## 4 The Process of Changing Mining Methods in Mines
### Mining Method Implementation  
1. Segment setup  
According to the rock drilling equipment used in the mine and taking into account that the greater the height of the section and the smaller the number of sections, the amount of mining work will be reduced accordingly, but the efficiency of rock drilling will be reduced accordingly and the difficulty of loading and blasting will be increased accordingly. According to the existing engineering arrangement, it is decided to set up an additional \(-500\) m section level.  
2. Mining site layout  
The ore chamber and pillars are arranged vertically on the strike of the ore body in an alternating pattern with a width of 18 m, a length of 72 m, and a height of 85 m. Pillars of sufficient width of the pan zone are left in the stope to recover as much of the resource as possible.  
3. Preparatory mining and cutting  
The layout of the mining alignment works is shown in Figure 10, including the sectional contact road, riffle pulling the bottom roadway out of the mine roadway, rock drilling chamber, sliding shaft, cutting works, etc.  
4. Mining process  
Rock drilling and blasting was performed using a domestic QZCT90Y high-pressure cart to drill upward fan-shaped medium-deep holes with a chipping step of 4.0 m and 1 ms\(\sim\)9 ms segmented microdifferential blasting to form a V-shape rift groove. The designed hole diameter was 80 mm. The row spacing of blast holes was 2.0 m. The stemming length of fan-shaped medium-length hole trench blasting was 1.3 m to 11.3 m. The calculated ore fragmentation per meter of blast hole was 8.46 tons/m, and the unit explosive consumption was 0.33 kg/t, as shown in Figure 11a. In the rock drilling chamber, the SIMBAH364 rock drilling cart was used to drill downward vertical deep holes with a plugging length of 2.0 m-3.0 m, and the designed hole diameter was 120 mm. The row spacing of blast holes was 3.0 m. The unit explosive consumption was 0.29 kg/t to 0.31 kg/t, with an average of 0.30 kg/t. The specific arrangement is shown in Figure 11b.  
Figure 10: Mining method diagram of sublevel open stope subsequent filling method.  
5. Ore release  
After each blasting and exhausting the smoke through adequate ventilation, the LH514E 6 m\({}^{3}\) electric loader is used to load and unload the chipped ore into the ore pass from the mine roadway and mine approach, which falls into the V-shaped riffle at the bottom of the stope, and the actual production capacity of the loader can reach up to 600 t/shift according to the calculations. After each blast, 1/3 of the ore is discharged, and the other 2/3 of the chipped ore is left in the stope so that the subsequent blasting can be performed by extrusion blasting to reduce the rate of chunking and the vibration of the blasting, and the retained ore can play a role in maintaining the stability of the surrounding stope or the filling body and reduce the loss of ore and the rate of dilution. After the entire stope mining is completed, the ore in the stope will be shoveled out centrally.  
6. Filling process  
After the centralized discharge of ore from the stope is completed, filling should be carried out in time to avoid the collapse of the surrounding stope or filling body due to the long exposure time of the goat. The pressure of the filling slurry on the retaining wall is large, so for safety reasons, a concrete masonry retaining wall is used, and water drainage pipes are laid at the bottom, middle, and top of the retaining wall.