N. A. Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia

S. А. Kondratiev, Head of the Laboratory of Mineral Processing and Technological Ecology, Doctor of Technical Sciences, e-mail: kondr@misd.ru

Based on the mechanism of operation of a physically sorbed collector, the position of the profile of the flotation area in lgC – pH coordinates is explained. The reasons for the limitation of the flotation area at low and high concentrations of collector are shown. The conditions for achieving high floatability of sodium oleate in the neutral and slightly alkaline pH range and dodecylamine in the alkaline pH range are substantiated. The effect of the pH of the flotation system and the hydrolysis of collector salt on lowe ring the surface tension of the solution and increasing the extraction of the useful component into the concentrate has been established. A new understanding of the work of a physically sorbed collector in the elementary act of gamma flotation is proposed. It is shown that the contact angle of wetting is not a factor characterizing the floatability of the target component. The work performed by a collector that is physically absorbed on the mi neral and desorbed at the gas-liquid interface is the main factor determining the floatability of the required component. The conditions for achieving selective separation of minerals have been established. It is shown that the attachment of a physically sorbed collector is an additional and necessary condition for high extraction of the target mineral. The selectivity of mineral separation will be determined by the difference between the critical surface tensions of the flotation solution and the selective attachment of the physically sorbed collector to the target mineral. The selectivity of the attachment of a physically sorbed collector to the target minerals of non-ferrous and rare-earth ores is assessed using a comparative analysis of the reagent interaction energies on separable minerals in a flotation solution. The research opens the way to the development of innovative technologies aimed at increasing the selectivity of mineral separation, which is of paramount importance for obtaining critical raw materials.
The work was carried out within the framework of the research project (state registration number 121051900145-1).

1. Kondratyev S. A., Gavrilova T. G. The role of physical sorption in increasing the extraction and selectivity of the useful component in foam flotation. Tsvetnye Metally. 2025. No. 8. pp. 13–21.
2. Abramov A. A. Flotation methods of enrichment. 3rd edition. Moscow : MGGU, 2008, pp. 670.
3. Abramov A. A. The role of collector sorption forms in the elementary act of flotation. Fiziko-tekhnicheskie problem razrabotki poleznykh iskopaemykh. 2005. No. 1. pp. 96–108.
4. Bogdanov O. S., Vainshenker I. A., Podnek A. K. et al. On the hydrophilicity of the mineral surface and the forms of fortification of collectors. Obogashchenie Rud. 1969. No. 4. pp. 23–28.
5. Sutherland K. L., Wark I. W. Principles of flotation. Melbourne : Austr. Inst. Min. Metall., 1955. 489 p.
6. Klassen V. I., Tikhonov S. A. The effect of sodium oleate on the flotation properties of the surface of air bubbles. Tsvetnye Metally. 1960. No. 10. pp. 4–8.
7. Wark E., Wark I. Influence of micelle formation on flotation. Nature. 1939. Vol. 143. pp. 856.
8. Rossi E.E., de Arrieta C., Ciribeni V., Ferretti R. J. Depression areas in flotation graphs produced by the adsorption of a second layer in froth flotation. Minerals & metallurgical processing. 1991. Vol. 8. pp. 7–15.
9. Rogers J., Sutherland K.L. Activation of minerals and adsorption of collectors. Trans. AIME. 1946. Vol. 169. pp. 317–333.
10. Bleier A., Goddard E. D., Kulkarni R. D. Adsorption and critical flotation conditions. J. Colloid Interface Sci. 1977. Vol. 59. pp. 490–504.
11. Somasundaran P. The relationship between adsorption at different interfaces and flotation behavior. Transactions AIME. 1968. Vol. 241. pp. 105–108.
12. Somasundaran P., Fuerstenau D. W. On the incipient flotation condition. Transactions AIME. 1968. Vol. 241. pp. 102–104.
13. Finch J. A., Smith G. W. Dynamic surface tension of alkaline dodecylamine solutions. Journal of Colloid and Interface Science. 1973. Vol. 45, No. 1. pp. 81–91.
14. Finch J. A., Smith G. W. Bubble-solid attachment as a function of bubble surface tension. Canadian Metallurgical Quarterly. 1975. Vol. 14, Iss. 1. pp. 47–51.
15. O’Brien R. N., Feher A. I., Leja J. Spreading of monolayers at the airwater interface. II. Spreading speeds for alcohols, acids, esters, sulphonates, amines, quaternary ammonium ions, and some binary mixtures. J. Colloid Interface Sci. 1976. Vol. 56, No. 3. pp. 474–482.
16. O’Brien R. N., Feher A. I., and Leja J. Interferometric and hydrodynamic flow profiles produced in water by a spreading monolayer. J. Colloid Interface Sci. 1975. Vol. 51, No. 3. pp. 366–372.
17. Mielczarski J. A., Cases J. M., Bouquet E., Barres O., Delon J. F. Nature and structure of adsorption layer on apatite contacted with oleate solution. I. Adsorption and fourier transform infrared reflection studies. Langmuir. 1993. Vol. 9. pp. 2370–2382.
18. Kondratiev S. A. The collective strength and selectivity of the flotation reagent. Fiziko-tekhnicheskie problem razrabotki poleznykh iskopaemykh. 2021. No. 3. pp. 133–147.
19. Kondratiev S. A. Approaches to the selection of flotation reagentscollectors. Fiziko-tekhnicheskie problem razrabotki poleznykh iskopaemykh. 2022. No. 5. pp. 109–124.
20. Kondratiev S. A., Tsitsilina D. M. Selectivity of flotation extraction of a calcium-containing useful component by precipitation of an oxyhydryl collector. Fiziko-tekhnicheskie problem razrabotki poleznykh iskopaemykh. 2023. No. 2. pp. 112–122.
21. Polkin S. I. Enrichment of ores and placers of rare and precious metals. Moscow : Nedra, 1987. 428 p.
22. Castro F. H., Borrego A. G. Modification of surface tension in aqueous solutions of sodium oleate according to temperature and pH in the flotation bath. Journal of Colloid and Interface Science. 1995. Vol. 173. pp. 8–15.
23. Powney J. The properties of detergent solution. Part I. The influence of hydrogen ion concentration on the surface tension of soap solution. Transactions of the Faraday Society. 1935. Vol. 31. pp. 1510–1521.

