Coal mine surrounding rock control method based on chemical modification

A technology of surrounding rock control and chemical modification, which is applied in ground mining, mining equipment, earthwork drilling and mining, etc., can solve the problems of poor effect and difficult construction, and achieve the effect of convenient use, simple method and safe mining

CN110685688AActive Publication Date: 2020-01-14CHINA UNIV OF MINING & TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-01-14

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Abstract

The invention discloses a coal mine surrounding rock control method based on chemical modification. Firstly, a rock mass required to be modified (hard rock stratum or fractured surrounding rock) is subjected to drilling construction, and then chemical reagents (softeners or hydrochloric acid and sodium carbonate are combined) are injected into a borehole, so that the hardness and integrity of therock mass is changed, namely that the rock mass is weakened or hardened; the situation that the hard rock stratum forms a large unsupported roof behind a working face is avoided; the first roof weighting pace and the periodic roof weighting pace is reduced, so that the accidents of air impact and roof impact caused by instantaneous caving of a hard roof behind the working face are avoided; the problems of accumulative energy release and stress transfer of a tunnel roof, and a coal seam hard roof required to be weakened near other tunnels are solved, and meanwhile the problems of loose and fractured surrounding rock mass strengthening are solved; and thus, the subsequent safe mining of a coal roadway is ensured effectively. In addition, the method is simple, low in cost, easy to use, and high in practicability.
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Description

technical field

[0001] The invention relates to a coal mine surrounding rock control method, in particular to a coal mine surrounding rock control method based on chemical modification. Background technique

[0002] During coal mining, when the integrity of the roof above the coal seam is good, the self-stabilization ability is strong, the strength is high, and the joints and fissures are not developed, the initial pressure step and the periodic pressure step will increase, resulting in the top of the goaf. Produces a large area of ​​overhang. The roof in this case will form air impact and roof impact when it falls in an instant, which will cause great potential safety hazards for underground personnel, mechanical equipment, etc. At present, 1 / 3 of the coal mines in my country belong to the hard roof coal seam. In order to ensure the safe and efficient production of coal, it is necessary to reduce the area of ​​roof leakage and prevent the large area of ​​the roof from bein...

Examples

Embodiment Construction

[0022] The present invention will be further described below.

[0023] As shown in the figure, the concrete steps of the present invention are:

[0024] A. After the excavation of the roadway 2 is completed, the hardness of the hard rock formation 4 above the roadway 2 is tested. If the Platts hardness coefficient of the hard rock formation 4 exceeds 8, then enter step B, otherwise enter step D;

[0025] B. Construct multiple rows of weakened boreholes 3 toward the hard rock formation 4 on the inner wall of the roadway, the row spacing between adjacent rows is 1-10m; the distance between adjacent weakened boreholes 3 in each row is 0.5m-5m;

[0026] C. Using the retreating grouting method, inject softener into each weakened drill hole 3 sequentially with a hydrostatic pressure greater than 2.5 and seal the holes. The hole sealing time is 1 hour, so that the softener can fully react with the hard rock formation 4, and then inject repeatedly softener and seal the hole until the...