由含硫酸钠的废液直接制无水硫酸钠

Direct Preparation of Anhydrous Sodium Sulfate from Waste Liquid containing Sodium Sulfate

采用蒸发结晶的方法从含硫酸钠的废液中直接结晶出无水硫酸钠。该方法与先制芒硝，再由芒硝制无水硫酸钠的方法相比，具有工艺流程短、设备少、投资省、能耗低和成本低等优点。研究了不同的蒸发结晶、过滤、洗涤等条件对产品质量的影响。制得了符合国家标准（GB6009－85）要求的一级品无水硫酸钠。

Anhydrous sodium sulfate has been directly prepared from the waste liquid containing sodium sulfate by evaporation-crystalization process. Compared with the method via first preparation mirabilite, the direct preparation has the advantages of shorter process flow, fewer equipment, less investment, lower energy consumption and lower cost. The influence of different conditions of evaporation, crystalization, filtration and washing on the quality of product has been studied. The product can meet the first-grade of sodium sulfate set in the natinal standard (GB6009-85).