高氯酸铵的球形化结晶工艺和性能表征

为获得球形化高氯酸铵(AP),利用重力法测试了AP在水中的溶解度,采用Vant′t Hoff方程和Apelblat方程对溶解度数据进行拟合,建立溶解度模型;采用冷却结晶法制备了球形化AP晶体,分析了结晶液初始质量分数、搅拌速率、降温速率及养晶时间对产品形貌及粒度分布的影响;分别对非球形AP原料和球形化AP样品进行了吸湿性能、松散堆积密度、流散性、热稳定性的表征。结果表明,AP在水中的溶解度随着温度的升高而增加,Apelblat方程和Vant′t Hoff方程的R²接近于1,且MAPD均小于3%;最佳冷却结晶工艺为:搅拌速率为230r/min,结晶液初始质量分数为35%,降温速率为0.5℃/min,养晶时间为3h;球形化AP样品的吸湿性能、松散堆积密度、流散性、热稳定性相比于非球形AP原料有明显改善。

Crystallization and Characterization of Spherical Ammonium Perchlorate

In order to obtain spherical ammonium perchlorate(AP),the solubility of AP in water was determined by the gravity method.The Apelblat equation and Vant′t Hoff equation were used to fit the experimental solubility data to establish the solubility model.The spherical AP crystals were prepared by cooling crystallization.The effects of initial concentration of AP solution,stirring rate,cooling rate,and crystal growth time on the morphology and particle size distribution of the product were analyzed.Meanwhile,moisture absorption performance,loose bulk density,flow dispersion,and thermal stability of the raw AP and the spherical AP were characterized.The results show that the solubility of AP in water increases with the increase of temperature.For both Apelblat equation and Vant′t Hoff equation,the R² values and the MAPD values are close to 1 and less than 3%,respectively.The optimized cooling crystallization conditions are:the stirring rate of 230r/min,initial concentration of 35%,cooling rate of 0.5℃/min,and crystal growth time of 3h.In addition,the hygroscopicity,loose bulk density,dispersibility and thermal stability of spherical AP have improved significantly compared to that of non-spherical AP.