Abstract: In light of the demand of the production transition from open pit to underground mining at Yanqianshan Iron Mine, AnSteel Group's Anshan Mining Co, and its orebody occurrence conditions and ore-rock characteristics, the authors points out two main issues that should be paid attention to in the production during the transition period, namely, the overlying layer thickness and the recovery of wall hanging resource, and analyze and discuss three possible underground mining methods, which can be of some guidance significance to the production during the transition.

Key words: Transition from open pit to underground mining, Overlying layer thickness, Wall hanging resource