According to the situation that the conventional reaction kettle is easy to be damaged and its production efficiency and mixing effect are limited, we have specifically developed the external kettle recycle system installation ( having been applied for state patent). with this technique adopted, the production efficiency can be elevated by above 2 times and the service life of the ceramic kettle can be prolonged by 3 times. Moreover, the mechanical mixing can be done away with, and the hermetically sealed production be conducted, the leakage of detrimental gas being eliminated. .