Preparation of titanium(IV) phosphates

This paper shows the results of investigation of titanium(IV) phosphates precipitation from acidic solution of titanyl sulfate. In investigation was used the titanyl sulfate solution obtained as the product of decomposition of ilmenite by sulfuric acid during production of titanium dioxide white pigments. The titanium(IV) phosphates were precipitated by the action of orthophosphoric acid, at different acid concentration. It has been found that precipitation of titanium phosphates occurs at phosphoric acid concentration range from 5 to 80 wt%. The prepared materials were analysed using chemical, thermogravimetric and X-ray diffractometric methods. It has been established that freshly precipitated titanium phosphates are practically amorphous. During their thermal treatment are formed crystalline products which, in dependence on used phosphoric acid concentration, are composed of titanium pyrophosphate, TiP2O7 or mixture of titanium pyrophosphate and titanium oxide biphosphate, Ti2O(PO4)2