GB916550A - Method of preparing zirconium phospate - Google Patents

Abstract

Zirconium phosphate is prepared by reacting a solution of ammonium zirconium carbonate complex, or an alkyl ammonium zirconium carbonate complex with a solution of an ammonium phosphate, an alkyl ammonium phosphate, or a phosphoric acid. During the reaction carbon dioxide and ammonia or an alkyl amine (boiling point less than 100 DEG C.) are removed from the solution preferably by heating and aerating the solution; this evaporation produces gelatinous zirconium phosphate, which by further evaporation and drying, e.g. in a drying chamber, gives an amorphous vitreous substance or hard grains. This substance may be treated with water or preferably a strong acid such as hydrochloric acid, to give a granulate, which after washing with acid and water, and drying is suitable as an ion exchange material. The material may be graded by sifting, and unsuitable zirconium phosphate dissolved in ammonium carbonate solution and reprecipitated by evaporation. In the example ZrOCl2 solution is poured into an ammonium carbonate solution and the mixture stirred at 80 DEG C. To this solution is added a solution of (NH4)2HPO4. A strong stream of air is passed through the mixture at 80 DEG C., whereby a thick jelly of zirconium phosphate is obtained. This is poured into dishes and dried at 105 DEG C. and washed with five litres of 4N hydrochloric acid; the powdery product thus obtained is washed with 4N hydrochloric acid and deionized water until the washing has a pH of 4, dried at 80 DEG to 100 DEG C., and screened. In the above described process the ammonium carbonate used could be substituted by an alkyl ammonium carbonate, e.g. trimethyl ammonium carbonate.