CN110630263B

CN110630263B - Layered mining method for huge thick coal seam with middle gangue layer

Info

Publication number: CN110630263B
Application number: CN201810991692.9A
Authority: CN
Inventors: 王旭锋; 郝鑫宇; 张东升; 秦冬冬; 文杰; 王选琳; 杨欢
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2018-08-29
Filing date: 2018-08-29
Publication date: 2021-04-27
Anticipated expiration: 2038-08-29
Also published as: CN110630263A

Abstract

The invention discloses a layered mining method for a huge thick coal seam with a middle gangue-containing layer, belonging to the technical field of efficient mining of the huge thick coal seam. The method comprises four steps of layering division, first layering mining, two layering mining and bottom layering mining. The layering division is based on high efficiency and high recovery rate, takes the reduction of mining disturbance influence as a principle, and determines the layering position and thickness according to the coal body crushing expansion coefficient and the coal caving height; fully mechanized caving mining is adopted in the first layer, and a metal net is laid at the bottom of a working face; fully mechanized caving mining is adopted in the two layers, and the goaf is filled to the maximum extent by utilizing the loosening, crushing and swelling characteristics of the gangue layers and the coal bodies with certain thicknesses above and below the gangue layers; when the bottom layer is mined, all the crushed coal bodies are discharged at one time. The method can reduce the disturbance of the layered mining of the huge thick coal seam to the overlying rock stratum, and crush the gangue in the middle and the nearby coal body through two mining, so that the gangue is easy to discharge, and the recovery rate can be effectively improved.

Description

Layered mining method for huge thick coal seam with middle gangue layer

Technical Field

The invention belongs to the technical field of high-efficiency mining of a huge thick coal seam, and is mainly applied to layered caving mining of the huge thick coal seam. In particular to a method for mining 45-55m thick coal seam layers with a gangue layer in the middle part.

Background

China is the first major coal producing country in the world, the reserves and the yields of the huge thick coal seams have a large proportion in national coal production, and the coal resources in northwest China have large reserves, shallow buried depths and large coal seam thicknesses, so that the coal seam mining method has a good mining prospect. The high-efficiency mining of the huge thick coal seam is vital to the improvement of the coal yield of China.

In recent years, for the exploitation of a huge thick coal seam, the commonly used methods in China mainly comprise layered fully mechanized mining, layered fully mechanized caving mining, large mining height fully mechanized caving and the like. Aiming at a 45-55m huge thick coal seam with a gangue layer in the middle, the common mining method has large influence on overlying strata disturbance, the mining rate is relatively low, and the production requirement of high efficiency and high recovery rate is difficult to meet. The main reasons for the problem are two aspects, on one hand, the middle gangue layer of the coal bed can seriously affect the discharge of top coal, the top coal caving performance is poor, and the recovery rate is reduced; on the other hand, due to the limitation of the existing mining process (the thickness of a coal seam mined at one time is limited), part of coal resources are retained in a goaf, and the loss of lost coal is serious. Therefore, a safe and efficient mining method suitable for 45-55m thick coal seams with gangue layers in the middle is needed to uniformly solve the problem of safe and efficient mining of the coal seams with the thickness.

Disclosure of Invention

In order to solve the problems, the invention provides a method for mining a huge thick coal seam with a middle gangue layer in a layering manner. A45-55 m thick coal seam with a gangue-containing layer in the middle is mined in 3 layers, and after layered mining, the gangue-containing layer is broken into small blocks under the influence of two mining operations, so that the small blocks are easy to discharge, and the mining rate can be effectively improved.

The invention aims to solve the problem of high-efficiency and high-recovery-rate mining of a 45-55m thick coal seam containing a gangue layer in the middle, and comprises the following steps:

a. the layered division is to determine the layered position and thickness according to the coal body breaking expansion coefficient and the coal discharge height, wherein the first layered position is at the upper part of the coal bed, the coal body with certain thickness is left above the gangue clamping layer, the second layered position is at the middle-lower part of the coal bed, the coal body with certain thickness is left below the gangue clamping layer, and the bottom layered position is at the bottom of the coal bed;

b. in the first layered mining process, a metal net is laid at the bottom of a working face to prevent gangue from mixing into a lower coal body;

c. in the two-layer mining, a fully mechanized caving face is arranged at the lower part of a gangue clamping layer, and a goaf is filled to the maximum extent by utilizing the crushed expansion characteristics of the gangue clamping layer and a coal body with a certain thickness above and below the gangue clamping layer;

d. bottom layer mining is to arrange a working face at the bottom of a coal seam, and in the process of extraction, the crushed and expanded coal at the top is discharged at one time.

