The invention discloses a high-yield hydrated crystalline
phase reconstruction wet-process
phosphoric acid production technology. The technology comprises a semi-hydrated reaction
filtration process and a dihydrate reaction
filtration process, and the semi-hydrated reaction
filtration process comprises the steps of premixing, dissolving, crystallizing, curing and semi-hydrated filtration; and the dihydrate reaction filtration process comprises a conversion step and a dihydrate filtering step. According to the invention, through gradient control of the relationship between the
sulfate ion concentration and the CaO concentration in different stages of the semi-hydrated reaction, the
crystal size is increased, the
crystal is kept stable, and the semi-hydrated
gypsum crystal with uniform particle size is obtained; by changing the circulation path of the
slurry, the reaction
retention time is prolonged, and the growth of semi-hydrated
gypsum crystals in a relatively stable environment is ensured; coarse, uniform and stable dihydrate
gypsum crystals are obtained by controlling the degree of
supersaturation of a dihydrate reaction, the filtering performance is good, the content of water-soluble
phosphorus in the dihydrate gypsum is reduced, and the filtering yield is improved; and by reasonably utilizing the filtrate and the flushing water, the
wastewater discharge is reduced, and the total yield of P2O5 is increased.