Abstract: Based on the investigation of the wall rock caving law in mined-out areas and on the tests, a full set of technical system for mining the orebody with multi-mined-out areas was formed, including “technique of under-monitoring forced mining of orebody with multi-mined-out areas”, “ technique for recovering caved residual ore at the edge of active mined-out area”, “technique of drifting passing through loose body layer” and “new type sublevel caving with an inclined platform for drilling, blasting & ore-passing.” They have been used to effectively recover the orebodies destroyed by mined-out areas and residual orebodies in Tuancheng Iron Mine, resulting in prolonged production life of the mine and good economic and social benefits.

Key words: Orebody with multi-mined-out areas, Under-monitoring forced mining, Recovery of residual ore, Sublevel caving with an inclined platform