The solution of MgSO 4H 3BO 3H 2O system containing 20%(mass fraction)MgSO 4 and 2.5% H 3BO 3 was prepared and the experimental study of its crystallization at 180℃ were carried out in a high pressured vessel. Only a solid phase MgSO 4·H 2O was separated out from the system.The experimetal data were fitted.With the aid of simplex optimum method and RungeKutta digital solution of a set of differential equations, Singlenuclear interface reaction model (MB2) was selected to describe the process of crystallization of kieserite. the dynamic equation is as follows: -dc/dt=0.064(2.24-c) 4/3 (c-0.290)
