Abstract: A 3D semi-cylindrical physical model of COREX shaft furnace was established, and the initial position and evolution process of dust accumulation in the bustle pipe of a shaft furnace were investigated through this model. The effects of discharging rate, gas flow rate, and non-normal operation condition on dust accumulation in the bustle pipe were also studied. The results show that the initial position of dust accumulation in the bustle pipe is in the 8^#-12^# slot region, located before the supporting tube of AGD beam. The dust blockage is first formed in the packed bed near the slot and then blocks the slot and grows into the bustle pipe if the growth velocity of the blockage region is greater than the descending velocity. Finally, dust accumulation can be observed in the bustle pipe. The dust accumulation is still growing in the bustle pipe, and the edge of the dust pile could develop to the far side; thus, the other slots would be gradually clogged by dust. Moreover, the results confirm that with increased discharge and gas flow rates, dust accumulation in the bustle pipe is greatly hindered. In contrast, under non-normal operation conditions, the dynamic balance of dust blockage is broken, and dust accumulation in bustle pipe is easily formed.