Abstract: Food grade and high purity phosphoric acid crystals were prepared by batch cooling crystallization with industrial grade purified wet-process phosphoric acid as raw material.The influences of  stirring rate，cooling rate，growth substance dosage，and crystallization time on the purification effect of phosphoric acid crystallization were investigated，and the optimum conditions were confirmed as follows: stirring speed of 400 r/min，cooling rate of 4 ℃/h，growth substance dosage of 0.15%~0.2%，and crystallization time of 1.5 h.Under the optimum conditions，the prepared products reached the quality requirements of food grade and above，stipulated in the Standard of Food Additive Phosphoric Acid（GB 3149—2004），and their added value was higher.The method provides a new way for the industrial production of high-quality phosphoric acid by purification of wet process phosphoric acid.

Key words: purified wet-process phosphoric acid, crystallization, phosphoric acid crystal, purification