Gormashexport Ltd (Novosibirsk, Russia):

Bauman A. V., Deputy Director for Research, Candidate of Engineering Sciences, aleksei_bauman@mail.ru

The capacity of process slurries to form systems stable to aggregation and sedimentation under certain conditions is one of the key factors determining the performance of water recycling circuits in thickening processes at concentrating plants. The aggregation and sedimentation stability depends on the physical and chemical properties of the solid and liquid phases of the suspension, on the content of the solid phase in the slurry, on the dispersion degree of the material, on the specific surface area of the particles, etc. Despite the fact that the issues of aggregation and sedimentation stability of slurries have been widely covered both in Russian and Western literature, the generally accepted methods of laboratory practical studies are limited to investigation of the sedimentation kinetics of suspensions without determining the factors that significantly reduce the rate of separation of the liquid and solid phases, down to a complete cessation of the process. The article outlines the main factors determining the sedimentation stability of process slurries in thickening and waterrecycling sections of operating production plants and describes the most typical errors in the design and organization of the production process. The sedimentation and aggregation stability investigation methods for slurries considered in the article enable identification and prediction of the kinetics of changes in the aggregation stability of process slurries, not only at the stage of pre-design studies, but also during process audits of operating concentrating plants. A methodology is proposed for obtaining sedimentation stability data for suspensions during preliminary studies of the thickening process. Practical recommendations are given that, in many cases, help avoiding process miscalculations in the development of water-slurry circuits for thickening and water-recycling sites and preventing respective industrial accidents.

1. Bauman A. V. Concentrating plants thickening circuits and return water systems design problem areas. Obogashchenie Rud. 2016. No. 3. pp. 58–62. DOI: 10.17580/or.2016.03.10.
2. Wills B. A., Barley R. W. Mineral processing at a crossroads. Problems and prospects. Dordrecht: Martinus Nijhoff Publishers, 1986. pp. 339–381.
3. Shokhin V. N., Lopatin A. G. Gravitational methods of beneficiation. Textbook for universities. Moscow: Nedra, 1993. 350 p.
4. Concha А. F. Solid-liquid separation in the mining industry. Springer International Publishing Switzerland, 2014. 429 p.
5. Romankov P. G., Kurochkina M. I. Hydromechanical processes of chemical technology. Leningrad: Khimiya, 1982. 288 p.
6. King R. P. Modeling and simulation of mineral processing systems. USA: University of Utah, 2001. pp. 213–223.
7. Workshop on mineral processing. Textbook for universities. Bedran N. G. (ed.). Moscow: Nedra, 1991. 526 p.
8. Neizvestnykh N. N. The Birkachan and Tsokol deposits ores pulp thickening process study. Obogashchenie Rud. 2014. No. 5. pp. 27–29.
9. Kowalski W., Banas M., Kolodziejczyk K. Intensification the sedimentation process of coal suspension. XVIII International Coal Preparation Congress. Switzerland, 2016. P. 833–837.
10. Protodyakonov I. O., Chesnokov Yu. G. Hydromechanical fundamentals of chemical technology processes. Leningrad: Khimiya, 1987. 360 p.
11. Batchelor G. K. Sedimentation in a dilute dispersion of spheres. J. Fluid Mech. 1972. Vol. 52. pp. 245–268.
12. Mizra S., Richardson J. F. Sedimentation of suspension of particles of two or more sizes. Chem. Eng. Sci. 1979. Vol. 34. pp. 447–454.
13. Bauman A. V. Upon modernization of domestically produced radial thickeners. Obogashchenie Rud. 2013. No. 1. pp. 44–49.
14. Bauman A. V. Criteria of engineering efficiency of thickening flowcharts. XVIII International Coal Preparation Congress. Switzerland, 2016. pp. 107–110.
15. Shchukin E. D., Pertsov A. V., Amelina E. A. Colloid chemistry. Moscow: Vysshaya shkola, 1992. 414 p.
16. Evmenova G. L. Development of a method for estimating the surface properties of coal dispersions. Vestnik Kuzbasskogo Gosudarstvennogo Tekhnicheskogo Universiteta. 2006. No. 5. pp. 51–53.
17. GOST R 8.887—2015. State system for ensuring the uniformity of measurements (ICG). Potential of electrokinetic (zeta potential) particles in colloidal systems. Optical methods of measurement.
18. SP 31.13330.2012. Water supply. External networks and facilities.
19. GOST 19355—85. Drinking water. Methods for determination of polyacrylamide.
20. GOST 19609.0—89. Enriched kaolin. General requirements for test methods.