AU2012354005B2

AU2012354005B2 - Method of prevention and control zonal coal and gas outburst

Info

Publication number: AU2012354005B2
Application number: AU2012354005A
Authority: AU
Inventors: Baiquan LIN; Wei Yang; Cheng ZHAI
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2011-12-30
Filing date: 2012-03-29
Publication date: 2015-08-27
Anticipated expiration: 2032-03-29
Also published as: RU2013125335A; CN102444402A; WO2013097370A1; RU2554605C2; AU2012354005A1; CN102444402B; RU2554605C9

Abstract

Abstract The present invention provides a method of prevention and control zonal coal and gas outburst, which is characterized in that the mining area is divided into mining zones appropriately in a way that the maximum ground stress direction along horizontal direction in every mining zone is 5 essentially the same, and the coal heading and driving direction are arranged in parallel to the maximum ground stress direction along horizontal direction as far as possible by adjusting the mining direction at the working face, so as to reduce ground stress concentration at the end of the working face and reduce coal and gas outburst hazard in the coal driving and mining process at the working face, and thereby reduce the hazard of coal and gas outburst in the mine in overall.

Description

Description ) Method of Prevention and Control Zonal Coal and Gas Outburst Field of the Invention [1] The present invention relates to a method of prevention and control zonal coal and gas 5 outburst, which is especially suitable for zonal prevention and control of coal and gas outburst for coal seams with coal and gas outburst hazard. Background of the Invention China has a high demand for energy. Coal accounts for more than 70% in the energy [2] structure. Large quantities of coal seams with coal and gas outburst hazard have to be 10 exploited to meet the demand of national production. Coal and gas outburst may result in tremendous casualties and property losses. To prevent coal and gas outburst accidents, two methods of prevention zonal coal and gas outburst are mainly used at present, i.e., mined seam protection method and zonal pre-drainage method. Though the mined seam protection method has great protection and prevention effect, it is only applicable to a coal seam group condition; in addition, if the spacing between the protecting seam and 15 the protected seam is beyond the range of protection, the pressure relief effect of the protected seam is not enough so the outburst prevention effect is not satisfactory; owing to the fact that the air permeability of most coal seams in China is poor, the zonal pre drainage method does not provide satisfactory prevention effect, and cannot eliminate coal and gas outburst hazard timely and effectively. It is urgent task to achieve zonal 20 outburst prevention and control for coal seams with coal and gas outburst hazard in cases the mined seam protection method and zonal pre-drainage method cannot effectively eliminate coal and gas outburst hazard. Disclosure of the Invention Technical Problem 25 [3] Embodiments of the present invention preferably provides a method of prevention and control zonal coal and gas outburst, which is simple but it can attain favorable outburst elimination effect and reduce stress concentration at the working face. Technical Solution [4] The present invention provides a method of prevention and control zonal coal and gas 30 outburst, comprising: [5] a. dividing the mining area into mining zones by the distribution of faults and folds in the mine in a way that the boundaries of the mining zones are in the axial parts of faults or folds as far as possible; [6] b. determining the maximum ground stress direction along horizontal direction in the 35 mining zone, by a conventional method of testing ground stress;; 7] when the included angle between the measured maximum ground stress direction along 2 horizontal direction and the coal seam course is smaller than 450, arranging intake airway and return airway for the mining zone along the inclination of the coal seam and then driving, and arranging intake airway and return airway for working face along the coal seam course and then driving, so as to carry out mining at a working face arranged along the coal 5 seam course,; [8] when the included angle between the measured maximum ground stress direction along horizontal direction and the coal seam course is greater than 450, arranging intake airway and return airway for the mining zone along the coal seam course and then driving, and arranging intake airway and return airway for working face along the inclination of the coal 10 seam and then driving, so as to carry out mining at a working face arranged along the inclination of the coal seam. Beneficial Effects [9] Researches indicate that the ground stress field is a stabilized unstable field, which has high difference on a large scale but is relatively stable on a small scale. In the present invention, 15 the mining area is divided into mining zones appropriately in a way that the boundaries of mining zones are in the axial part of faults or folds, so that every mining zone is in the same geologic unit, and the ground stress field is relatively stable and the horizontal maximum ground stress field