scholarly journals Overview of Solid Backfilling Technology Based on Coal-Waste Underground Separation in China

2019 ◽  
Vol 11 (7) ◽  
pp. 2118 ◽  
Author(s):  
Qiang Zhang ◽  
Jixiong Zhang ◽  
Zhongya Wu ◽  
Yang Chen
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
Surface Subsidence ◽  
Separation Method ◽  
Dense Medium ◽  
Research Progress ◽  
Coal Waste ◽  
Gas Extraction ◽  
Water Separation ◽  
Waste Separation

China is the world’s largest coal producer country. However, large-scale coal mining has led to severe environmental pollution issues such as surface subsidence and gangue piling up. The gangue discharging amount has ranked the first in the world and coal mine enterprises are facing enormous discharging reduction pressure. This paper summarizes the research progress of the solid backfilling mining technology and then illustrates the realistic demands and significance of implementing underground coal-waste separation. It also focuses on the technical principles, systems and key equipment of the common underground coal-waste separation methods, such as the selective crushing method, the dense medium shallow groove method, the vibro-assisted jigging method and full-size water separation method and ray identification method. In addition, the selection steps of underground coal-waste separation method, the design process of large section separation chamber and the design principle of separation and backfilling system are proposed, finally, the mining-separating-backfilling + X for coal mining is put forward. By combining the technology of mining-separating-backfilling with other technologies, such as gob-side entry retaining with non-pillar mining, gas extraction, solid waste treatment, water protection mining, mining under buildings, railways and water bodies, the integrated mining methods, mining-separating-backfilling + setting pillars, gas drainage, treatment, protection and prevention methods are formed. It also introduced the ‘mining-separating-backfilling + gas extraction’ technology’s whole idea, system arrangement, separation equipment and practical engineering application effects based on the specific engineering case of pingmei no. 12 coal mine. The results indicate that the integration of underground coal-waste separation and solid backfilling technology could achieve gangue discharging reduction, underground washing and surface subsidence control. It is effective at realizing green mining.

scholarly journals Surface Subsidence Prediction Method for Coal Mines with Ultrathick and Hard Stratum

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Hongkai Han ◽  
Jialin Xu ◽  
Xiaozhen Wang ◽  
Jianlin Xie ◽  
Yantuan Xing
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
Prediction Method ◽  
Prediction Equation ◽  
Arbitrary Cross Section ◽  
Surface Subsidence ◽  
Strong Impact ◽  
Subsidence Prediction ◽  
Movement Characteristics ◽  
Mining Condition

Overburden conditions consisting of ultrathick and hard stratum (UTHS) are widespread in China and other countries, but existing surface subsidence prediction methods ignore the strong impact of UTHS on surface subsidence. They are thus not applicable for surface subsidence prediction for coal mining with the presence of UTHS. We conducted actual measurements of surface and UTHS subsidence in the Tingnan Coal Mine. The results showed that under the UTHS mining condition, the required gob dimension is much larger than the empirical value when the surface reaches sufficient mining and that the actual measured maximum value of surface subsidence is much smaller than the empirical value. The UTHS subsidence is approximately equal to the surface subsidence. The movement of UTHS has a strong impact on surface subsidence and has a controlling function for it. It was proposed that surface subsidence could be approximately predicted by calculating the UTHS subsidence. The UTHS movement characteristics were studied using Winkler’s theory of beams on an elastic foundation, the subsidence prediction equation of the main sections in the strike and dip directions was obtained under different mining dimensions, and the subsidence prediction equation of any arbitrary cross section parallel to the two main sections was established. Then, the surface subsidence prediction method for coal mining with the presence of UTHS was developed, and the influences of UTHS thickness, strength, and layer position on the surface subsidence were discussed. The Tingnan Coal Mine was taken as an example, and the subsidence curves of the strike and dip main sections were calculated using different mining dimensions. Subsequently, the surface subsidence after the mining of working faces 204, 205, 206, and 207, respectively, was predicted, and the prediction method was verified by comparing the results with the measured surface subsidence results of working faces 204, 205, and 206.

