Abstract: COREX static model and experimental system were developed to study the COREX-C3000 melter gasifier. The model was established on the basis of the material balance and heat balance, and its input parameters were set according to the operating parameters of production process. The results of static model were used for setting the parameters of physical experiment. COREX physical experimental system was based on the similar principles. The internal information of the physical model was obtained by thermocouples and observation panel. It was found that with the increase of discharge rates, wax/maize volume ratio, air temperature and air flow, the possibility of collapsing is increased. And the influence of collapsing in the raceway is preliminary analyzed.