Mining method of high stress soft outburst coal seam

Abstract

The invention discloses a high-stress soft outburst coal seam mining method which comprises a coal seam gas extraction method, wherein the coal seam gas extraction method comprises the steps of drilling with an arc-shaped three-edge drill rod matched with the air compressing and slagging drill technique, extracting gas at the position close to a drilled hole, and conducting dedusting on the hole, average drilling depth is 75 m - 80 m, the gas releasing rate of a great coal working surface reaches over 60%, the content of residue gas of a protected coal seam is below 7 m<3> / t, and during tunneling of the great coal working surface, the absolute gas discharge is 2.0 m<3> / min - 2.5 m<3> / min, and the maximum gas density of a return current is about 0.3 percent; during stoping of a stope working surface, the absolute gas discharge is 3.5 m<3> / min - 4.5 m<3> / min, the maximum gas density of a return current is about 0.4 percent, and the gas density on a corner of the stope working surface is 0.6 percent at most; a hole deduster is used for dedusting during drilling, and then dust concentration of the working surfaces is reduced.

Description

technical field [0001] The invention relates to a coal mining method, in particular to a high-stress soft outburst coal seam mining method. Background technique [0002] At present, in coal mining, auger drill pipes or ribbed drill pipes are generally used to drill holes for gas drainage. However, for high-stress soft outburst coal seams, auger drill pipes have the following disadvantages: [0003] (1) Injection holes are prone to occur during the drilling process. After the injection holes occur, the load in the hole increases, and the phenomenon of drilling and sticking occurs. However, due to the wide blade of the auger drill pipe, the large amount of coal carried is easy to cause The phenomenon of drill pipe locking leads to the phenomenon of drill loss, which increases the cost of drilling construction; [0004] (2) The drill pipe is not lubricated by water, and dry friction with the coal body for a long time will easily generate high temperature or even sparks, which ...

AI Technical Summary

Problems solved by technology

[0003] (1) Injection holes are prone to occur during the drilling process. After the injection holes occur, the load in the hole increases, and the phenomenon of drilling and sticking occurs. However, due to the wide blade of the auger drill pipe, the large amount of coal carried is easy to cause The phenomenon of drill pipe locking leads to the phenomenon of drill loss, which increases the cost of drilling construction;

[0004] (2) The drill pipe is not lubricated by water, and dry friction with the coal body for a long time will easily generate high temperature or even sparks, which will increase the friction force, the drill pipe is easy to age, and the drilling speed is slow due to the influence of coal body conditions;

[0005] (3) Due to the dry drilling, coal dust is flying at the construction site, and the coal dust is likely to cause harm to personnel on the downwind side, and the coal powder is easily brought into the pipeline by the negative pressure of the drainage pipeline, posing a threat to the pipeline;

[0006] (4) Due to the large amount of slag discharged during the construction of the auger drill pipe, it is also more destructive to the coal body, which is likely to cause a sudden increase in the coal output of the drill hole, and the untimely discharge of the drill hole, resulting in the phenomenon of drill loss and increased The cost of drilling construction is reduced;

[0007] (5) During the drilling process of the auger drill pipe, it is necessary to always pay attention to the drilling pressure not to be too high. If the feeding pressure is too high when drilling into the soft coal seam, the auger bit will be pressed into the coal seam before cutting, resulting in dust per unit time. The amount increases, and it is easy to cause the phenomenon of diamond holding, which leads to the occurrence of diamond drop;

[0008] (6) In addition, because the auger drill pipe is connected by plug-in, if the drilling machine is not stable before drilling, the drilling machine will vibrate during the drilling process, causing the drill pipe to swing or flicker during the drilling process, causing the drilling to be off-center , the hole wall is not straight, which increases the resistance during drilling, weakens the forward ability, and weakens the forward ability. conditions of formation

[0010] (1) Due to the dry drilling and the use of wind slag removal, the coal dust on the construction site is not easy to control, which will cause harm to the drilling workers and the workers on the downwind side, and the coal powder is easily brought in by the negative pressure of the drainage pipeline. pipelines, posing a threat to pipelines;

[0011] (2) Due to the long-term hard friction between the outer blade of the rib drill pipe and the borehole wall, the drill pipe ages faster and the wear resistance needs to be increased;

[0012] (3) Since the rib drill pipe is screwed with a tapered thread, the drill pipe cannot be reversed during the drilling process, and the ability to deal with buried drill and stuck drill is not strong, and it is necessary to pay attention to the drilling speed and drilling speed at all times. pressure