The invention belongs to the technical field of clean production, and particularly relates to a
crystallization method for
aluminum fluoride production. The method comprises the steps of S1, reacting fluosilicic acid and aluminum
hydroxide in an anti-
corrosion storage tank to generate
aluminum fluoride-
silica gel slurry; S2, conveying the generated
aluminum fluoride-
silica gel slurry to a
belt filter through a filter pump, and separating an aluminum
fluoride supersaturated solution from
silica gel under the action of negative pressure pumping of a
vacuum pump, wherein the aluminum
fluoride supersaturated solution enters a
crystallization tank to generate aluminum
fluoride trihydrate crystals, and silica gel enters a
cryolite-containing silica gel synthesis tank; S3, introducing 90 DEG C steam into the aluminum fluoride supersaturated solution filtered by the silica gel in the
crystallization tank, and keeping for 4-6 hours to generate aluminum fluoride trihydrate crystals; and S4, putting the crystallized
solid-liquid mixture on a tilting-pan filter, separating aluminum
fluoride crystals from
mother liquor under the negative pressure pumping action of the
vacuum pump to obtain ointment, enabling the
mother liquor to flow into a
settling tank for
settling, treating
waste gas by using supernate, retaining precipitate crystals, scattering the crystallized ointment to enter, and
drying a first-section semi-finished product of aluminum fluoride. The crystallization effect is good.