The Research Progress of Coal and Gas Co-Mining

2012 ◽  
Vol 524-527 ◽  
pp. 489-493 ◽  
Author(s):  
Li Ming Ying ◽  
Jie Chen ◽  
Chao Du ◽  
Lin Xiang Pang ◽  
Yong Jiang Wen
Keyword(s):  
Coal Mine ◽  
Greenhouse Gas Emission ◽  
Research Progress ◽  
Coal Bed ◽  
Gas Extraction ◽  
Gas Emission ◽  
Extraction Technology ◽  
Pressure Relief ◽  
Adjacent Layer ◽  
Improve Energy Efficiency

The coal bed methane is an important part of the Chinese energy. To finding some effect ways to collect gas during the coal mining process will increasing the using rate of coal mine and reducing greenhouse gas emission. The most effective way is coal and gas co-mining, and the main technology of the coal and gas co-mining are gas pre-extraction before mining, gas extraction of pressure relief, gas extraction of adjacent layer, gas extraction of goaf and top fractured zone, Gas extraction of excavation roadway and so on. Based on the technique system of coal and gas co-mining and the key problems existing in coal and gas extraction technology, to improve energy efficiency and reduce coal mine disaster.

Clean Mining Technology of Waste Not Discharged From Coal Mine

2012 ◽  
Vol 524-527 ◽  
pp. 552-556
Author(s):  
Dong Sheng Zhang ◽  
Tao Dong ◽  
Gang Wei Fan
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
The Other ◽  
Mining Technology ◽  
Mining Technique ◽  
Key Points ◽  
Mining Face ◽  
Coal Pillars ◽  
Waste Separation

In order to solve the problem of heaping waste in aboveground, a cleanly mining technique of waste not discharged from coal mine was proposed. It includes two key points as follows: one is waste separation underground; the other is mining technique with preset packing body of waste without coal pillars. After the waste from the coal mining face had been separated out, the waste was used to preset packing body of waste. It is able to decrease stress of mine hoisting. The technique has been successfully used in Gaozhuang Coal Mine.

scholarly journals Fracture evolution and gas transport laws of coal and rock in one kilometer deep coal mine with complicated conditions

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 907-915
Author(s):  
Jianguo Zhang ◽  
Man Wang ◽  
Yingwei Wang
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Coal Mine ◽  
Fracture Zone ◽  
Gas Flow ◽  
Gas Transport ◽  
Enhancement Effect ◽  
Gas Extraction ◽  
Coal Seams ◽  
Long Distance

As coal mining gradually extends deeper, coal seams in China generally show high stress, high gas pressure and low permeability, bringing more difficulty to coal mining. Therefore, in order to strengthen gas extraction, it is necessary to carry out reservoir reconstruction after deep coal seams reached. In this paper, the distribution and evolution laws of fracture zone overlaying strata of J15 seam in Pingdingshan No. 10 coal mine after excavation were studied by combining similar simulation and numerical simulation, meanwhile, the gas transport law within fracture zone was numerically simulated. The results show that the fracture zone reaches a maximum of 350 mm in the vertical direction and is 75 mm away from W9,10 coal seams in vertical distance. Since W9,10 coal seams are in an area greatly affected by the bending zone of J15 coal seam under the influence of mining, the mining of J15 coal seam will exert a strong permeability enhancement effect on W9,10 coal seams. The J15 coal seam can act as a long-distance protective layer of W9,10 coal seams to eliminate the outburst danger of the long-distance coal seams in bending zone with coal and gas outburst danger, thereby achiev?ing safe, productive and efficient integrated mining of coal and gas resources. The gas flux of mining-induced fractures in the trapezoidal stage of mining-induced fracture field is far greater than that in the overlaying stratum matrix. The horizontal separation fractures and vertical broken fractures within the mining-induced fracture field act as passages for gas-flow. Compared with gas transport in the overlaying stratum matrix, the horizontal separation fractures and vertical broken fractures within the mining-induced fracture field play a role in guiding gas-flow. The research results can provide theoretical support for the arrangement of high-level gas extraction boreholes in roof fracture zones.

scholarly journals Directional Hydraulic Fracturing (DHF) of the Roof, as an Element of Rock Burst Prevention in the Light of Underground Observations and Numerical Modelling

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 562
Author(s):  
Marek Jendryś ◽  
Andrzej Hadam ◽  
Mateusz Ćwiękała
Keyword(s):  
Rock Mass ◽  
Hydraulic Fracturing ◽  
Coal Mining ◽  
Rock Burst ◽  
Coal Mine ◽  
Seismic Activity ◽  
Black Coal ◽  
Directional Hydraulic Fracturing ◽  
Before And After ◽  
The Face

