Mutual influence of ammonium hexafluorotitanate and hexafluorosilicate in ammonium fluoride solutions

Conditions for the hydrolysis of a titanium salt without adding alkaline reagents arise in the system (NH(4))(2)TiF(6)-(NH(4))(2)SiF(6)-NH(4)F-H(2)O. The hydrolysis is caused by a more alkaline pH of the (NH(4))(2)SiF(6) solution in the presence of NH(4)F as compared to the pH of the (NH(4))(2)TiF(6) hydrolysis beginning in a solution of NH(4)F of the same concentration. In the bottom phase isolated from the above system at 25A degrees C, (NH(4))2SiF(6) is identified not in the cryptohalite form corresponding to the modification of the initial silicon salt, but in the bararite form. This transfer is caused by the isovalent isomorphous substitution of Si(+4) ions for Ti(+4) in the complex TiF (6) (2-) .