基于逆溶解度性质的硫酸钠-水体系成核动力学的研究

以逆溶解度性质的硫酸钠-水体系为研究对象,通过聚焦光速反射测量技术对硫酸钠-水体系升温结晶成核行为进行了研究,考察了升温速率、饱和温度对介稳区宽度的影响,通过经典成核理论模型确定了成核动力学参数,探讨了化学势和成核温度对成核速率的影响。结果表明：较小的升温速率、较高的饱和温度都会使介稳区宽度变窄;溶质在固液两相中的化学势差是结晶过程的驱动力,但它并不总是有利于成核过程。以上研究不仅为硫酸钠升温结晶工艺过程开发提供了基础物性数据,还有助于深入理解此类逆溶解度类型升温结晶的成核行为。

Study on nucleation kinetics of sodium sulfate-water system based on inverse solubility

Based on the inverse solubility of sodium sulfate-water system,the nucleation behavior of sodium sulfate-water system was studied by focused light velocity reflection measurement.The effect of heating rate and saturation temperature on the width of metastable zone was investigated.The nucleation kinetic parameters were determined by classical nucleation theory model,and the effect of chemical potential and nucleation temperature on the nucleation rate was discussed.The results showed that smaller heating rate and higher saturation temperature will narrow the width of metastable zone.The chemical potential difference of solute in solid-liquid two-phase was the driving force of crystallization process,but it was not always conducive to nucleation process.The above research not only provides basic physical property data for the development of sodium sulfate heating crystallization process,but also helps to deeply understand the nucleation behavior of this system with inverse solubility in the heating crystallization process.