Preparation of dilute solutions of rare earth metal trichlorides by chlorination of their oxides in a molten NaCl-KCl equimolar mixture

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Аннотация

The article is devoted to the study and thermodynamic justification of the method for obtaining dilute solutions of rare earth metal trichlorides by chlorination of their oxides in a molten equimolar mixture of NaCl – KCl. And the effectiveness of this method is demonstrated by the example of lanthanum (III) and neodymium (III) oxides. Gibbs free energy of the reactions of La2O3 and Nd2O3 chlorination by different chlorinating agents has been calculated. The interaction of lanthanum (III) and neodymium (III) oxides in the molten equimolar mixture NaCl – KCl depending on the chlorination time and the material of reaction vessel (beryllium oxide and glass-carbon) has been studied experimentally. The results of thermodynamic modelling of the chlorination reactions of La2O3 and Nd2O3 by gaseous chlorine in this salt melt are presented. In the case of using a molten equimolar mixture of NaCl – KCl, a significant shift of the Gibbs energy to the negative region is observed compared with chlorination without the use of a salt medium. The effectiveness of chlorine as a chlorinating agent in the melt is based on the fact that in liquid NaCl-KCl Ln3+ ions form complexes with very small activity coefficient. The removal of synthesized lanthanum trichloride from the chlorination reaction zone due to its solubility in a low-viscosity NaCl-KCl melt has a beneficial effect on the rate of its flow. It has been shown that the formation of rare earth metal trichlorides occurs through the formation of LaOCl and NdOCl oxychlorides. The advantages of the proposed method of chlorination of rare earth metal oxides (REM) in the synthesis of solutions of their trichlorides in molten salts are shown.

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Авторлар туралы

A. Kolobov

AO “DINUR”; Institute of High Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences

Хат алмасуға жауапты Автор.
Email: art.kolobov@yandex.ru
Ресей, Pervouralsk; Yekaterinburg

