scholarly journals Thermal infrared characteristics of rock strata fracture in steeply inclined and extra thick coal seam

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 3933-3940
Author(s):  
Yan-Bin Yang ◽  
Feng Cui
Keyword(s):  
Coal Seam ◽  
Infrared Radiation ◽  
Thermal Infrared ◽  
Horizontal Section ◽  
Thick Coal Seam ◽  
Mining Depth ◽  
Movement Rules ◽  
The Relationship ◽  
Thermal Infrared Radiation ◽  
Rock Strata

In view of the complexity of the rules of rock strata fracture in steeply inclined and extra thick coal seam, the mining method of horizontal section top coal caving was put forward. In this paper, the physical similarity simulation model is established to analyze the movement rules of rock strata. The relationship between the form of rock strata fracture and the thermal infrared radiation is analyzed according to studying the characteristics of the thermal infrared radiation temperature of the rock strata fracture. Meanwhile, the changes characteristics of abnormal area of thermal infrared radiation were mastered, and the precursors of thermal infrared radiation of rock strata fracture were predicted. The results showed that the rock strata fracture form of steeply inclined and extra thick coal seam is related to the mining depth.

scholarly journals Study on Roof-Coal Caving Characteristics with Complicated Structure by Fully Mechanized Caving Mining

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Yunpei Liang ◽  
Lei Li ◽  
Xuelong Li ◽  
Kequan Wang ◽  
Jinhua Chen ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Research Work ◽  
Maximum Principal Stress ◽  
Complicated Structure ◽  
Mining Technology ◽  
Thick Coal Seam ◽  
Soft Coal ◽  
Mining Depth ◽  
Arch Forms

With mining technology and mechanization degree being improving, fully mechanized caving mining technology (FCM) has become a main method for thick coal seam extraction in China. However, roof-coal caving characteristics in turn restrict its recovery efficiency, especially for the coal seam with complicated structure (CCS), that is, the coal seam comprises hard or soft coal and gangue. In order to explore the key factors influencing the roof-coal caving and recovery characteristics, related research work has been conducted as follows: firstly, a mechanical model of CCS has been established, which indicates the strength of the coal and gangue will directly affect the roof-coal recovery. Meanwhile, based on the geological settings of Qinyuan coal mine, numerical simulation on roof-coal caving law under different thicknesses of hard or soft coal and gangue has been performed using UDEC software. The results show that the maximum principal stress will increase with the increase of mining depth, making the roof-coal to break easily. Furthermore, the range of the plastic zone of the top coal and the damage degree of the top coal increase with the increase of mining depth. Physical modeling results show that when an extraction-caving ratio is 1, the number of times the coal arch forms is 0.43 at every caving, up to a maximum of 3; the number of times coal arch forms with an extraction-caving ratio of 2 is 4.65 times larger than that with an extraction-caving ratio of 1. The probability of coal arch formation with an extraction-caving ratio of 3 is minimal, about 0.4, which is due to that the arch span is large and the curvature is small, so it is difficult to form a stable arch structure. According to the mechanical characteristics of roof-coal in Qinyuan coal mine, deep-hole blasting technique has been used to reduce the fragments of roof-coal crushed. The results show that this technique can effectively improve the recovery of roof-coal.

scholarly journals Longwave indirect effect of mineral dusts on ice clouds

2010 ◽  
Vol 10 (16) ◽  
pp. 7753-7761 ◽  
Author(s):  
Q. Min ◽  
R. Li
Keyword(s):  
Infrared Radiation ◽  
Mineral Dust ◽  
Dust Cloud ◽  
Thermal Infrared ◽  
Minor Role ◽  
Ice Clouds ◽  
Cloud Systems ◽  
Ice Cloud ◽  
Mineral Dusts ◽  
Thermal Infrared Radiation

Abstract. In addition to microphysical changes in clouds, changes in nucleation processes of ice cloud due to aerosols would result in substantial changes in cloud top temperature as mildly supercooled clouds are glaciated through heterogenous nucleation processes. Measurements from multiple sensors on multiple observing platforms over the Atlantic Ocean show that the cloud effective temperature increases with mineral dust loading with a slope of +3.06 °C per unit aerosol optical depth. The macrophysical changes in ice cloud top distributions as a consequence of mineral dust-cloud interaction exert a strong cooling effect (up to 16 Wm−2) of thermal infrared radiation on cloud systems. Induced changes of ice particle size by mineral dusts influence cloud emissivity and play a minor role in modulating the outgoing longwave radiation for optically thin ice clouds. Such a strong cooling forcing of thermal infrared radiation would have significant impacts on cloud systems and subsequently on climate.

Prediction of Top-Coal Caving and Drawing Characteristics Using Artificial Neural Networks in Extremely Thick Coal Seam

2015 ◽  
Vol 743 ◽  
pp. 612-616 ◽  
Author(s):  
J.H. Yu ◽  
De Bing Mao
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Coal Seam ◽  
Network Model ◽  
Mining Area ◽  
Software Training ◽  
Thick Coal Seam ◽  
Mining Depth ◽  
Training Samples ◽  
Artificial Neural

Based on the feature of large thickness and poor drawing characteristics in extremely thick coal seam top-coal caving method, combined with numerous practical examples analyses, the primarily six factors influence the drawing characteristics were found out which are mining depth, coal seam strength, joint crack development, parting thickness in top-coal, caving ratios, immediate roof filling coefficient. According to 45 typical top-coal caving in extremely thick coal seam samples, the prediction of top-coal caving and drawing characteristics based on artificial neural networks was established and training samples and testing samples was determined. Use SPSS statistical software training the network model. Then select No. 9 coal seam first mining area of Tiaohu mine as the application case. The drawing property was forecast according to the established network model. Application results show that the use of artificial neural networks for top-coal caving and drawing characteristic prediction is effective and feasible.

