Technology for preparation of dihydrate gypsum by recycling of filter press fluorine waste residue

The invention relates to a technology for preparation of dihydrate gypsum by recycling of filter press fluorine waste residue. The technology includes the steps of: weighing raw materials according to the weight percentage: 20%-40% of dry process gypsum, 40-60% of wet gypsum, 15%-25% of filter press residue, and 0.5%-1.5% a composite admixture; mixing the dry process gypsum with the filter press residue evenly in proportion; adding the well mixed materials, the wet gypsum and the composite admixture into a mixing breaking machine, and controlling the particle size of the mixed and broken material not greater than 100mm; conducting aging and hydration: stockpiling the material for 48-96h, thus obtaining the dihydrate gypsum. The product produced by the invention has a SO3 content of over 38%, a crystal water content of over 8% above, and an attached water content within 12%. The dihydrate gypsum contains a small amount of attached water, almost does not generate dust during use, and is non-acidic, thus belongi