Keywords: coal mining; Technology; Methods; Security; sustainable development
China Library Classification Number: TD 163 Document Identification Number: A.
Coal mining technology and reform must face the main battlefield of economic construction under the influence of the new situation of scientific and technological economic development and the development needs of local coal mines, so as to stand on the forefront of coal mining technology and play a certain role in solving practical problems in coal industry engineering. Therefore, more and more coal mining technologies and methods are widely used now, and they will also play an increasingly important role.
I. Coal mines in China
Although China is a relatively poor country in terms of oil and natural gas storage, its coal content is
Coal is quite abundant, accounting for about 70% of disposable energy. It can be said that coal has long been the main energy source in China's disposable energy structure. With the continuous expansion of coal mining scale, more and more ecological problems are also highlighted. For example, a large number of buildings and farmland have been destroyed, mountains of gangue, rivers with reduced runoff, groundwater supply sources have dried up seriously, land desertification has intensified, and more and more harmful substances of minerals in groundwater have been caused by coal mining. Therefore, it is particularly important to adopt reasonable mining technology, effective mining methods and preventive measures in coal mining to implement the sustainable development strategy.
Long-term research and development of coal mining and technical reserves are the key work contents to ensure that new mining technologies can keep up with the forefront of industrial science and technology. Positioning the leading core technology in coal mining technology and supporting equipment can not only make technology occupy the commanding heights, but also ensure the survival and development of the coal industry.
Second, new technologies suitable for coal mining in China
Small production capacity and complex geological structure lead to great changes in coal seam occurrence, and a certain number of coal mines with steep coal seams and thin coal seams have brought great difficulties to mining in many areas. Therefore, in order to improve the mine's high yield and efficiency, the analysis and development of mining technology has become very important. For coal mines, single longwall mining method has become increasingly mature, such as caving mining technology, using pseudo-inclined flexible shield support mining method to deal with steep seam, small-stage blasting coal falling and other mining methods are the main development methods at present.
(1) Blasting caving in coal mining technology. First of all, the top-coal caving mining method in sliding supports is mainly aimed at the inclined and steeply inclined coal seam with a thickness of more than 5 m, which is a sliding roof beam composed of roof beam and pillar. The spring steel of the top beam and the front beam must be crossed by the front beam and the rear beam or connected with the guide groove, and there are 2-5 hydraulic single columns with different numbers as their supporting pillars. In addition, the detection beam or cantilever beam can be placed at the front end of the front beam and the tail beam can be placed at the back end of the back beam. This kind of sliding roof beam support not only has the advantages of safe and reliable proportion, but also has the advantages of self-moving, light weight, simple structure, convenient disassembly, low cost and strong adaptability. Therefore, this is a mining technology suitable for wide application in small and medium-sized coal mines. However, as far as the working face is concerned, its low and unstable initial supporting force and working resistance are the main problems faced by sliding supports mining. Second, the second-type steel beam caving mining, which adopts the way of erecting the second-type steel beam and the single hydraulic prop on the second-type steel beam caving coal to the shed for surface support, and adopts blasting and artificial net breaking caving to mine the working face separately. This application is more suitable for township coal mines and areas where the occurrence conditions of coal seams change greatly or the technical level is low.
(2) Pseudo-inclined flexible shield support mining technology. The dip angle of coal seam determines the height of working face section in this mining method. The dip angle of working face will be slowed down by using pseudo-inclined flexible shield support mining method. In addition to the long working face, a series of related characteristics of longwall mining method, such as roadway layout, simple production system and low excavation rate, are all caused by gently inclined coal seams. In order to separate the working space from the goaf, it is extremely suitable to apply this coal mining method to the shield support, which can not only greatly simplify the treatment of complex roof, but also create good conditions for ensuring production safety, so that the coal in the working face slides by itself, thus reducing the labor intensity. This pseudo-inclined flexible shield support mining method is most suitable for mining with dip angle greater than India.
