Interaction in iron(2) sulfate-potassium hexatantalate-water system

Interaction in the iron(2) sulphate-potassium hexatantalate-water system has been studied. It has been found that at a mole ratio of the reacting components equal to 1.5 iron (2) hexatantalate is formed. Due to partial oxidation, the precipitate in an air-dry state has FeOx1.5Fe2O3x3Ta2O5x18H2O composition. Its properties have been studied by roentgenographic, thermographic, thermogravimetric, and infrared spectroscopic methods. It has been established that dehydration is accompanied by rearrangement of the structure with the formation of tapiolite and tantalum pentoxide phases