24. Pugh R., Stenius P. Solution chemistry studies and flotation behaviour of apatite calcite and fluorite minerals with sodium oleate collector. International Journal of Mineral Processing. 1985. Vol. 15. pp. 193–218.
25. Laskowski J. S. A new approach to classification of flotation collectors. Canadian Metallurgical Quarterly. 2010. Vol. 49, Iss. 4. pp. 397–404.
26. Zhai J., He H., Chen P., Song L. et al. Flotation behaviours of ilmenite and associated solution chemistry properties using saturated fatty acids as the collector. Separations. 2025. Vol. 191. pp. 12.
27. Fa K., Jiang T., Nalaskowski J., Miller J. D. Interaction forces between a calcium dioleate sphere and calcite/fluorite surfaces and their significance in flotation. Langmuir. 2003. Vol. 19, Iss. 25. pp. 10523–10530.
28. Avdokhin V. M., Gubin S. L. Reverse cationic flotation of fine iron ore concentrates. GIAB. 2006. No. 24. pp. 324–331.
29. Bogdanov O. S., Mikhailova N. S. Investigation of the interaction of a cationic collector with quartz iron minerals. Issledovanie deistviya flotatsionnykh reagentov. Trudy instituta Mekhanobr. 1965. Iss. 135. pp. 139–156.
30. Takeda S., Usui S. Adsorption of dodecylammonium ion on quartz in relation to its flotation. Colloids and Surfaces. 1987. Vol. 23, Iss. 1-2. pp. 15–28.
31. Yoon R.-H., Yordan J. L. Induction time measurements for the quart zamine flotation system. Journal of colloid and Interface Science. 1991. Vol. 141, No. 2. pp. 374–383.
32. Stechernesser H., Geidel Th., Weber K. Expansion of three-phase contact line after rupture of thin non-symmetrical liquid films I. Relationship between rate of expansion and radius of three-phase contact. Colloid & Polymer Sci. 1980. Vol. 258. pp. 109–110.
33. Hornsby D. T., Leja J. Critical surface tension and the selective separation of inherently hydrophobic solids. Colloids and Surfaces. 1980. Vol. 1. pp. 425–429.
34. Yarar B., Kaoma J. Estimation of the critical surface tension of wetting hydrophobic solids by flotation. Colloids and Surfaces. 1984. Vol. 11, Iss. 3-4. pp. 429–436.
35. Kelebek S., Smith G. W. Selective flotation of inherently hydrophobic Minerals by controlling the air/solution interfacial Tension. International Journal of Mineral Processing. 1985. Vol. 14. pp. 275–289.
36. Kelebek S., Finch J. A., Yörük S., Smith G. W. Wettability and floatability of galena-xanthate system as a function of solution surface tension. Colloids Surf. 1986. Vol. 20. pp. 89–100.
37. Kelebek S., Smith G. W., Finch J. A., Yörük S. Critical surface tension of wetting and flotation separation of hydrophobic solids. Separation Science and Technology. 1987. Vol. 22, Iss. 6. pp. 1527–1546.
38. Kramer A., Gaulocher S., Martins M., Leal Filho L. S. Surface tension measurement for optimization of flotation control. Procedia Engineering. 2012. Vol. 46. pp. 111–118.
39. Martins M., Leal Filho L. S., Parekh B. K. Surface tension of flotation solution and its influence on the selectivity of the separation between apatite and gangue minerals. Minerals & metallurgical processing. 2009. Vol. 26, No. 2. pp. 79–84.
40. Van Oss C. J. Acid-base interfacial interactions in aqueous media. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 1993. Vol. 78. pp. 1–49.