Based on the Matlab platform

identification model was established by the output error model in system identification method to determine the model of alumina high-pressure dissolving temperature model.The results reveal that step response curve of the second-order model is fitted basically with the online temperature trace which collected by alumina high-pressure digestion acquistion at worksite

and degree of fitting reaches 86.27%.The stability of the system is verified by the algebraic stability criterion.The identification model is reasonable and effective

which can provide the model basis for parameter setting and optimizing control.At the same time

the control precision of the system is improved

and the dissolution rate of alumina is increased with the decrease of the energy consumption.