Method for purifying titanium white wastewater

The invention relates to a method for purifying titanium white wastewater, which is characterized by comprising the following steps of: adding excess lime milk or carbide slag slurry, performing a neutralization reaction with stirring to obtain precipitate-containing wastewater, wherein the pH value of the wastewater is between 9 and 12; performing solid-liquid separation on the obtained precipitate-containing wastewater, adding sodium carbonate into filter liquor to perform a reaction for 30 to 50 minutes, and adding trisodium phosphate to perform a reaction, and decalcifying; adding sulfuric acid into the decalcified wastewater for reverse neutralization, and regulating the pH value to be between 6 and 9 to obtain purified water. The method has the characteristics of simple flow, no specific requirement on equipment, low consumption of raw materials and the like; and by the method, the treated wastewater can reach the technical standard of national recycling water, so that the wastewater is recycled to prod