is essentially in the same direction in the scope of the same mining zone. Since the mining work is carried out at the working face mainly along the coal seam course 20 or inclination of coal seam, the coal heading can be arranged in parallel to the maximum ground stress direction along horizontal direction by optimizing the coal seam mining direction; therefore, ground stress concentration at the end of the coal heading can be reduced, and the coal and gas outburst hazard in the driving process can be alleviated in overall. On the basis of optimization design of the entire mine and mining zone system, the 25 method disclosed in the present invention can reduce the hazard of coal and gas outburst in mines in overall, and has wide applicability and can attain a remarkable result. Brief Description of the Drawings [10] Figure 1 is a layout diagram of working face in a mining zone, in the case that the included angle between the maximum ground stress direction along horizontal direction and the coal 30 seam course is smaller than 450; [11] Figure 2 is a layout diagram of working face in a mining zone, in the case that the included angle between the maximum ground stress direction along horizontal direction and the coal seam course is greater than 450; [12] In the figures: 1 - intake airway for working face, 2 - return airway for working face; 3 35 return airway for mining zone; 4 - intake airway for mining zone; 5 - mining zone; 6 working face. Detailed Description of the Embodiments [13] Hereafter the present invention will be detailed in embodiments with reference to the accompanying drawings: 3 [14] In the method of prevention and control zonal coal and gas outburst according to the present invention, first, the mining area are divided into mining zones 5 by the distribution of faults and folds in the mine on the basis of the coal seam occurrence condition in the mine in a way that the boundaries of the mining zones 5 are in the axial parts of faults or folds as far 5 as possible; where a plurality of faults or folds exist, the axial part of the largest fault or fold among the faults or folds is selected as the boundary of mining zone, so as to avoid any faults or folds that may severely alter the ground stress field in the mining zone; in that way, every mining zone is controlled to be in the same geologic unit, to ensure that the horizontal maximum ground stress is in the same direction in a mining zone. The direction of 10 maximum ground stress along horizontal direction within the scope of a mining zone 5 is determined with a conventional method of testing ground stress, such as ground stress relief, hydraulic pressure fracture, or sound emission, etc.; since the mining direction at a working face in the mining zone 5 is mainly along the coal seam course or inclination, the major airways for the coal seam, such as intake airway 1 for working face and return airway 2 for 15 working face, are arranged along the mining direction at the working face 6. Different axial included angles between the maximum ground stress direction along horizontal direction and the coal heading will result in different ground stress concentration conditions at the end of the coal heading, and therefore result in different situations of coal and gas outburst hazard. 20 [15] To reduce the hazard of coal and gas outburst, when the included angle between the measured maximum ground stress direction along horizontal direction and the coal seam course is smaller than 450, intake airway 4 and return airway 3 for the mining zone are arranged along the inclination of the coal seam, and driving work is carried out; then, intake airway 1 and return airway 2 for the working face are arranged along the coal seam course, 25 and driving work is carried out, so that the mining work will be carried out at the working face 6 along the coal seam course; when the included angle between the maximum ground stress direction along horizontal direction and the coal seam course is greater than 45', intake airway 4 and return airway 3 for the mining zone are arranged along the coal seam course, and driving work is carried out; then, intake airway 1 and return airway 2 for the 30 working face are arranged along the inclination of the coal seam, and then driving work is carried out, so that the mining work will be carried out at the working face 6 along the inclination of the coal seam. [16] Since the intake airway 4 and return airway 3 for the mining zone are usually stone headings, there is no coal and gas outburst hazard; since the intake airway 1 and return 35 airway 2 for the working face are usually coal headings, the object of alleviating coal and gas outburst hazard in the driving work of coal mining and mining work at the working face can be attained by arranging these coal headings in parallel to the maximum ground stress direction along horizontal direction. The term "comprise" and variants of that term such as "comprises" or "comprising" are used herein to denote the inclusion of a stated integer or integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.

3A Reference to prior art disclosures in this specification is not an admission that the disclosures constitute common general knowledge in Australia or any other country.