Method for preparing modified light calcium carbonate from phosphogypsum

The invention discloses a method for preparing modified light calcium carbonate from phosphogypsum. The method comprises the following steps: dissolving ardealite in an ammonium lactate solution, filtering to obtain a calcium-rich solution, carbonizing with ammonium carbonate to obtain light calcium carbonate, carrying out wet surface modification on the light calcium carbonate by using a modifier compounded from vinyl carboxylate, carbon nitride and vitamin E polyethylene glycol succinate, and drying to obtain the light calcium carbonate. A stable macromolecular organic hydrophobic coating layer is formed on the surface of the light calcium carbonate, the lipophilicity of the surface of the light calcium carbonate is increased, the compatibility with resin is better, the PP material is filled with the prepared modified light calcium carbonate, the heat resistance, impact resistance and bending resistance of the PP material can be remarkably enhanced, and the preparation method is simple in process, low in pr