Abstract: Chengchao Iron Mine adopts non-pillar sublevel caving method and BQ-100 type charg⁃ ing device. The labor intensity of workers is high, the level of mechanization is low, and the blasting quality is unstable. In order to improve the level of mechanized operation, reduce the labor intensity of workers and improve the blasting quality, Chengchao Iron Mine introduced Charmec MC 605 DA charging trolley. Through the underground medium and deep hole charging blasting test, it is determined that the reasonable allocation of workers for the charging trolley is 4, and the applicable explosive is rock expanded ammonium nitrate explosive. The optimum technological parameters are as follows: the water content of explosive is controlled at about 5%, the pressure in tank is 0.50~0.55 MPa, the boost air pressure is 0.40~0.42 MPa, the pipe withdrawal speed is 0.30~0.34 m/s, and the powder return rate is controlled at about 10%. By compar⁃ ing and analyzing the advantages and disadvantages of the two kinds of charging equipment, the mecha⁃ nized operation level and safety of the charging trolley are higher than those of the BQ-100 type charging device, which reduces the labor intensity of workers and increases the excellent rate of blasting quality by 3%. The charging trolley has a certain reference significance for similar mines in China to realize the mech⁃ anization and automation of upward medium and deep hole charging.

Key words: non-pillar sublevel caving method, charging device, charging trolley, medium- length hole blast