摘要 |
A process for modifying dihydrate gypsum, comprising:
a calcination step of subjecting the dihydrate gypsum as a starting raw material to calcination to convert the dihydrate gypsum into hemihydrate gypsum,
a recrystallization step comprising forming the obtained hemihydrate gypsum into a slurry in the presence of a surfactant and/or a defoaming agent, and hydrating and recrystallizing the hemihydrate gypsum in the presence of the surfactant and/or the defoaming agent into dihydrate gypsum, and
a step of separating, from a slurry after completion of the recrystallization step, the modified dihydrate gypsum by an elutriation method. |