Fluorination of titanomagnetite concentrate with ammonium bifluoride

Objectives. To study the technological features of a new fluoride technology for the production of titanium dioxide by the decomposition of titanomagnetite concentrate with ammonium fluorides.

Methods. The chemical species of the titanium and iron components in the fluorination of titanomagnetite concentrate and sublimation separation of components were determined by means of X-ray powder diffraction analysis and inductively coupled plasma mass spectrometry. The kinetics of sublimation of the titanium component by the thermal decomposition of ammonium hexafluorotitanate was experimentally studied.

Results. The products of the fluorination of titanomagnetite concentrate with ammonium bifluoride are compounds (NH₄)₂TiF₆ and (NH₄)₃FeF₆, as proven by chemical analysis and X-ray powder diffraction analysis. The subsequent sublimation separation of the titanium component produced the target product: a mixture of ammonium fluorotitanates. The desublimation of the titanium-containing fraction gave an NH₄TiF₅–(NH₄)₂TiF₆–(NH₄)₃TiF₇ mixture, the titanium content of which is 30.6% and the content of impurities (Fe, V, Si) is a minimum (0.45%). The activation energy of the heterogeneous reaction and the rate-limiting step of the process were also determined.

Conclusions. A high-purity titanium product (a mixture of ammonium fluorotitanates) is obtained. This is a valuable commercial product for the industrial production of titanium dioxide pigment from titanomagnetite concentrate and ilmenite.

1. Dyachenko A.N., Dyachenko E.N., Kraidenko R.I. Titanium dioxide: market, production, new technologies. Lakokrasochnye materialy i ikh primenenie = Russ. Coating J. 2021;(7–8):41–50 (in Russ.).

2. Fomina N.N., Ismagilov A.R., Fomin V.G. Titanium pigment dioxide dispersity. Stroitel’stvo i rekonstruktsiya = Building and Reconstruction. 2020;(2):136–142 (in Russ.).

3. Pavlunenko L.E., Guba L.N. Characterization of the properties of titanium pigments for paints and varnishes. Stroitel’stvo i tekhnogennaya bezopasnost’ = Construction and Industrial Safety. 2013;(46):56–62 (in Russ.).

4. Rakov E.G., Mel’nichenko E.I. The Properties and Reactions of Ammonium Fluorides. Russ. Chem. Rev. 1984;53(9):851–869. https://doi.org/10.1070/rc1984v053n09abeh003126 [Original Russian Text: Rakov E.G., Mel’nichenko E.I. The Properties and Reactions of Ammonium Fluorides. Uspekhi Khimii. 1984;53(9):1463–1492 (in Russ.).]

5. Dyachenko A.N. Method for Producing Titanium Dioxide from Ilmenite: RF Pat. 2770576. Publ. 04.18.2022.

6. Kraidenko R.I., Kantaev A.S., Lashtur A.L. Method for Obtaining Titanium Dioxide of Rutile Modification: RF Pat. 2643555. Publ. 02.02.2018.

7. Dmitriev A.N., Smorokov A.A., Kantaev A.S., Nikitin D.S., Vit’kina G.Yu. Fluoroammonium method of titanium slag processing. Izvestiya vuzov. Chernaya metallurgiya = Izvestiya. Ferrous Metallurgy. 20214;64(3):178–183 (in Russ.). https://doi.org/10.17073/0368-0797-2021-3-178-183

8. Smorokov A.A., Kantaev A.S., Bryankin D.V., Miklashevich A.A. Development of a low-temperature desiliconization method for the leucoxene concentrate of the Yarega deposit with a solution of ammonium hydrogen fluoride. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. = ChemChemTech. 2022;65(2):127−133 (in Russ.). https://doi.org/10.6060/ivkkt.20226502.6551

9. Gordienko, P.S., Pashnina, E.V., Bulanova, S.B., et al. Preparation of Titanium Dioxide from the Ammonium Hexafluorotitanate–Silicon Dioxide System. Theor. Found. Chem. Eng. 2022;56(5):819–829. https://doi.org/10.1134/S0040579522050062 [Original Russian Text: Gordienko P.S., Pashnina E.V., Bulanova S.B., Dostovalov D.V., Kuryavyi V.G., Shabalin I.A., Karabtsov A.A. Khimicheskaya tekhnologiya. Production of titanium dioxide from the ammonium hexafluorotitanate – silicon dioxide system. Khimicheskaya Tekhnologiya. 2021;22(12):530–542 (in Russ.).]

10. Mel’nichenko E.I., Epov D.G., Krysenko G.F. Ammonium oxofluorotitanates. Russ. J. Inorg. Chem. 2002;47(2):155–158.

11. Mel’nichenko E.I., Krysenko G.F., Epov D.G., Rakov E.G. Titanium oxyfluorides. Russ. J. Inorg. Chem. 2001;46(12):1769–1774.

12. Laptash N.M., Maslennikova I.G. Fluoride processing of titanium-containing minerals. Adv. Mater. Phys. Chem. 2013;2(4):21–24. http://dx.doi.org/10.4236/ampc.2012.24B006

13. Habashi F. Kinetics of Metallurgical Processes. Sainte Foy, Québec City: Métallurgie Extractive Québec, distributed by Laval University Bookstore; 1999. ISBN 2-980-3247-6-0. URL: https://works.bepress.com/fathi_habashi/5/. Accessed October 10, 2023.