Abstract: In order to fully recover the hanging wall ore resources,according to the occurrence conditions of hanging wall ore in a deep open pit mine in Panxi and the situation of internal dumping,this paper puts forward the technology of "continuous backfilling of internal dumping and step-by-step mining of hanging wall ore". The temporary road is built to the wide platform by using the inner dump to create the equipment operation space for the mining work. At the same time,the continuous backfilling of the mining pit shortens the exposure time of the slope after the mining of the hanging wall ore. The pre-splitting blasting is used to control the single sound initiation charge below 250 kg,and the equivalent load is loaded in the mining area. After calculation,the maximum vibration speed of the slope is 1. 6 cm/ s,which meets the safety speed requirements of the slope. The three-dimensional model of the slope is established,and the change of the slope displacement in the whole process of the mining process is calculated. After the completion of the mining,the overall displacement of the slope is less than 0. 5 cm, and there will be no large-scale slope instability. The field application shows that the cumulative output of ore is more than 583. 4 thousand tons,and the slope is stable. It provides technical support for the next step of comprehensive mining of hanging wall ore resources,which can be used for reference by similar mines.

Key words: deep open-pit mine,internal dumping,hanging wall ore,safety mining,slope stability