A. Potapov

Institute of High Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences

Email: art.kolobov@yandex.ru
Ресей, Yekaterinburg

V. Khokhlov

Institute of High Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences

Email: art.kolobov@yandex.ru
Ресей, Yekaterinburg

Әдебиет тізімі

  1. Revzin G.E. Anhydrous chlorides of rare earth elements and scandium. – In the collection: Methods of obtaining chemical reagents and preparations. M.: IREA. 1967. issue. 16. pp. 124–129.
  2. Taylor M.D. Preparation of anhydrous lanthanon halides. // Chem.Rev. 1962. 62. № 6. pp.503–511.
  3. Gmelin Handbook of Inorganic Chemistry. 8th Ed. Sc, Y, La-Lu Rare earth elements. Part C 4a. System Number 39. Berlin – Heidelberg – N.-Y. Springer, 1982.
  4. Laptev D.M. Physico-chemical properties of lanthanide chlorides and their interaction in LnCl3 – LnCl2 systems. Dis. ... doctor of Chemical Sciences. Siberian State Mining and Metallurgical Academy named after S. Ordzhonikidze. Novokuznetsk, 1996. 394 p.
  5. Morozov I.S., Korshunov B.G. Interaction of neodymium and lanthanum oxides with chlorine gas // Journal of Inorganic Chemistry. 1956. No. 1. pp. 2606–2612.
  6. Morozov I.S., Korshunov B.G. On the thermodynamics of chlorination of rare earth metal oxides with chlorine gas // Reports of the USSR Academy of Sciences. 1958. Volume 119. No. 3. pp. 523–525.
  7. Senderoff S., Mellors G. W., Bretz R. I. Thermodynamic properties of solutions of cerium chloride in molten alkali halides. Annals New York Academy of Science 1960. 79. pp.878–896.
  8. Bagri P., Bastos T., Simpson M.F. Electrochemical methods for determination of activity coefficients of lanthanides in molten salts. ECS Transactions. 2016. 75. № 15, pp.489–495.
  9. Novoselova A.V., Smolenskii V.V. Electrochemical and thermodynamic properties of lanthanides (Nd, Sm, Eu, Tm, Yb) in alkali metal chloride melts. Radiochemistry. 2013. 55. № 3. pp. 243–256.
  10. Volkovich B. A., Medvedev E. O., Vasin B. D., etc. Spectroscopic investigation of the chlorination of lanthanide oxides in alkali metal chloride melts // Melts. 2006. No. 5. pp. 21–28.
  11. Khokhryakov A.A., Mikhaleva M.V., Molchanov A.M. //Journal of Inorganic Chemistry. Electronic absorption spectra of molecular chlorine solutions in molten alkali metal chlorides 2007. Vol. 52. No. 10. pp. 1705–1708.
  12. Kolobov A., Khokhlov V., Potapov A., Kochedykov V. Chlorine solutions in molten alkali chlorides. // Z.Naturforsch. 2007. 62a. № 3–4. P. 205–212.
  13. Bezukladnikov A.B., Baibakov D.P., Tarat E.Ya. // Trudy LTI im. Lensoveta, 1969. pp. 112–114.
  14. Baibakov D. P. Dis. ... candidate of Technical Sciences. LTI named after the Lensovet. Leningrad. 1971. – 144 p..
  15. Kolobov A.Yu., Potapov A.M., Khokhlov V.A. Chlorination of neodymium and lanthanum oxides with chlorine gas in a molten equimolar mixture NaCl – KCl. – In the collection: Demidov readings in the Urals, abstracts of reports Yekaterinburg, 2006. pp. 167–168.
  16. Smirnov M.B., Palguev C.F., Ivanovsky L.E. // J. Phys. Chemistry. Chlorine reference electrode in molten chlorides. 1966. 29. No. 5. pp. 772–777.
  17. Serebrennikov B.B. Chemistry of rare earth elements, vol. 1, Tomsk: Publishing House of the Tomsk University. 1959. 533 p.
  18. Kochedykov B.A., Zakiryanova I.D., Akashev L.A. Identification of products of interaction of rare earth metal oxides with air components by IR spectroscopy. Analytics and control. 2006. Volume 10. No. 2. pp.172–174.
  19. Kochedykov B.A., Zakiryanova I.D., Korzun I.B. Investigation of thermal decomposition of products of interaction of REE oxides with components of the air atmosphere. Analytics and Control. 2005. Volume 9. No. 1, pp.58–63.
  20. I.S. Morozov, Using of chlorine in the metallurgy of rare and non-ferrous metals, Nauka, Moscow, 1966
  21. S.L. Stefanyuk and I.S.Morozov, Zhur. Prikl. Khim. 38, 729. 1965.
  22. J.J. Katz and E. Rabinowitch, The Chemistry of Uranium, McGraw-Hill Book Company, Inc., N.Y. – Toronto – London 1951.
  23. V.A. Volkovich, T.R.Griffits and R.C. Thied, Proc. Int. G. Papatheodorou Symp. Patras, Sept.17–18, 1999. FORTH-ICE/HT, Patras, Greece, 1999, p. 78.
  24. A. Roine. HSC Chemistry [Software], Outotec, Pori. – 2018. – URL: www.outotec.com/HSC.
  25. Repin C.A. Preparation of anhydrous chlorides of rare earth elements. In the collection of Rare Earth metals. Ed. Ryabchikov D.I. 1963. M.: Nauka, pp.71–74.
  26. Stoyanova M.I., Konakova B.A., Ivashentsev Ya.I. On the interaction of one and a half lanthanide oxides with carbon tetrachloride. Izv. Universities. Colormet. 1974. № 3, c.103–106.
  27. Binnewies, E. Milke, Thermochemical Data of Elements and Compounds, Wiley-VCH, Weinheim. 2002
  28. B.D. Vasin, V.A. Ivanov, A.V. Sheetinskii. Potentiometric study of lanthanum-containing melts based on an equimolar mixture of sodium and potassium chlorides // Rasplavy (Melts). № 4. 103. 2000.

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2. Fig. 1. ΔG(T) of La2O3 chlorination reactions with various chlorinating agents.

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3. 2. ΔG(T) of the chlorination reactions of Nd2O3 with various chlorinating agents.

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4. 3. An example of the kinetic calcination curve of the initial Ln2O3 and Nd2O3 samples.

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5. 4. Dependence of the degree of chlorination of lanthanum and neodymium oxide in a molten equimolar NaCl –KCl mixture on time at 700°C.

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6. 5. The equilibrium composition of the molten mixture (NaCl-KCl (1:1) + 5 kmol C + 1 kmol La2O3) with up to 6 kmol of chlorine passing through.

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7. 6. The equilibrium composition of the molten mixture (NaCl-KCl (1:1) + 5 kmol C + 1 kmol La2O3) when passing up to 6 kmol of chlorine with increasing scale along the vertical axis.

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8. 7. Equilibrium composition of the molten mixture (NaCl-KCl (1:1) + 5 kmol C + 1 kmol Nd2O3) with up to 6 kmol of chlorine passing through.

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9. 8. Equilibrium composition of the molten mixture (NaCl-KCl (1:1) + 5 kmol C + 1 kmol Nd2O3) when passing up to 6 kmol of chlorine with increasing scale along the vertical axis.

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10. 9. Gibbs energy of the reaction (1) of chlorination of lanthanum (III) and neodymium (III) oxides, according to thermodynamic data [27]. ∆G The La2O3 chlorination reactions in NaCl – KCl were calculated using the values of the formal standard potentials E*La(III)/La from [28].

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