The following article analyzes the effectiveness of directional hydraulic fracturing (DHF) as a method of rock burst prevention, used in black coal mining with a longwall system. In order to define changes in seismic activity due to DHF at the “Rydułtowy” Black Coal Mine (Upper Silesia, Poland), observations were made regarding the seismic activity of the rock mass during coal mining with a longwall system using roof layers collapse. The seismic activity was recorded in the area of the longwall itself, where, on a part of the runway, the rock mass was expanded before the face of the wall by interrupting the continuity of the rock layers using DHF. The following article presents measurements in the form of the number and the shock energy in the area of the observed longwall, which took place before and after the use of DHF. The second part of the article unveils the results of numerical modeling using the discrete element method, allowing to track the formation of goafs for the variant that does not take DHF into consideration, as well as with modeled fractures tracing DHF carried out in accordance with the technology used at “Rydułtowy” coal mine.

scholarly journals Experimental Study on the Cement-Based Materials Used in Coal Mine Gas Extraction for Hole Sealing

ACS Omega ◽  
2021 ◽  
Author(s):  
Jianhua Fu ◽  
Dengke Wang ◽  
Xuelong Li ◽  
Zhiming Wang ◽  
Zhengjie Shang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Coal Mine ◽  
Gas Extraction ◽  
Coal Mine Gas ◽  
Cement Based Materials ◽  
Mine Gas ◽  
Materials Used

Impacts of Coal Mining on the Aboveground Vegetation and Soil Quality: A Case Study of Qinxin Coal Mine in Shanxi Province, China

2011 ◽  
Vol 39 (3) ◽  
pp. 219-225 ◽  
Author(s):  
Guo Donggan ◽  
Bai Zhongke ◽  
Shangguan Tieliang ◽  
Shao Hongbo ◽  
Qiu Wen
Keyword(s):  
Coal Mining ◽  
Soil Quality ◽  
Coal Mine ◽  
Shanxi Province

Principle of Well-Net Design for Coalbed Methane Exploitation in Coal Mine Area

2014 ◽  
Vol 543-547 ◽  
pp. 3967-3973
Author(s):  
Bao Shan Han
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
Coalbed Methane ◽  
Design Theory ◽  
Surface Condition ◽  
Coal Pillar ◽  
Negative Influence ◽  
In Situ Stress ◽  
Well Location

There are abundant CBM (Coalbed Methane) in China. These CBM has caused a remarkable problem to the coal-mining in China. In order to improve the structure of Chinese energy and eliminate the risk of coal mine gas, the relevant industries and sections have implemented many explorations in CBM enriched areas. With great achievements, there are many important problems in the actions of CBM exploitation. The disadvantageous interaction of the surface CBM well and the later coal mining has been ignored at all. There are many disadvantages and defects. To solve these problems and eliminate or weaken the disadvantageous, the scientific and reasonable design of surface CBM well location is an important step. With the thinking of surface condition, coal mining plan, the arrangement of coal mine laneway, the direction and scale of the in-situ stress, and thinking more about the negative influence to and of surface CBM well, according to the theories of mining dynamics, mining engineering, mining geomechanics, and the CBM engineering, the design theory of the surface CBM well net can be studied. Finally, the arrangement principle of CBM product well in coal field is presented. The existing or future coal pillar will be a critical location for the surface CBM well location.

Can Government Regulate Safety? The Coal Mine Example

1980 ◽  
Vol 74 (3) ◽  
pp. 745-756 ◽  
Author(s):  
Michael S. Lewis-Beck ◽  
John R. Alford
Keyword(s):  
Federal Government ◽  
Coal Mining ◽  
Coal Mine ◽  
Occupational Safety ◽  
Interrupted Time Series ◽  
Target Population ◽  
Interrupted Time Series Analysis ◽  
Ample Evidence ◽  
Safety And Health ◽  
Mining Safety

With the 1970 passage of the Occupational Safety and Health Act (OSHA), federal regulation reached the American workplace. Given the newness of the legislation, any firm conclusion on its effectiveness seems premature. However, there is ample evidence on federal safety regulation of a specific workplace: the coal mine. The federal government has been directly involved in coal mining safety for over 35 years, operating under three major pieces of legislation, enacted in 1941, 1952, and 1969. Opposing opinions regarding the effect of this legislation can be grouped into three categories: radical, reactionary, and reformer. A multiple interrupted time-series analysis indicates that, in fact, the 1941 and 1969 regulations significantly reduced the fatality rate in coal mining. Certain conditions seem related to the effectiveness of this safety legislation: birth order, provisions, enforcement, target population, and goals. The first two conditions would appear to work for the success of the OSHA, the latter three conditions to work against it.

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