Compared with the prior art, the invention has the beneficial effects that:

in the method, 3-layer mining is carried out on the huge thick coal seam with the middle part containing the gangue layer of 45-55m, wherein after the second layer is mined, the goaf is filled to the maximum extent by utilizing the crushing and swelling characteristics of the coal body above the second layer, so that the disturbance influence of mining on overlying strata can be effectively reduced; the middle part of the gangue is influenced by the secondary mining of the second layering and the bottom layering, the crushing degree is higher, the lumpiness is smaller, the top coal on the gangue can be discharged, and the mining rate can be effectively improved.

Drawings

The accompanying drawings are included to provide a further understanding of the process of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the process of the invention and together with the description serve to explain the invention and not to limit the process of the invention.

FIG. 1 is a schematic view of a fully-layered mining face of the method of the present invention.

FIG. 2 is a schematic diagram of the layering division of the method of the present invention.

FIG. 3 is a schematic view of the first zone mining of the method of the present invention.

FIG. 4 is a schematic illustration of a second stratified top-coal extraction process according to the present invention.

FIG. 5 is a schematic view of bottom zone mining in accordance with the method of the present invention.

Corresponding reference numerals in the figures are:

1-a middle gangue layer; 2-coal body at the lower part of gangue inclusion; 3-overburden; 4-coal body on the upper part of the gangue; 5-a metal bottom net; 6, crushing the gangue layer; 7, crushing the coal body at the upper part of the gangue layer; 8, crushing coal at the lower part of the gangue layer; 9-hydraulic support; 10-loose coal to be discharged.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the drawings and examples.

As shown in fig. 2 to 5, a 50m thick coal seam containing 2m gangue layers in the middle of a certain mine in Xinjiang is used as an engineering background, and the specific implementation mode is as follows:

a. dividing a coal bed into 3 layers (figure 2), wherein the first layer is positioned at the top of the coal bed and has the mining thickness of 20m, the second layer is positioned at the position 5.5-19m below a gangue layer and has the mining thickness of 13.5m, the bottom layer is positioned at the bottom of the coal bed and has the mechanical mining height of 5m, wherein a coal body with the thickness of 4m is reserved at the upper part of the gangue layer, and a coal body with the thickness of 5.5m is reserved at the lower part of the gangue layer;

b. the fully mechanized caving mining method is adopted in the first layer, the mechanical mining height is 5m, the coal caving height is 15m, the mining thickness is 20m (figure 3), a metal net is paved at the bottom of the working face along with the forward advance of the working face, the specification of the metal net is 100 multiplied by 100mm, and the gangue on the top plate is prevented from being mixed into the coal body on the lower part;

c. arranging a fully mechanized caving face at the lower part of the gangue layer for second sublevel mining, wherein the mechanical mining height is 5m, the coal caving height is 8.5m, the mining thickness is 13.5m (shown in figure 4), the second sublevel goaf is filled to the maximum extent by utilizing the crushing and swelling characteristics of the gangue and upper and lower coal bodies (11.5 m in total), the crushing and swelling coefficient of the coal body is 1.3, the maximum filling thickness can reach 15m, and the coal caving height during plantar sublevel mining can be filled; compared with the conventional layered mining method, the mining thickness is reduced by 15m, and the disturbance of coal seam mining to overlying strata is effectively reduced;

d. when the bottom layer mining is carried out, a working face is arranged at the bottom of the coal seam, the mechanical mining height is 5m (figure 5), and the crushed and expanded coal bodies of the second layer are all discharged at one time in the process of stoping.

Although particular embodiments of the present invention have been described herein, it will be understood that the above-described embodiments are exemplary and should not be construed as limiting the present invention, and that certain changes, modifications, substitutions, and alterations can be made therein by those of ordinary skill in the art without departing from the principles and spirit of the invention.

Claims

1. A method for mining a huge thick coal seam with a middle part containing gangue in a layering way is characterized by comprising the following steps: the method comprises four steps of layering division, first layering mining, two-layering mining and bottom layering mining;

layering and dividing: determining the layering position and thickness according to the coal body crushing expansion coefficient and the coal discharge height, wherein the first layering is positioned at the upper part of a coal seam, and a coal body with a certain thickness is reserved above a gangue clamping layer; the bisection layer is positioned at the middle lower part of the coal bed, and a coal body with a certain thickness is reserved below the gangue clamping layer; the bottom layer is positioned at the bottom of the coal bed;

in the first layered stoping process, a metal mesh is laid at the bottom of a working face to prevent gangue in a goaf from mixing into a lower coal body;

in the two-layer mining, a fully mechanized caving face is arranged at the lower part of a gangue clamping layer, and a goaf is filled to the maximum extent by utilizing the crushed expansion characteristics of the gangue clamping layer and a coal body with a certain thickness above and below the gangue clamping layer;

the bottom layer mining is to arrange a working face at the bottom of a coal seam, and the crushed and expanded coal at the top is discharged at one time in the process of extraction.