Fluoroammonium technology of zircon processing

In Tomsk Polytechnic University there was suggested and then patented method of zircon autoclave opening with the help of ammonium fluoride. The use of ammonium fluoride for opening of Tugan zircon, as well as possibility of its regeneration and return into the process allow to set up manufacture of zirconium products facing present-day ecological requirements.

According to suggested and patented method zircon is mixed with ammonium fluoride and heat; the result is a composition of zirconium fluoride, ammonium fluosilicate, ammonia and water.After getting zirconium tetrafluoride it is easy to regenerate ammonium fluoride by means of ammonia water out of it.

ZrSiO4 4 + 13NH4F = (NH4)3ZrF7 + (NH4)2SiF6 + 8NH3 + 4H2O

An important advantage of ammonium fluoride use is the possibility to separate silicic constituent of zircon in the form of ammonium hexafluosilicate (NH4)2SiF6. Ammonium fluoride can be regenerated from ammonium hexafluosilicate and silicon can be extracted in the form of silicon oxide of the sort named “white black”.

According to the results of experimental researches there was suggested a technological scheme of zircon decomposition by ammonium fluoride with return into cycle NH4F. Zircon does not actively react with ammonium fluoride under atmospheric pressure, while totally decomposes in autoclave under pressure of 30 atm.

End product of zircon processing is microfiber zirconium dioxide. Microfibers of zirconium dioxide can be applied in the following areas:

1) reinforcing additive to composition materials

2) formation of light-weight zirconium

Simplicity of this scheme and its realization in laboratory allows to speak with confidence about its introduction into industry.

The use of zirconium dioxide as additives and refractory materials is becoming much more in demand in the world markets. At the same time in the world there exist no techniques of microfiber zirconium dioxide large-capacity getting. Below there are given comparative microphotographs of zirconium dioxide obtained by plasmachemical technology (a) and microfiber zirconium dioxide obtained in Tomsk Polytechnic University (b).

The price for development of technical report for manufacturing complex design amounts 150 000. Type of relations is an agreement with Tomsk Polytechnic University.