Abstract: According to the situation of return fine rate in the upward medium-length hole charging process of Meishan Iron Mine,the measurement targets and key indicators are determined by analyzing the work processes.The explosives viscous（dispersion index) is analyzed by using DFMEA,the reasons are as follows:long transit time,great temperature difference between surface and underground and matrix volatile,the measures of the direct distribution by multi-purpose vehicle and matrix compensation of diesel can be taken to overcome the above difficulties effectively.The backward tube speed（continuous index) is conduct multiple regression analysis,the multiple regression fitting equation is obtained,based on the fitting equation,the optimal velocity value can also be obtained.the return fine rate values after improvement is collected,the process capability index values before and after improvement are conducted comparison and analysis,so as to verify the improvement effects.Finally,the improvement measurements and parameters are conducted solidification process to achieve the effective controlling of return fine rate of upward medium-length hole.The above study results in this paper related to some measures and parameters can provide some reference for the similar mines in our country.

Key words: Upward medium-length hole, return fine rate, Process capability, Regression analysis