of different densities is necessary for calculating the design and operating modes of gravity concentrating equipment. During hydraulic classification and separation, a mixed, laminar-turbulent, flow regime is observed in real pulps. There are no theoretical velocity formulas for such a regime, and most of the known semi-experimental and experimental formulas have limited application. This article proposes a new method for comparing different formulas with each other in a wide range of suspension densities. The method uses an analytical calculation of the hydraulic characteristics of the medium - porosity, concentration and viscosity. What is new is that all these characteristics depend on only one indicator - the density of the suspension, which is easily determined in practice by weighing a pulp sample. In these calculations, the weighted average density of heterogeneous particles in suspension is used. A feature of the method is the approximation of the analyzed calculation formulas to the conditions of free fall in order to obtain only one control point and compare it with known experimental data. This method allows to set the limits of the application of formulas depending on the density of the suspension. The choice of a more precise formula is necessary for the design hydraulic devices for the classification and separation of mineral suspensions and finely ground composite raw materials. The application of this method for the most common formulas of Ergan and Todes-Rosenbaum is shown. It was found that the latter formula іs actually not suitable for dilute suspensions with a density below 1.65 g/cm³. A new linear equation for calculating the rate of constrained particles deposition is proposed, which provides high accuracy in a wide range of suspension densities. The resulting equation has a simple form and, together with an analytical calculation of the characteristics of the medium, forms a system of linear equations for calculating the rate of constrained particles deposition of any size and density in mineral pulps of different densities. The calculation of the velocity of constrained settling and the ascent of particles is the basis for the design of hydraulic classifiers and separators for mineral dressing. Such calculations are necessary for determining of hydraulic devices optimal modes and monitoring indicators during their operation.
Keywords: mineral suspension, density, rate of constrained deposition.

REFERENCES

1. Bogdanov, O.S., Olevsky, V.A., et al. (1972), Spravochnik po оbogascheniju rud [Handbook for ore dressing], Vol.1, Nedra, Moscow.

2. Lyashchenko, P.V. (1940), Gravitatsionnyye metody obogashcheniya [Gravity enrichment methods], State Science and Technology Publishing House, Moscow-Leningrad.

3. Happel, J. and Brenner, H. (1965), Low Reynolds number hydrodynamics, Prentice-Hall, New York University.

4. Nazimko. E. I. (1997), Nauchnyye osnovy topologii sistem osvetleniya oborotnykh vod ugleobogatitel'nykh fabrik [Scientific bases of topology of systems of clarification of circulating waters of coal preparation plants], Abstract of Doctor of Technical Sciences (D.Sc.) dissertation, Donetsk State technical university, Donetsk.

5. Polulyakh, A.D., Buchatsky, A.S., Vyrodov, S.A. and Polulyakh, D.A. (2016), Obogashcheniye uglya v magnetitovoy suspenzii: monografiya [Enrichment of coal in magnetite suspension: monograph], NSU, Dnepropetrovsk.

6. Kelbaliev, G. I. (2015), "Fundamentals of the theory of sedimentation and floating of solid particles, drops and bubbles in an isotropic turbulent flow", Azerbaijan Chemical Journal, no. 2, pp. 6–27.

7. Radkevich, E.V., Lukashev, E.A. and Vasilyeva, O.A. (2019), "Hydrodynamic instabilities and nonequilibrium phase transitions", Reports of the Academy of Sciences, Vol. 486 (5), pp. 537–542. https://doi.org/10.31857/S0869-56524865537-542

8. Einstein, V.G., Zakharov, M.K., Nosov G.A., et al. (1999), Obshchiy kurs protsessov i apparatov khimicheskoy tekhnologii [General course of processes and apparatuses of chemical technology], Vol.1, Chemistry, Moscow.

9. Goroshko, V.D., Rosenbaum, R.B. and Todes, O.M. (1958), "Approximate laws of the hydraulics of the suspended layer and constrained fall", Izvestiya VUZOV. Oil and gas, no. 1, рр. 125–131.

10. Bulat, A. F., Nadutiy, V.P., Chelyshkina, V.V. and Kurilov, V.S. (2020), "A Determination of characteristic properties of mineral suspension for calculating the particle velocity", Geotekhnicheskaya Mekhanika [Geo-Technical Mechanics], no.152, pp. 172–183. https://doi.org/10.15407/geotm2020.152.172

About authors:

Shevchenko Нeorhii Oleksandrovych, Doctor of Technical Sciences (D.Sc.), Head of Department of Mechanics of Mineral Processing Machines and Processes, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine),Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Cholyshkina Valentyna Vasylivna, Candidate of Technical Sciences (Ph.D.), Senior Researcher of Department of Mechanics of Mineral Processing Machines and Processes, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine),Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Sukharіev Vitaliі Vitaliіovych, Candidate of Technical Sciences (Ph.D.), Senior Researcher in Department of Mechanics of Mineral Processing Machines and Processes, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Kurilov Vladislav Serhiiovych, Junior Researcher in Department of Mechanics of Mineral Processing Machines and Processes, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Lebed Hennadii Borysovych, Junior Researcher in Department of Mechanics of Mineral Processing Machines and Processes, M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM of the NAS of Ukraine),Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

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