1. Calcined with calcium superphosphate, defluorinated and desulfurized, cooled, crushed and sieved to 180 mesh, and the feed calcium phosphate was obtained.

2. The sodium phosphate solution reacts with a proper amount of calcium chloride saturated solution in the presence of excessive ammonia to precipitate insoluble calcium phosphate, and the finished product of calcium phosphate is obtained after filtration, washing and drying.

3. Saturated lime milk solution reacts with hot concentrated phosphoric acid above pH 8. 1 to generate tricalcium phosphate precipitate.