Method for production of granular calcium dihydrogen phosphate by one-time granulation of concentrated phosphoric acid

Relating to the technical field of production of feed grade calcium dihydrogen phosphate, the invention discloses a method for production of feed grade granular calcium dihydrogen phosphate from wet-process defluorinated concentrated phosphoric acid. The method includes the steps of: S1: subjecting concentrated phosphoric acid with a phosphorus pentoxide content of 45-55wt% and a calcium carbonateemulsion to mixed reaction in a reactor to produce a mixed slurry containing calcium dihydrogen phosphate, wherein the calcium carbonate emulsion and concentrated phosphoric acid are proportioned according to a Ca/P ratio of 0.58-0.68, the reaction temperature is 60-80DEG C, the stirring speed of the reactor is 80-120 rpm, and the reaction time is 3-5min; S2: feeding the mixture slurry produced in S1 and the returned material together into a mixing granulator continuously for granulation so as to produce feed grade granular calcium dihydrogen phosphate wet semi-finished product; S3: sending the feed grade granular ca