Abstract: Nanfen open-pit iron ore is a multi-stage mining mine， and the current implementation is the side slope extension from the third phase to the fourth phase. Because the minimum working surface of the fourth-phase expansion area is far away from the mining and stripping surface of the main mining field in the third-phase，lower stage in height， long transition time cannot guarantee the high-yield and stable transition of the ore. In the case that the original development transportation road leading to the main stope is blocked by the rolling stone caused by the expansion， most of the ore in the main stope must be transported in a long distance through the development transport system at lower plate. In view of the above situation， it is preferred to expand a narrow inclined strip on the upper plate to increase the amount of mining in the third stage. At the same time， a safe and reliable， economical and reasonable temporary transportation road is opened up on the upper plate to create conditions for keeping continuous stable production and lowering transportation cost.

Key words: Phased mining, Bench group, Tilting strip, Stable production transition, Development and transportation