Shandong gold mine accident, just 100 meters serious congestion, why not use shield machine?

You can't use a shield machine. There is no landslide and gravel on the shaft wall, but water, ventilation pipes, cables, ladders and other facilities fall and are blocked. If there is gravel, it will be more troublesome. Shield machine was not originally used in this situation. No.3 and No.4 holes have been drilled, and the efficiency can be said to be very high. But these holes are efficient because they are so small that they can only transmit materials and information, not people. In the case of no explosion, the main shafts must be unobstructed, and these shafts need people to shuttle back and forth, and there is enough space. However, after the explosion, some areas collapsed and a large number of rocks blocked the passage. If it's just rocks, it's not too difficult to dig through. The key lies in some original fittings in the tunnel, such as metal scaffolding and metal pipes that fix the passage.

These metal pipes form a mixture with broken rocks and are difficult to clean. It is very difficult to clean even with a shield machine. The shield machine is designed for fixing rocks, and there is no way to deal with metals. The stone under the gold mine is too hard and the mine is too deep. Cheng Ming said that this is a common problem encountered by several rigs. Gold mine is different from sedimentary rocks in coal mine, because its drilling speed is fast and soft, while gold mine "gets harder as it goes down, and the drill bit likes to drill in soft places." Even though the rig delivered this time has the function of drilling hard rocks, its speed is slower than that of coal mines, gypsum mines and other mines. In order to deal with hard stones, almost every drilling rig has to be used in conjunction with an air compressor. The broken stone heads are crushed by the wind and screened to the size of sand particles, and then the sand particles return to the ground with the drilling fluid. A few days after the explosion, the air was bad, so we had no choice but to encourage each other. Master Du said that the miners chose to wait for rescue.

The education and training of miners' brothers is not in place, and the pre-job training of first aid and self-help emergency measures should be more detailed. The second explosion of gas, especially dust, is the normal state. After all, there is only one life, and the cause of this accident should not be caused by gas explosion, because coal will produce harmful gases such as methane and carbon monoxide in the process of occurrence, which is also commonly known as gas.

I really appreciate the efforts of frontline rescuers, who work overtime for the hope of miners' friends. However, whether the middle section where the miners were found and how many meters away from the shaft can better explain the success of this rescue, and draw more valuable experience for future rescue through this rescue. Some safety awareness needs to be popularized. It is right for miners in distress to save themselves, but they should know how to save themselves. How to avoid danger and save yourself is the safest. It is best not to take risks under the premise of unknown uncertainty, because they will never give up and they are not sure. It's best to wait for help in situ.