Patent ID: 8852543

Claim:
A method of producing a crystalline anhydrous lanthanum oxycarbonate comprising: (a) reacting lanthanum chloride in a solution with sodium carbonate at a temperature of 30 to 90 degrees centigrade to form a precipitate; (b) recovering the precipitate and washing and drying the precipitate; and (c) thermally treating the precipitate of step (b) at a temperature of 400 to 700 degrees centigrade to produce the crystalline anhydrous lanthanum oxycarbonate; wherein said crystalline anhydrous lanthanum oxycarbonate is in the form of particles having a porous structure and having a BET specific surface area of at least about 10 m 2 /g or more, and wherein the crystalline anhydrous lanthanum oxycarbonate is selected from the group consisting of crystalline anhydrous La 2 O 2 CO 3 , crystalline anhydrous La 2 CO 5 , and a combination thereof.