Enriched fault in the coal-containing formation, fold; Coal Seam, fluctuation tendency, was syncline anticline; large mine coal seam thickness variation, called Coal Mine unstable. Coal mines in Fujian Province are basically all unstable coal seam mines. The use of suitable mining technology for unstable coal seam mines is an important issue that is often encountered in the coal mining industry, especially in coal-deficient areas. This article talks about the shallow knowledge of the unstable coal seam mining technology. 2 mining technology discussion 2.1 Ways of development The coal seams in Fujian Province are basically inclined and steeply inclined coal seams, and they are all distributed in the rolling hills of the mountains. The surface slopes are large and the valleys are developed. The surface space of the ground industrial squares that can be used as mines is limited. Therefore, the development of its mine should be selected in the following ways: (1) Pingshuo; (2) Pingyi--dark inclined well; (3) inclined well. Coal seams in Fujian Province are distributed in mountainous areas. When selecting the mode of development, the surface space of the mine floor industrial plaza within the scope of the mine field should be considered first. Under the conditions of its permission, it is preferred to choose the mode of development. According to the division of mining levels, flat rafts are arranged separately. The position of the flat seam should be chosen such that the flatness is as short as possible to expose the position of the coal seam. When the surface space conditions available for use as a mine ground industrial plaza are limited, the development of a flat shovel-dark or inclined well is considered. The main reference factor for the choice of these two modes of development is the complexity of the coalbed geological conditions in the minefield. If the geological conditions of coal seams are relatively complex, it may be considered to adopt the development method of Pingyi--dark inclined wells. This development method can achieve low initial investment, high production, quick effect, and make full use of Pingshu to expose the geological conditions of coal seams, and master the geological data of coal seams within the richer mine field, which is conducive to the correct selection of deep horizontal inclined wells. position. If the geological conditions of the coal seam are relatively low and the coal-bearing stratum is relatively stable, the inclined well development method can be adopted. Although the pioneering method has more initial investment, it has less total investment and is conducive to centralized production. 2.2 mining process Because the unstable coal seam has many geological structures and large changes in the thickness of the coal seam, the spatial conditions of the mining face are changed frequently, and it is difficult to meet the operation of the shearer. The space conditions of the mining face are not demanding and flexible. High sex, therefore, the choice of blasting process is more reasonable. According to the occurrence of different coal seams, the following methods of arranging the working face can be selected. (1) Short wall method In the coal seam with relatively stable coal thickness and less geological structure, the short-walled layout can be used for the mining face. The wall length is about 60m. The return air duct is arranged on the working surface, and the transport lane is arranged in the lower part. Advance in the direction of the vertical transport lane. (2) Medium-deep hole blasting method In the coal seam dip angle is large, the top and bottom plates are relatively stable, the roof is not easy to fall, slowly sinking, the bottom plate is a smooth coal seam or a "chicken nest"-like coal package, using medium-deep hole blasting method. In the set mining section, the upper part is arranged with the return air passage, the lower part is arranged with the transport lane, and the contact eyes are digged in the coal seam along the inclined direction and the pseudo oblique direction to divide the coal seam into a diamond shape. The distance between the two rhombic edges parallel to the direction of the propensity is suitable for the depth of the best effect of the medium-deep hole blasting by the technical ability possessed by the mine, generally about 20m, and the length of the rhombic parallel to the orientation direction should be about 25m. The mining sequence is to pick up the coal seams that are divided into diamond shapes from bottom to top. The entire work surface is advanced perpendicular to the transport lane. (3) Slope method In the steeply inclined coal seam, the return air duct is arranged on the working surface, the transport lane is arranged in the lower part, and the main slope of the pseudo-slanting excavation is communicated with the upper return airway in the coal seam along the boundary of the coal seam, and the coal seam is inclined on the main slope. In the direction, several sub-slopes are drilled separately, and the sub-slopes are communicated with the former main slope to divide the coal seams in the mining section into several block sections, and the coal seams of the divided blocks are successively recovered from top to bottom. The entire working surface is advanced backwards perpendicular to the transport lane. The layout of the mining roadway (cutting eye, contact eye, main slope, W-slope) of the above-mentioned several mining methods should use coal seam geological conditions such as coal thickness variation limit and geological structure edge as much as possible to divide the discontinuous coal body. The thickness and the inclination are relatively stable and the continuous block segments are compared, and then the corresponding coal mining method is selected for specific conditions. Due to the instability of the coal seam, the appropriate coal mining method should be selected according to the specific occurrence conditions of the coal seam. Even in the same mining face, do not simply choose a coal mining method, but often it is best to use a combination of multiple coal mining methods. 2.3 Mining area roadway layout According to the characteristics of coal mines in Fujian Province, which have thin coal seams, many layers, and small interlayer spacing, it is more appropriate to select multiple coal seams for the mining area layout of the mine. In the multi-coal layer, the bottom of the coal seam at the bottom of the coal seam is selected to be placed uphill. The position of the uphill should be placed as far as possible parallel to the axis of the coal seam and the anticline structure. The horizontal depth of mining is generally about 100mm. The length of the mining area should use the trending fault of the stratum as the boundary of the mining area. Generally, the length of the single wing is about 500m, and the vertical height of the mining section is about 30m. The transport lane of the mining section should be arranged as far as possible to the shaft section of the stratum direction and the anticline structure. For coal seams with coal seams with a spacing of about 10 m, the transportation lanes in the mining section can be combined and arranged along the coal seams of the opposite bottom layer, and then the upper coal seams are communicated by means of excavating the reverse eye grooves, and the upper coal seams are advanced. The method of simultaneous mining of two coal seams of 20 m in the lower coal seam is carried out. In addition to the coal mining excavation in the section of the mining section, the location of the lanes in other mining areas should be selected as much as possible in the section structure provided in the geological data, so that the excavated roadway can serve the production area and can also be used as a roadway. Find out the geological conditions of the coal seams of the mine to provide more abundant and detailed raw materials, so as to select mining technology more scientifically and rationally. 3 Conclusion The fundamental characteristics of the geological conditions of unstable coal seams are variable. Therefore, we should change our strain. Under the premise of ensuring safe production and obtaining the best economic benefits, the selection of mining technology should be specifically analyzed according to specific conditions, tailored to local conditions, scientific and reasonable. Flyknit Shoes,Flyknit Shoes Mens,Flyknit Shoes Womens,Flyknit Running Shoes Shangqiu JIAYING SHOES CO.,LTD. , https://www.jiayingshoes.com
Discussion on mining technology of unstable coal seam mine
1 Introduction