The characteristics of the room and column method and its operation

The room and pillar method is a common mining method for returning the stable level of the mining rock and the ore body below the moderately inclined medium thickness. It is characterized by dividing the mining room and the pillars in the mining unit and alternating them. When returning to the mining room, the ruled pillars are left. (If only the stone or low-grade ore bodies are left as pillars, the pillars are arranged irregularly. It is called the comprehensive method, and its main mining process is basically the same as the room and column method) to maintain the roof of the goaf. The retained pillars may be continuous or discontinuous, and the discontinuous pillars are generally not harvested. Figure 1 is a conceptual diagram of the shallow-eye room method.

1—stage transportation and alley; 2—ore ore; 3—cutting alley; 4—electric winch winch;

5—cutting the patio (uphill); 6—the pillar; 7—the blasthole

1 ) Stope layout

In China, most of the mines using the room-column method use electric rafts to transport ore. Therefore, the long-axis direction of the mine is arranged along the ore body. The length is mainly determined according to the effective transport distance of the electric raft, which is generally 4m~60m. Stope width depending on the thickness and robustness of roof rock ore, are generally of 8 ~ 20m. The pillars are mostly round and have a diameter of 3 to 7 m. When the thickness of the ore body is large, a continuous (stripe) column should be left with a width of about 5 m.

2 ) Precision cutting

In the bottom rock of the ore body, the tunnel is transported in the extra-pulse stage (the mine production capacity is small, and the stage road can also be arranged in the ore body, called the pulse inner lane), at the center line of each mine, from Stage transport roadway tunneling ore chute 2. In the pillar below the mine, the electric winch winch chamber 4 is dug. In the upper part of the chute, along the ore body, the cutting and cutting alley 3 is driven, and the cutting flat road is expanded to the sides of the ore body to form a bottoming space. Along the center line of the mine, in the ore body, from the ore shaft to the bottom of the ore body, the cutting patio (uphill) 5 is used as a passage for pedestrians, ventilation, transportation equipment and materials, and a blasting free surface during mining.

3 ) Recovery

When the thickness of the ore body is less than 2.5~3.0m, it can be pushed forward according to the full thickness of the ore body; when the thickness of the ore body is greater than 3.0~3.5m, the bottom of the ore body is first pulled to form a bottom of 2.5m height. space.

Back to shallow-eye collapse, leaving the pillars at the design position while pulling and mining. After each blasting, after sufficient ventilation time (not less than 45 minutes) to eliminate the gun smoke, then the personnel enter the stope, first check the roof, handle the turquoise, and after confirming the safety, install the winch pulley, the electricity installed in the winch chamber The 耙 winch traction bucket will dump the ore under the collapse to the mine, and mine the mine car parked in the stage transport lane through the vibration miner. The motor vehicle will pull the mine train to the main mine mine to unload and lift The equipment is lifted to the surface.

4 ) Ventilation

The ventilation line of the mine is: fresh air flow from the stage transporting the alley, passing through the ore shaft of the unmining room into the cutting and alley to the mine room. After cleaning the working surface, the dirty wind is cut up the mountain and enters the transport lane of the upper stage ( At this stage, the return airway is discharged to the ground through the return air shaft.

5 ) Pillar mining

The pillars of the Fangzhu method generally account for 20~30% of the reserves. Under the condition that the mine is open, recycling is generally not carried out. If the ore is of high value, it can also be partially recovered according to the specific conditions: for continuous pillars, local recovery is divided into discontinuous pillars; for intermittent pillars, large sections can be contracted into small sections.

When the pillars are harvested, the workers work directly under the condition that the exposed area of ​​the roof rock is increasing. The safety is poor. Safety management should be strengthened. According to the different degrees of stability of the roof rock, temporary brackets are placed around the pillars.

6 ) Evaluation

The advantages of the room-column method (comprehensive method) are: small amount of precision cutting work, simple work organization and good ventilation; its main disadvantages are: the proportion of mineral ore is large, and generally does not carry out mining, therefore, the ore loss is more Big.

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