摘要
研究了25、40、55℃条件下软钾镁矾和氯化钾转化结晶硫酸钾的过程,针对不同时刻液相和固相进行化学分析及鉴定;结果表明,氯化钾溶解速率大于软钾镁矾的溶解速率;硫酸钾结晶发生迅速。软钾镁矾的溶解速率随温度升高而增大,氯化钾溶解速率随着温度升高变化不明显;硫酸钾结晶速率也随着温度升高而增大,但收率随着温度的增加而减少;采用非线性拟合计算出系列温度条件下,硫酸钾结晶的量以及软钾镁矾和氯化钾溶解量与时间的关系。结合动力学模型模拟计算,得到溶解和结晶动力学方程,得出反应速率常数和反应级数,运用Arrhenius公式计算溶解和结晶的活化能;提出了溶解及结晶转化机理。
Transforming crystallization of K2SO4 from picromerite（Pic）and KCl reaction under temperatures of 25,40 and 55℃was studied.Liquid and solid phases at different stages were chemically characterized.The results show that KCl dissolves faster than Pic under these temperatures with rapid K2SO4 crystallization.The dissolution rate of Pic increases with the increase of temperature,while the dissolution rate of KCl is not affected.Moreover,the crystallization rate of K2SO4 increases but its yield decreases with the increase of temperature.The profiles of K2SO4 yield and Pic/KCl dissolution amounts as a function of time are nonlinearly fitted under these temperatures,respectively.Equations of dissolution and crystallization kinetics are obtained with dynamic model simulation,and reaction rate constants and reaction orders are calculated.Arrhenius formula is used to calculate activation energies of dissolution and crystallization,and dissolution and crystallization mechanism are proposed.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2017年第3期521-529,共9页
Journal of Chemical Engineering of Chinese Universities
基金
高新技术研究与发展计划(2012-G-212A)
青海省科技支撑项目(2013-G-139A)
关键词
软钾镁矾
硫酸钾
动力学
相图
picromerite
K2SO4
kinetics
phase diagram
