关键词: 分析纯元明粉, 控制pH, 硫酸钠

Abstract: The production of analytical grade sodium sulfate，which matches GB/T 9853—2008，by using 90% sodium sulfate（the semi-finished wet products collected from centrifuge） obtained from the general process as raw material has been presented.The procedures generally include dissolution，pH adjusting，evaporation，separation，and drying etc..The main central parameters are that the solution pH must be between 3~6，and the terminal control point in evaporation requires that the concentration of Ca2+ ions within the mother liquor must be no more than 0.55 g/L.It is assumed that the as-prepared analytical grade sodium sulfate products are of high solubility，high purity，and stable quality.Moreover，the process is also of great advantages of simple，low cost，and high profit，which promise it expansive potentials.

Key words: analytical grade sodium sulfate, pH controlling, sodium sulfate