Abstract: Yuanjiacun Open-pit iron mine has a lot of mined-out areas by disordered underground mining after many years. According to the characteristics of underground mined-out area of Yuanjiacun Open-pit iron mine, the 1740-10-7# mined-out area is processed by the blasting caving method at a time by hole-by-hole blasting based on the Orica high precision millisecond non-electric detonator. The research results show that, the method of this paper can eliminate the potential safety hazard and ensure the production progress of open-pit iron mine at the same time.

Key words: Open-pit mining, Treatment of mined-out area, Deep hole blasting caving method, Blasting network