Abstract: The orebody of Zhangjiaxialou Iron Mine is overlaid with large thickness Quaternary,the orebody belongs to difficult-mined orebody,and it is characterized by slowly inclined and inclined medium-thickness and large-thickness.In order to realize the goal of safety and high efficient mining of the orebody,the thickness of top pillar is calculated by using the method of ratio of thickness and span,beam theory of structural mechanics,empirical formula method and numerical simulation method,the optimal value is 24 m.Based on the above study results,in view of the orebody characteristics,the sublevel open stoping backfilling method based on open stoping approach ore removal and footwall vein ore removal is designed.Through economical and technical comparison,the open stoping approach ore removal scheme based on remote scraper is help for reducing engineering quantity of mining and cutting,and the mining cost per ton can be reduced more than 20％,its performance is better than the other ore removal method,therefore,the sublevel open stoping backfilling method based on open stoping approach ore removel can be regarded as the optimal mining method of the mine.

Key words: Slowly inclined medium-thickness and large-thickness orebody, Thickness of ore pillar, Open stoping approach ore removal, Remote scraper, Sublevel open stoping backfilling method