Method for production of potassium sulfate from industrial by-product ammonium sulfate

The invention discloses a method for production of potassium sulfate from industrial by-product ammonium sulfate. The method directly uses the industrial by-product ammonium sulfate as the raw material to prepare potassium sulfate with potassium chloride by means of thermal double decomposition, wherein the industrial by-product ammonium sulfate contains a small amount of organic impurities and is obtained as a by-product generated in preparation of organic acid or ester compound by employing an organic nitrile compound or amide compound as the raw material and using sulfuric acid as the catalyst. According to the method provided by the invention, in a heating process of the raw materials, organic impurities in ammonium sulfate can burn and be removed. At the same time, the reaction system utilizes the heat released by organic impurities during burning to promote the thermal double decomposition reaction of ammonium sulfate and potassium chloride, thus reducing energy consumption of the preparation process. A