Evaluation of Safe Mining on Confined Water of No. I1 Coal in Micun Coal Mine

Fesibility Study on Mining Two-Confined-Water Coal Seam in North-China-Type Coalfield - Taking Shuangliu Coal Mine as the Example

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.807-809.2378 ◽

2013 ◽

Vol 807-809 ◽

pp. 2378-2388 ◽

Cited By ~ 2

Author(s):

Hua Wang ◽

Zhi Qiang Liu ◽

Hong Guang Ji ◽

Jin An Wang ◽

Guo Dong Zhao ◽

...

Keyword(s):

Coal Seam ◽

Coal Mine ◽

Water Inrush ◽

Damage Zone ◽

Physical And Mechanical Properties ◽

Shanxi Province ◽

Confined Water ◽

Coal Seams ◽

Zone Water ◽

Lower Group

Shuangliu mine is located in the middle of Hedong coalfield, Lvliang City , Shanxi Province. It is one of the typical NorthChinaType coalfields. The upper strata of the lower-group coal seams (8#, 9# seam) have several thin-layer limestones of the Taiyuan Formation, and the underlying strata of the lower-group coal seams have thick Ordovician limestone. Water inrush accident has ever happened in other mine in its vicinity. Therefore, whether the lower-group coal seams could be mined safely is related to the medium-and long-term program and sustainable development of Shuangliu Mine. Based on experimental study of physical and mechanical properties of main rocks of the roof and floor of the under-group coal seams, and the application of "Up Three Zone" Theory of coal seam roof (the caving zone, water flowing fractured zone and bending sinking zone), "Down Three Zone" Theory of coal seam floor (mining damage zone, water-resisting zone, water-conductive zone) and Water inrush coefficient Theory, we analyzed the water inrush risk and divided potential dangerous subareas of water inrush from coal seam floor while mining lower-group coal seams. The research findings can provide scientific basis for mining design and safe mining of lower-group coal seams in Shuangliu Coal Mine.

Download Full-text

Explored the Fully-Mechanized Caving Mining of Water Flowing Fractured Zone

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.450-451.1253 ◽

2012 ◽

Vol 450-451 ◽

pp. 1253-1256

Author(s):

Qiang Li ◽

Chun Xi Luo ◽

Ling Hui Meng

Keyword(s):

Coal Mine ◽

Fractured Zone ◽

Safe Mining

In one class mining under water, the height of water flowing fractured zone can realize safe mining is the main parameters. This paper is a stage summary and explored in Tiefa coal group Co., LTD. KangPing coal mine about water flowing fractured zone.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Download Full-text

Research on the Influence of Slurry Filling on the Stability of Floor Coal Pillars during Mining above the Room-and-Pillar Goaf: A Case Study

Geofluids ◽

10.1155/2020/8861348 ◽

2020 ◽

Vol 2020 ◽

pp. 1-21

Author(s):

Zhu Li ◽

Guorui Feng ◽

Jiaqing Cui

Keyword(s):

Plastic Zone ◽

Coal Mine ◽

Body Height ◽

Coal Pillar ◽

Northwest China ◽

Engineering Practice ◽

Working Face ◽

The Stability ◽

Safe Mining ◽

Upward Mining

Room-and-pillar mining is a commonly used mining method in previous practice in northwest China mining area. Due to priority selection of high-quality resources, coal mines in northwest China generally have to face upward mining above goaf. Thus, the stability of a floor coal pillar influenced by mining activities plays an essential role in upward mining above goaf. The results indicated that a floor coal pillar kept stable before coal excavation in the no. 6107 working face in the Yuanbaowan coal mine; however, the plastic zone in the floor coal pillar expanded sharply and the elastic core zone reduced suddenly on the influence of abutment pressure. Finally, the floor coal pillar supported failure. Accordingly, the paper proposed a floor coal pillar reinforcing technique through a grout injection filling goaf area. As physically limited by a different-height filling body on the double sides, the plastic zone scope and horizontal displacement and loading capacity of the floor coal pillar were studied, working out that the critical height of the filling body should be about 6 m which can ensure safe mining when upward mining above goaf. Case practice indicated that the fractures induced by mining in the floor coal pillar, filling body, and floor can be restrained effectively when the filling body height is 6 m, which can ensure floor coal pillar stability and safe mining of the no. 6107 working face in the Yuanbaowan coal mine. The research can provide theoretical and technical guidance for upward mining above goaf and have a critical engineering practice value.