(3) Small bench blasting coal mining technology. The coal mining method of "three noes" working face, which divides the coal body in a section into several sub-sections, is called small-stage blasting coal mining method. For irregular coal seams with mining dip angle greater than 400, thickness of 3.5-7.5m, and roof and floor are not easy to slide down, the most suitable mining technology is small-stage blasting mining method, such as low gas mine. Good safety, simple mining technology and high working efficiency are its advantages, while its relative disadvantages are low recovery rate, complicated ventilation system and difficult air distribution.
(4) Coal mining technology of plough mining method. Plough mining technology not only makes great contribution to the improvement of coal production efficiency, but also is the first successful technology model in the mining of medium and thin coal seams. According to the hardness of coal, the cutting depth of each tool can reach 250 mm. At present, the intelligent drive system is widely used in the face conveyor and coal plough. With the reliable cooperation of the support control system, the full automation of coal mining in the face can be realized smoothly. Compared with drum shearer, plough is relatively simple. The drum shearer needs someone to "level" according to the plane of the flexible armored conveyor, while the plough only needs an endless rope to pull the machine body and weld the guide rail on the flexible armored working face conveyor to make it slide along the guide rail from the end of the working face.
Third, a simple analysis of mining methods
There are more than 100 mining methods, such as open stope mining, filling mining and caving mining, which are the most popular methods based on ground pressure management in mining process. However, when the mining method is not used properly, it will lead to danger and harm, which is briefly analyzed as follows:
(1) has brought inconvenience and difficulty to the mining of ore bodies, and increased the danger of mining operations to a certain extent, which may be caused by the low exploration degree of ore bodies, unclear understanding of the burial situation and scale, wrong layout of stope mining and preparation projects, and lack or lag of mining and preparation projects.
(2) Hidden dangers and dangers such as roof caving, spalling and ground pressure increase in mining operations may be caused by improper mining methods or sequences. This will not only lead to improper mining technology, complicated safety production conditions and inconvenient roof management, but also directly lead to various accidents.
(3) The increase of ground pressure, roof caving, spalling, deformation and even destruction of mining roadway during mining are all caused by unreasonable stope structural parameters and mining sequence.
(4) Because the pedestrian ventilation patio in the working face is not connected with the connecting road, people can only choose to enter the working face from the ore outlet, which cannot guarantee their work safety.
(5) Due to the influence of the crosswalk, it will be difficult for people to pass in the stope with too large spacing.
(6) Because the patio is not connected, the middle and upper roadway is not smooth, the ventilation condition is not smooth, and no fresh air flows into the stope, which is easy to cause personnel smoke poisoning accidents.
(7) Hanging ore at the ore outlet or during ore drawing, causing personnel to fall into the ore flow, causing casualties.
label
The theme of the development of mining science will always revolve around the improvement of coal mining methods and technical progress, because it not only promotes the reform of all aspects of coal mining, but also promotes the realization of high yield, high efficiency, high safety and high reliability of modern coal mining. The combination of coal mining technology and modern high technology is its fundamental way.
refer to
Zhou Siwei. Coal mining method and analysis in inclined seam [J]. New technologies and products in China, 20 10(02).
Lu wenyu. Study on Coal Mining Method in Thin Seam and Optimization of Working Face Length [J]. China University of Mining and Technology (Beijing), 20 10.
He Junfeng, Gao Guangyun, Liu Wensheng. Case Analysis of Coal Pillar Mining Safety [J]. Proceedings of the Second National Symposium on Environmental Geotechnical and Geosynthetics Technology in 2008 (I).
Huang, Zheng Xiangyue and Zheng Weiqiang. Safety problems and prevention of slicing caving mining method [J]. Southern Metals, 20 10(04).
[5] Zhang, Wei, Chen Haijiang. On the fully mechanized top-coal caving face mining technology and measures to improve the recovery rate [J]. Management and technology of small and medium-sized enterprises, 20 10(07).