Center of Earth Sciences, Metallurgy and Ore Benefication JSC (Republic of Kazakhstan):

Kovzalenko V. А., Ph. D. in Engineering Sciences, Leading Researcher, kovza40@mail.ru

Sadykov N. M.-K., Researcher, namad2003@mail.ru

Abdulvaliev R. A., Ph. D. in Engineering Sciences, Head of Laboratory, rin-abd@mail.ru

Institute of Geology and Nature Management, Amur Scientific Center, Far Eastern Branch of the Russian Academy of Sciences (Russia)

Rimkevich V. S., Ph. D. in Geology and Mineralogy, Head of Laboratory, vrimk@mail.ru

A combination technology for high-silica raw material treatment by means of fluoride method is presented, and the process conditions are determined for production of ammonium hexafluorosilicate, amorphous silica, aluminium fluorine compounds and ferrous concentrate. The process of raw material and ammonium bifluoride sintering, providing for sinter mix separation into gas-phase as ammonium hexafluorosilicate and aluminium nonvolatile fluorine compounds and iron, concentrated in sinter solid phase, was investigated. The optimal sintering process conditions were established: the ratio of high-silica raw material and ammonium bifluoride, step-up process temperature increase, duration. It was determined, that with interaction of ammonium hexafluorosilicate and ammonium solutions, amorphous silica is formed. Mother solution, following precipitation of amorphous silica, is subjected to isothermal crystallization through concentration by evaporation with a view to regeneration of ammonium bifluoride. In the pyro-hydrolysis process, with heating of sinter, upon water steam and temperature effect, metal fluorides pass into metal-oxides and sublimation separation of fluoride with formation of fluorohydrogen acid is accomplished. In order to separate aluminium and iron oxides in concentrate, autoclave-alkali-solution leaching is applied, producing alkali-aluminate solution and ferrous concentrate. Alkalialuminate solution interaction with fluorohydrogen acid solution produces cryolite, used in metallic aluminum electrolysis.

1. Kovzalenko V. A., Sadykov N. M.-K., Myltykbayeva L. A., Abdulvalieyv R. A., Gladyshev S. V., Pozmogov V. A. Complex processing of quartz ore by fluoride method. Kompleksnoye ispolzovanie mineralnogo syr'ya = Complex Use of Mineral Resources, 2013, No. 2, pp. 29–37.
2. Kovzalenko V. A., Sadykov N. M.-K., Myltykbayeva L. A., Abdulvaliyev R. A., Gladyshev S. V., Pozmogov V. A. Fluoride method for obtaining amorphous silica. Kompleksnoye ispolzovanie mineralnogo syr'ya = Complex Use of Mineral Resources, 2013, No. 4, pp. 41–46.
3. Rimkevich V. S., Pushkin A. A., Malovitsky Yu. N., Yeranskaya T. Yu., Girenko I. V. Complex processing of kaolin concentrates by fluoride metallurgy. Izvestiya VUZ. Tsvetnaya Metallurgiya = Russian Journal of Non-Ferrous Metals, 2010, No. 2, pp. 29–36.
4. Lataste E., Legein C., Body M., Buzaré J.-Y., Tressaud A., Demourgues A. Highly fluorinated silica obtained by direct F2-gas fluorination: stability and unprecedented fluorosilicate species revealed by solid state NMR investigations. J. Phys. Chem. C, 2009, Vol. 113, Iss. 43, pp. 18652–18660.
5. Demyanova L. P., Tressaud A., Labrugere C., Durand E., Majimel J., Petsyk P. A., Kozlov K. G. Fluorination of nanosized amorphous silica derived from silicate raw materials. Fluorine Notes, 2012, Vol. 3 (82).
6. Innovation pat. 26588 Republic of Kazakhstan.
7. Dem’yanova L. P., Buynovskiy A. S., Rimkevich V. S., Malovitskiy Yu. N. Rational processing of quartz-bearing raw material by fluoride method. Izvestiya Tomskogo Politekhnicheskogo Universiteta = Bulletin of the Tomsk Polytechnic University, 2010, Vol. 317, No. 3, pp. 77–81.
8. Tressaud A., Labrugère C., Demyanova L. P., Durand E., Serier H. Surface modification of phyllosilicate minerals by fluorination methods. J. Vac. Sci. Technol. A, 2010, Vol. 28, Iss. 2, pp. 373–381.
9. Dem’yanova L. Ftoridnyy sposob pererabotki kvartssyr'ya s polucheniyem chistykh produktov (Fluoride raw quartz processing method to obtain pure products). Berlin, Lambert Academic Publishing, 2011, 118 p.
10. Dem'yanova L. P., Makeeva T. B., Buinovskii A. S. Structural and phase changes in natural quartz crystal upon fluoride treatment. Steklo i Keramika = Glass and Ceramics, 2011, No. 11, pp. 32–35.
11. Rimkevich V. S., Dem'yanova L. P., Sorokin A. P. Comprehensive utilization of silica raw material of the Upper and Mid-Amur river basin. Fiziko-Tehnicheskiye Problemy Razrabotki Poleznykh Iskopayemykh = Journal of Mining Sciences, 2011, No. 4, pp. 106–116.
12. Demyanova L. P., Tressaud A. Fluorination of alumino-silicate minerals: the example of lepidolite. Journal of Fluorine Chemistry, 2009, Vol. 130, Iss. 9, pp. 799–805.