Formation of ion-exchanging precipitates of hydrated niobium (5) pentoxide in medium of ferrocyanide -and polyvanadate-ions

The effect of the chemical nature of sorbable anionic additives and also of the concentration of polyvanadate and ferrocyanide ions in the phase of hydrated niobium pentoxide (HNP) on its sorption-specific properties was investigated. The isotherms of sorption of bichromate and polyvanadate ions by the HNP specimens in a medium of additives of different concentration are calculated. The relationship of the exchange capacity of HNP with the processes of condensation curing of the matrix and peptization phenomena developing in it in the course of alkaline treatment is demonstrated. The possibility of washout of ferrocyanide and polyvanadate additives by ammonia solutions is studied