Blocking of drawpoint or orepass is often happened during drawing process.

Reason analysis and treatment of ore pass choking-up;

Applying the air impact molding to the molding using complicated pattern with wider top surface, deep concave and bigger cod, there always exists a funnel blockade phenomenon and a lower sand mold compactibility at the entrance to the concave area.

Based on example of main gravity shaft stoppage disposal in Sijiaying Iron Ore Mine,the main reasons for stoppage and the usual disposal methods & experiences are explained.

Considering the affects of hopper blocking and belt wear breaking on production, an autostopper to prevent the belt hopper blocking has been developed and applied in the sintering plant of HANGANG, as a result, the similar accident was prevented effectively and the normal running of equipment was ensured.