METHOD AND DEVICE FOR RESOURCEFUL TREATMENT OF INDUSTRIAL WASTE SALT

摘要

Provided are a method and a device for the resourceful treatment of an industrial waste salt. The method comprises the following steps: subjecting the industrial waste salt to dissolution, chemical pre-impurity-removal, deep impurity removal, organic matter concentration and reduction, adsorptive and oxidative decolorization and multi-effect evaporation and crystallization successively to obtain sodium sulfate, sodium chloride and sodium nitrate crystals, respectively, wherein the crystallization temperature of sodium sulfate is 75-85ºC; the crystallization temperature of sodium chloride is 60-70ºC; and the crystallization temperature of sodium nitrate is 45-55ºC. In the present method, organic matter and other impurities in the industrial waste salt are firstly removed, and then, using the difference of the co-saturation point of three phases of the sodium chloride, sodium nitrate and sodium sulfate at different temperatures and the solubility of the salts, the salts are separated and crystallized by controlling the temperature during the evaporation, and the purity and whiteness of the obtained sodium chloride, sodium nitrate and sodium sulfate all reach an industrial standard, and same can be directly used.