Patent ID: 8425871

Claim:
A method of synthesizing yttrium phosphate compounds comprising: (a) producing the yttrium phosphate compounds by a process consisting of the steps of: (i) forming an aqueous slurry of a relatively insoluble yttrium compound; (ii) adding phosphoric acid to the slurry to form the yttrium phosphate compounds, the amount of phosphoric acid added being less than the stoichiometric amount needed to convert all of the yttrium compound to the yttrium phosphate compounds, wherein the slurry is maintained at a temperature between about 20° C. and about 70° C.; and (iii) adding an inorganic acid to the slurry which forms a water soluble salt with yttrium; and (b) isolating the yttrium phosphate compounds by separating the slurry into solid yttrium phosphate compounds and an aqueous phase.