Research and application of slot raise under the fill with one-time grooved blasting technology.

Cut patio construction was a critical process in the medium-deep hole or deep hole mining methods, which mainly included staged blasting or one-time grooved blasting. Cut patio was essential in the medium-deep hole mining technology. The common method, the conventional raising, cage raising and climber raising method was usually used to construct the cutting patio, which has great safety risks and low excavation efficiency, which seriously affects the mine production. In recent years, Sanshandao Gold Mine has researched downward sublevel filling mining with medium and deep hole blasting. This research was currently facing the problem of cut patio construction under the backfill roof. This study demonstrated a one-time grooved blasting method fitting the backfill roof condition and its application. By comparing the characteristics of the straight-hole cutting method and the blasting crater method, the straight-hole cutting method was selected for the cut patio construction. By calculating blasting parameters, the diameter of the charging hole was Φ65 mm, and the diameter of the compensation hole was Φ110mm. The distance between the charging and empty holes was 0.3m, which could meet the requirements of blasting compensation space and free surface. In consideration of the surrounding rock stability conditions, a nine-hole cutout method was selected, containing 29 holes, where the cutout hole was designed with 1 central charging hole, 12 empty holes as compensation holes, 4 auxiliary holes, and 12 peripheral holes, after determining the blast hole plugging length, explosive selection, charge structure, differential time, detonation sequence and other process parameters, an in-situ industrial test of cut patio construction was carried out. The industrial test showed that the one-time grooved blasting plan for patio construction was feasible. The blasting rock particle size is uniform with no large blocks and excessive powder, the blasting disturbance is minor, and the blasting patio dimensions meet the design requirements. Overall, this test provided experiences and a reference basis for other one-time grooved blasting technical applications with similar conditions. [ABSTRACT FROM AUTHOR]