采用冷却结晶和筛分法研究了响应曲面法设计下pH值、Fe3+浓度、搅拌速率各因素不同水平对平均粒径和变异系数影响程度, 构建了平均粒径2次回归模型和C·V·值2FI回归模型, 深入探究了各影响因素之间交互作用, 研究表明: 各因素对平均粒径和C·V·值影响程度为母液pH>搅拌速率>Fe3+质量浓度; 各因素之间交互作用对晶体平均粒径和C·V·值影响程度为AC >BC >AB; 当母液pH为5.5、搅拌速率为150 r/min、Fe3+质量浓度为0.3 g/L时, 可得到平均粒径为0.985 mm、C·V·为793.719的晶体; 经验证模型值与实验值误差较小, 回归模型具有良好拟合度和可靠性。

The influences of pH value, Fe3+ mass concentration, and stirring rate and their interactions on the ammonium sulfate crystallization were investigated via cooling crystallization and sieving based on a response surface methodology. An average particle size quadratic orthogonal model and a variation coefficient 2FI orthogonal model were proposed. The interactions among the various factors were analyzed. The results show that pH value (A) > stirring rate (C) > Fe3+ ions concentration (B) is a decreased order for the parameter effects on the average particle size and variation coefficient. Their interactions have a decreased effect order (i.e., AC > BC > AB) on the average particle size and variation coefficient. When pH value is 5.5, stirring rate is 150 r/min, and Fe3+ ions concentration is 0.3 g/L, the average particle size and variation coefficient of the ideal crystals is 0.985 mm and 793.719, respectively.