Download Full-text

Research on Seepage Properties and Pore Structure of the Roof and Floor Strata in Confined Water-Rich Coal Seams: Taking the Xiaojihan Coal Mine as an Example

Advances in Civil Engineering ◽

10.1155/2018/9483637 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Hailong Li

Keyword(s):

Coal Seam ◽

Coal Mine ◽

Water Storage ◽

Effective Porosity ◽

Storage Space ◽

Confined Water ◽

Fractured Aquifer ◽

Coal Seams ◽

Fractured Aquifers ◽

Fissure Water

During the construction and exploitation process in the Xiaojihan coal mine, which is located in Yulin of northern Shaanxi, we find a special hydrogeological phenomenon that coal seam is acted as a confined fractured aquifer. The water-rich coal seam has natural fissures which are confined with water storage. However, the water comes from the static and original reserves in coal seams, which have a weak link to other aquifers in the roof and floor strata. It indicates that the roof and floor strata provide a natural waterproof barrier for the fissure water in the coal seam, resulting in a relatively closed storage space of confined water. In order to further investigate the critical function that mechanical properties of permeability play in the confined fractured aquifer, the rock complete stress-strain permeability test and pore development structure test are carried out with rock samples of the roof and floor strata in this field. Results are as follows: (1) coal seams of Xiaojihan coal mine are confined fractured aquifers, the fissure confined water in coal seams has a strong relationship with total stress-strain permeability and development characteristics of the pore structure of the roof and floor strata. (2) The permeability of the roof and floor strata is extremely low, when the strata is less than 30 meters away from the coal seam with the magnitude order remaining less than 10−12 m/s. If they are closer to the coal seam, the watertightness and plasticity of the strata will be stronger, and the antidestructive capability of the strata during the distortion process will be also increased, resulting in the larger strain for the formation of macroscopic water-conducting fissures. The roof and floor strata effectively cut off the hydraulic connection between the fissure water in the coal seam and other aquifers, which ensure the coal seam acts as water storage space of confined fractured aquifers. (3) For undeveloped fissures, the effective porosity is less than 2% of the roof and floor strata which are less than 30 meters away from the coal seam, and particularly, this index is less than 1% of the strata within 20 meters away from the coal seam, indicating that the strata have good water resistance. When the distance between the roof strata and the coal seam is greater than 40 meters, the effective porosity has a large fluctuation, and the effective porosity of the partial strata is greater than 10%, reflecting that the rock strata fissure has been well developed. It should be attached great importance to prevent water-conducting fissures from getting hydraulic connection with the fractured water-rich coal seams and other aquifers of the roof and floor, so as to reduce the risk of mining water hazards.

Download Full-text

Feasibility Analysis of Safety Mining Underlying Limestone Water in Yuandian Coal Mine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.256-259.454 ◽

2012 ◽

Vol 256-259 ◽

pp. 454-457

Author(s):

You Ling Fang ◽

Yu Long Chen

Keyword(s):

Coal Seam ◽

Coal Mine ◽

Mining Area ◽

Feasibility Analysis ◽

Targeted Prevention ◽

Limestone Aquifer ◽

Mining Conditions ◽

Prevention And Treatment ◽

Water Filling ◽

Safe Mining

The No.10 coal seam in the first mining area of Yuandian Coal Mine lies in Taiyuan Group limestone aquifer with rich water, the underlying limestone water is an important danger for mine water-filling. To ensure the safety of mining, it is necessary to study and analyze the mining conditions. On this basis, with the design of targeted prevention and treatment of water, we achieve the purpose of safe mining.

Download Full-text

Research on determining the safe mining depth in special geological conditions of Mong Duong coal mine

Journal of Mining and Earth Sciences ◽

10.46326/jmes.2021.62(5).07 ◽

2021 ◽

Vol 62 (5) ◽

pp. 76-83

Author(s):

Chung Van Pham ◽

Dac Manh Phung ◽

Ha Thu Thi Le ◽

Trong Gia Nguyen ◽

Trung Thanh Ngo ◽

...

Keyword(s):

Coal Mine ◽

Underground Mining ◽

Water Bodies ◽

Coal Seams ◽

Mining Depth ◽

Geological Conditions ◽

Mineral Loss ◽

Safe Mining

The displacement and deformation of strata due to underground mining is one of the factors that negatively affect the safety of production activities. The strata displacement and deformation depend on many factors such as mining geological conditions, safe mining depths, and mining technologies. The determination of the safe depths is important for calculating the size of safety pillars to minimize mineral loss. To date, there have been many studies to determine safe mining depths under normal geological conditions. However, not much research has been conducted to determine safe mining depths with special geological conditions such as many folds, breaks, faults, and under water-bearing objects. This research introduces a method to determine the safe mining depths for the reservoir set in special geological conditions with folds and excavating several seams under water bodies. The proposed method employs the principle of the similar geological zone theory to calculate the safe mining depths. The method is applied to the Mong Duong coal mine, with three coal seams numbered 5, 6, and 7 with the depth of 210, 180, and 136 m, respectively. The results of mining depths safe obtained H5= 240m, H6 =192m, H7= 136m, respectively.

Download Full-text