Method for co-production of industrial-grade potassium dihydrogen phosphate and feed-grade dicalcium phosphate from wet-process phosphoric acid

The invention relates to a method for co-production of industrial-grade potassium dihydrogen phosphate and feed-grade dicalcium phosphate from wet-process phosphoric acid and belongs to the technicalfield of chemical production. The technical problem to be solved by the invention is to provide the method for co-production of the industrial-grade potassium dihydrogen phosphate and the feed-grade dicalcium phosphate from wet-process phosphoric acid. The method includes a) subjecting the wet-process phosphoric acid to extraction with an extractant to obtain an organic phase I and a water phase I; b) subjecting the organic phase I and a stripping agent to back extraction to obtain an organic phase II and a water phase II; c) purifying the water phase II to obtain an industrial-grade potassiumdihydrogen phosphate product; d) neutralizing the water phase I with a first neutralization agent and performing solid-liquid separation to obtain filter cake I and a filtrate I; e) neutralizing thefiltrate I with a second ne