Localization of lacustrine groundwater discharge (LGD) by airborne measurement of thermal infrared radiation

2013 ◽  
Vol 138 ◽  
pp. 119-125 ◽  
Author(s):  
Jörg Lewandowski ◽  
Karin Meinikmann ◽  
Thomas Ruhtz ◽  
Franziska Pöschke ◽  
Georgiy Kirillin
Keyword(s):  
Infrared Radiation ◽  
Groundwater Discharge ◽  
Thermal Infrared ◽  
Airborne Measurement ◽  
Thermal Infrared Radiation

The possibility of using thermal (infrared) radiation in investigation of the type of stresses in polymers

1974 ◽  
Vol 16 (2) ◽  
pp. 385-393 ◽  
Author(s):  
P.Yu. Butyagin ◽  
V.V. Garanin ◽  
A.R. Kuznetsov
Keyword(s):  
Infrared Radiation ◽  
Thermal Infrared ◽  
Thermal Infrared Radiation

scholarly journals Determination of cyclic filling length in gob-side entry retained with roadside filling and its application

2020 ◽  
Author(s):  
Zizheng Zhang ◽  
Jianbiao Bai ◽  
Xianyang Yu ◽  
Weijian Yu ◽  
Min Deng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Difference Method ◽  
Suggested Method ◽  
Stress Difference ◽  
Thick Coal Seam ◽  
Mechanics Model ◽  
Working Face ◽  
Geological Conditions ◽  
The Relationship

Abstract Gob-side entry retained with roadside filling (GER-RF) plays a key role in achieving coal mining without pillar and improving the coal resource recovery rate. Since there are few reports on the cyclic filling length of GER-RF, a method based on the stress difference method is proposed to determine the cyclic filling length of GER-RF. Firstly, a stability analysis mechanics model of the immediate roof above roadside filling area in GER was established, then the relationship between the roof stress distribution and the unsupported roof length was obtained by the stress difference method. According to the roof stability above roadside filling area based on the relationship between the roof stress and its tensile strength, the maximum unsupported roof length and rational cyclic filling length of GER-RF. Combined with the geological conditions of the 1103 thin coal seam working face of Heilong Coal Mine and the geological conditions of the 1301 thick coal seam working face of Licun Coal Mine, this suggested method was applied to determine that the rational cyclic filling lengths of GER-RF were 2.4 m and 3.2 m, respectively. Field trial tests show that the suggested method can effectively control the surrounding rock deformation along with rational road-in support and roadside support, and improve the filling and construction speed.

scholarly journals Simulation Study of the Roof Fracture Pattern of a Horizontal Sublevel Caving in a Steeply Inclined Thick Coal Seam

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xin Kang ◽  
Sheng-li Yang ◽  
Ping Zhan ◽  
Liang-hui Li
Keyword(s):  
Coal Seam ◽  
Fracture Pattern ◽  
Tensile Failure ◽  
Experimental Simulation ◽  
Mining Equipment ◽  
Horizontal Section ◽  
Thick Coal Seam ◽  
Toppling Failure ◽  
Sublevel Caving ◽  
Simulation Results

Application of a horizontal section top-coal caving in a steeply inclined thick coal seam not only effectively resolves the problem of the large dip angle of the coal seam and slipping and dumping of mining equipment but also significantly reduces the tunnel drivage ratio and improves the extraction yield. In addition, it allows for a safe and efficient mining from a steeply inclined thick coal seam. In this paper, the roof fracture pattern of a steeply inclined thick coal seam has been studied by a similar simulation experiment. The results of the simulation are consistent with those of the numerical calculations, thus verifying the accuracy of the simulation. The experimental simulation results show that the roof can form a step-like toppling failure pattern after drawing the coal, and it is difficult to release a triangular coal mass near the floor, which is the main concentration area of coal loss. The numerical simulation results show that, with the excavation of the coal seam, the rock mass around the goaf produces plastic failure, and the damage is mainly concentrated in the roof area. The upper part of the goaf mainly shows a tensile failure, while the other areas mainly show yield failure.

Water Saturation Effects on Thermal Infrared Radiation Features of Rock Materials During Deformation and Fracturing

2020 ◽  
Vol 53 (11) ◽  
pp. 4839-4856 ◽  
Author(s):  
Xin Cai ◽  
Zilong Zhou ◽  
Lihai Tan ◽  
Haizhi Zang ◽  
Zhengyang Song
Keyword(s):  
Infrared Radiation ◽  
Water Saturation ◽  
Thermal Infrared ◽  
Rock Materials ◽  
Saturation Effects ◽  
Thermal Infrared Radiation

Detectors Of Thermal Infrared Radiation

1988 ◽  
Author(s):  
C T. Elliott
Keyword(s):  
Infrared Radiation ◽  
Thermal Infrared ◽  
Thermal Infrared Radiation
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