titanium dioxide, calcium chloride, sodium chloride, eutectic melt, interaction.

How to Cite

Omel’chuk , A., Ivanenko , O., Pohorenko , Y., Pavlenko , T., & Skryptun, I. (2020). INTERACTION OF TITANIUM DIOXIDE WITH EUTECTIC MELT NaCl - CaCl2. Ukrainian Chemistry Journal, 86(11), 24-33.


The results of studies of the interaction of titanium dioxide with the eutectic melt of (0.48) NaCl–(0.52) CaCl2 (mol.) in the temperature range of 823–1073 K are shown. It is established that the interaction of titanium dioxide with the melt of sodium chlorides and calcium is accompanied by the formation in the salt phase of titanium compounds soluble in 1.0% solution of hydrochloric acid, and in the solid residue is recorded calcium titanate, and the number of products formed in both phases substantially. At temperatures above 923 K is formed calcium titanate, the relative amount of which increases with increasing temperature by reducing the equilibrium content of titanium compounds in the salt phase. At temperatures below 923 K, calcium titanate was not detected in the interaction products, and the content of titanium compounds in the salt phase was higher than at higher temperatures.

The absence of calcium titanate in the solid residue after prolonged isothermal contact of TiO2 with the NaCl-CaCl2 melt in the temperature range 823–923 K may be due to the fact that at such temperatures, the dissolution of titanium dioxide occurs by physical mechanism or by a mixed physicochemical mechanism. The results of the calculations by the Schroe­der-Le Chatelier equation support this. In the specified temperature range, the concentration of titanium compounds increases with tempe­rature.  Starting   from 923 K the nature of the interaction between titanium dioxide and the melt changes. Apparently at such temperatures (923–1073 K), the contribution of the chemical interaction between the components accompanied by the formation of calcium metatanate and volatile titanium compounds is dominant. The quantitative content of the phase, which in composition in the solid residue is identified as CaTiO3, increases, and the number of titanium compounds in the salt phase (based on TiO2) decreases.

The change of isobaric isothermal potential (∆G) in the temperature range of 300–1300 K of the exchange reactions between sodium chloride and calcium and titanium oxide is positive, so self-directed course is unlikely. The lowest Gibbs free energy values correspond to the reaction of the interaction of calcium chloride with titanium dioxide to form titanate or calcium oxide and tetrachloride or titanium oxochloride.


1. Ustinov V.S., Olesov Yu.G., Antipin L.N., Drozdenko V.A. Powder Metallurgy of Titanium. (Moskov: Metallurgy, 1981). [in Russian].
2. Sergeev V.V., Neroslavskaya L.L. The value of the special properties of titanium in its production and use. (Moskov: Colormet Information, 1966). [in Russian]
3. Petrunko A.N., Olesov Yu.G., Droz­den­ko V.A. Titanium in new technology. Problems of non-ferrous metallurgy. (Moskov: Metallurgy, 1979). [in Russian]
4. Sergeev V.V., Galitsky N.V., Kiselev V.P., Kozlov V.M. Metallurgy of titanium. (Moskov: Metallurgy, 1971). [in Russian]
5. Deng Guo-zhu. Discussion of the achievement and the developing trend in titanium metallurgy. Chinese Journal of Rare Metals. 2002. 26(5): 391. [in Chinese]
6. Sun Kang. Titanium Extraction. (Beijing: Metallurgical Industry Press, 2001). [in Chinese]
7. Kroll W. The Production of Ductile Titanium. Trans. Electrochem. Soc. 1940. 78: 35.
8. Korovin S.S., Zimina G.V., Reznik A.M., Bukin V.I., Kornyushko V.F. Rare and scattered elements. Chemistry and technology. In 3 book. / ed. Korovina S.S. (Moskov: MISiS, 1996). [in Russian]
9. Chervonyi I.F., Listopad D.A. Alternative technologies for the production of titanium. Metallurgy. Collection of scientific papers ZGIA. (Zaporozhye, 2010). (22): 8.
10. Fray D.J. Emerging molten salt technologies for metals production. The Journal of The Minerals, Metals & Materials Society. 2001. 52(10): 26.
11. Chen G.Z., Fray D.J., Farthing T.W. Direct electrochemical reduction of titanium dioxide to titanium molten Calcium Chloride. Nature. 2000. 407: 361.
12. Park І.І., Abiko T., Okabe T.H. Production of titanium powder directly from TiО2 in CaCl2 through an electronically mediated reaction. Journal of Physics and Chemistry of Solids. 2005. 66: 410.
13. Suzuki R.O., Ono K., Teranuma K. Calcio­thermic reduction of titanium oxide and in-situ electrolysis in molten CaCl2. Metall. Mater. Trans. B. 2003. 34:287.
14. Ono K., Suzuki R.O. A new concept for producing Ti sponge: Calciothermic reduction. Journal of the Minerals Metals & Materials Society. 2002. 54: 59.
15. Karelin V.A., Strashko A.N., Dubrovin A.V. Electrolytic production of titanium powders in fluoride melts. Izvestiya Tomskogo politekhnicheskogo universiteta. (Bulletin of the Tomsk Polytechnic University). 2013. 323 (3): 82.
16. The Fact and FactSage databases.
17. Lebedev V.A., Sal’nikov V.I., Tarabaev M.V., Sizikov I.A., Rymkevich D.A. Compatibility of TiO2 with a CaO-CaCl2 melt. Russian Journal of Applied Chemistry. 2007. 80 (9): 1491.
18. Omel’chuk A.A., Gritsai L.V., Stezeryanskii E.A., Bosenko O.V. Effect of Composition of a Molten Electrolyte Mixture on Electrochemical Reduction of Zirconium Dioxide. Ukr.Khim. Zhurn. 2018.84. (12): 61.
19. Phase Identification from Powder Diffrac­tion (Match!). http://www.crystalimpact. com
20. GOST 2642.6-2017 Refractories and refractory raw materials. Methods for the determination of titanium oxide (IV). [in Russian]
21. Crystallographic program (Jana2006).
22. Crystallography Open Database.
23. Barbin N.M., Pekar’ A.P., Nekrasov V.N., Ivanovskij L.E. Solubility of alkali-earth metal oxides in molten equimolar NaCl-KCl mixture. Rasplavy (Melts). 1992. (2): 41.
24. Volkovich A.V. Interaction of alkali-earth metal oxides with equimolar potassium and sodium chloride mixture. Rasplavy (Melts). 1991. (4): 24.
25. Ukshe E.A. Free volume and equation of state of molten salts // In book: Physical chemistry of molten salts and slags. (Leningrad: Chemistry, 1968). [in Russian].
26. Novikov G.I. Fundamentals of General Chemistry. (Moscow: Higher school, 1988). [in Russian].
27. Ryabin V.A., Ostroumova M.A., Sweet T.F. Thermodynamic properties of substances. Directory. (Leningrad: Chemistry, 1977). [in Russian].
28. Ihsan Barin. Thermochemical data of pure substances // 3. ed. In collab. with Gregor Platzki. (Weinheim; New York; Basel; Cambridge; Tokyo: VCH, 1995).


Download data is not yet available.