Abstract: Aiming at the problem of arching and blockage caused by fine particle size，high water con⁃ tent and high sulfur content in the large flat-bottomed powder ore bin of Luohe Iron Ore Dressing Plant of Masteel in Anhui Province，a solution of pneumatic assisted flow clearing system is proposed. By analyzing the mechanical properties of the material and the structure of the warehouse，it is found that the increase of the internal friction angle of the material and the chemical reaction of the sulfide are the main reasons for the blockage. The designed pneumatic flow supporting system adopts the instantaneous injection technology of compressed air. Through layered arrangement of nozzles and automatic control，the friction resistance be⁃ tween materials is effectively reduced and the sintering block is destroyed. The practical application shows that the system significantly improves the fluidity of the silo，increases the effective volume utilization rate from 40% to 80%，avoids the safety hazards of manual clearance，and achieves the production goal of high efficiency，safety and environmental protection.

Key words: wall sticking, arching, large flat-bottomed powder ore bin, effective volume, pneumatic flow aid