The invention belongs to the technical field of reusing of salt chemical wastes, and discloses a process for preparing high-strength
gypsum from salt chemical wastes. The process for preparing the high-strength
gypsum from salt chemical wastes comprises the following steps: step 1, mixing a
calcium chloride solution with old brine and stirring to obtain mixed
slurry of
sodium chloride and dihydrate
gypsum; step 2, desalting and washing the mixed
slurry to obtain purified dihydrate gypsum
slurry; step 3, regulating the dihydrate gypsum slurry to be acidic, adding an activity agent and a crystalmodifier, and preparing alpha-
hemihydrate gypsum by a normal-pressure hydrothermal method; step 4, carrying out
solid-liquid separation; step 5, carrying out desalting, acid removal and washing; andstep 6,
drying to obtain the high-strength gypsum finished product. The process for preparing the high-strength gypsum from the salt chemical wastes has the beneficial effects that active growth of the intermediate dihydrate gypsum crystals is controlled effectively, and the strength of the high-strength gypsum is improved; the normal-pressure hydrothermal method is adopted,
energy consumption islow, investments are low, and a
crystal form is easy to control; and the problem of
solid wastes is solved effectively, and the requirements of industrial and green
sustainable development are met.