K^+、NH_4^+//Cl^-、NO_3^-–H_2O体系硝酸钾冷却结晶动力学研究

Cooling Crystallization Kinetics of Potassium Nitrate in K^+,NH_4^+//Cl^-,NO_3^--H_2O System

采用间歇动态法研究了K^+、NH_4^+//Cl^-、NO_3^--H_2O体系中硝酸钾冷却结晶动力学,通过矩量变换法处理实验数据,回归拟合求得动力学参数,建立了该体系硝酸钾成核速率和生长速率动力学方程,分别为B^0=1.13×10^(12)·exp(-6.34×10~4/RT)△C^(4.68)M_T^(0.41)N_P^(0.50)、G=4.89×10~6 exp(-1.14×10~5/RT)△C^(3.79),简要分析了硝酸钾冷却结晶过程的影响因素。实验结果可以为氯化钾-硝酸铵复分解法生产硝酸钾结晶器设计提供基础数据,对结晶操作的优化具有指导意义.

The cooling crystallization process of potassium nitrate in K＋,NH_4＋//Cl-,NO_3--H_2O system was studied via intermittent dynamic method.The moment transform method was applied to the experiment data,from which the kinetic parameters were obtained with the least square method.The corresponding equations of the nucleation rate and the crystal growth rate thus obtained during the crystallization process of potassium nitrate in this system are B0=1.13×10（12）·exp（-6.34×104/RT）△C（4.68）M_T（0.41）N_P（0.50） and G=4.89×106 exp（-1.14×105/RT）△C（3.79）.Finally,the effects of the operation parameters were analyzed against these model equations.For the process of potassium nitrate produced through double decomposition reaction from potassium chloride and ammonium nitrate,the experimental results can provide basic data for crystallizer design,and have some guiding significance for the optimization of crystallization operation.