Sandstone Coal Mine Roof

Sandstone Coal Mine Roof

Weak sandstone mine roofs, Coal, Kentucky Geological ...

Definition and formation: Sandstone is a common roof rock above many coal beds. It is especially common beneath paleochannel deposits, and transitional with some stackrock deposits. Thick-sandstone mine roofs commonly offer good roof conditions. Sandstone tops may have local weaknesses along bedding, however, which can lead to roof falls.

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Piezoelectric effect and ignition properties of coal mine ...

2021-4-15  The coal mine roof sandstone in air showed that there will be luminescence in the process of rock fracturing under load, and the red light intensity was the strongest in the recorded visible light. This indicates that the luminescence phenomenon in the rock fractures was closely related to the nature of the environmental medium; that is, the ...

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Discharge and ignition characteristics from indentation ...

2021-5-1  The electricity generation and discharge characteristics of the roof sandstone of the Renlou coal mine described in Section 3 comprehensively demonstrate that the electrical effect generated by the roof sandstone can ionise the combustible gas and cause a gas explosion. Fig. 12 shows the electric spark generated during the cracking of the ...

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Study on Water Enrichment Prediction of Coal Roof ...

Sandstone roof water is the direct water-filling resource of coal mining, which has a great effect on the mine production. However, because of the unequal enrichment of Sandstone roof water, it is difficult to prevent and treat sandstone roof water. In order to study the water enrichment of coal roof sandstone, take 8# coal seam of ZhangBei coal mine as an example.

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Experimental study on characteristics of surface potential ...

2020-3-5  Fig. 1 shows the testing system of the mechanical–electrical characteristics of coal mine roof sandstone; the system mainly includes the mechanical testing system (MTS) as well as the current and voltage monitoring and recording system. For the uniaxial compression experiment, an MTS-C64.605 press is used; its computer system, which could monitor the stress and strain changes in the loaded ...

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Fracture failure analysis of hard–thick sandstone roof and ...

2015-8-1  Datong coalfield, is situated in a northeast-trending syncline in the northern of the North China Block and the Shanxi Platform. Many thick coal seams in the Datong coalfield are of hardness higher than 2.5, and their roofs are of a hardness higher than 7.0, i.e., a configuration referred to as “double hard coal seam” .Tashan Coalmine (TSCM) is a typical example, the hard–thick sandstone ...

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Discharge and ignition characteristics from indentation ...

2021-2-5  Discharge and ignition characteristics from indentation fracture of coal mine roof. Fuel ( IF 6.609 ) Pub Date : 2021-02-05 , DOI: 10.1016/j.fuel.2021.120208. Yi Lu, Min Li, Deming Wang, Xingyu Shi, He Li, Yunfei Zhu, Qing Ye, Jiexin Lu. Electric effects are generated during the deformation and fracture of coal mine roof sandstones.

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Effect of Temperature on Macroscopic and Microscopic ...

2021-10-23  Sandstone is often encountered during deep underground engineering activities such as tunnelling, geothermal exploitation and oil drilling, and especially in coal mines, where the roof and floor of the coal seams are mostly sandstone (Zhu et al. 2016; Zhang et al. 2010). Moreover, tunnels and monuments are at risk of fire, while coal mines are ...

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Application of coal mine roof rating in Chinese coal mines ...

2018-5-1  1. Introduction. Roof falls continue to be one of the greatest hazards faced by underground coal miners especially in Chinese coal mines , , .Even though an individual roof fall accident could cause less injuries or fatalities than gas explosion, the total fatalities or damage to facilities caused by roof falls are more than the other type of mine accidents , , , .

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Mine Roof Condition and the Occurrence of Roof Falls in ...

2006-7-7  ABSTRACT. Mine roof fall characteristics of 250 falls in 5 different room-and-pillar coal mines, located in Pike, Martin, and Floyd counties, Kentucky, were investigated to determine the relationship of selected parameters associated with roof failure and the assumed condition of the mine roof before failure. The selected parameters used in

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Study on Water Enrichment Prediction of Coal Roof ...

Sandstone roof water is the direct water-filling resource of coal mining, which has a great effect on the mine production. However, because of the unequal enrichment of Sandstone roof water, it is difficult to prevent and treat sandstone roof water. In order to study the water enrichment of coal roof sandstone, take 8# coal seam of ZhangBei coal mine as an example.

Read More
Piezoelectric effect and ignition properties of coal mine ...

In the process of roof sandstone rupture, instantaneous discharge formed owing to the piezoelectric effect, which could break through the air. Considering the Babao coal mine gas explosion accident, the high quartz content of the roof rock reached a certain compressive strength and experienced simultaneous stress mutation, exhibiting ...

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Mine Safety and Health Administration (MSHA) - Coal

2019-9-5  The immediate roof in the mine varies from shale, up to 25 feet thick, to sandstone. The immediate roof in the No. 4 section, the area of the accident, was sandstone. The sandstone unit above the Coalburg seam has a published Coal Mine Roof Rating (CMRR) of 96, indicating a very competent immediate roof. The mine floor consists of shale.

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Coal Mine Geology In The U.S. Coal Fields: A State-Of

2012-8-30  details went unnoticed until the mine hit a sandstone channel, fault, or poor roof conditions which necessitated the operator to aimlessly turn headings left and right without success until the area had to be abandoned. Other mine operators were made aware of the benefits of underground mapping and geologic forecasting techniques

Read More
Mine Roof Condition and the Occurrence of Roof Falls in ...

2006-7-7  ABSTRACT. Mine roof fall characteristics of 250 falls in 5 different room-and-pillar coal mines, located in Pike, Martin, and Floyd counties, Kentucky, were investigated to determine the relationship of selected parameters associated with roof failure and the assumed condition of the mine roof before failure. The selected parameters used in

Read More
Analysis of Roof Failure at the Intersections on a Coal Mining

The objective of this paper is to understand the behavior of the roof and the cause of roof failure of a coal mining. Eleven roof falls occurred in the mine section in sequence. All the roof falls were surveyed, and the geological features were determined which include rock type, mechanical properties, and thickness. The immediate roof thickness was interpolated to determine the cause of the ...

Read More
The Characteristics of Roof Breaking and the Law of

2020-7-31  In view of the characteristics of large overburden movement space, strong mining disturbance and difficult to determine the initial pressure step distance of the roof in fully mechanized top-coal caving face with large mining height, the working face 101 of a coal mine is taken as the engineering background, through theoretical analysis, numerical simulation and field measurement methods are ...

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Longwall Shield Recovery Using Mobile Roof Supports

2012-8-30  Mine, this shale unit can either be laminated, sandy, or nonexistent (replaced by a sandstone scour). These fluctuations explain the range in Coal Mine Roof Rating values from 44 to 71 (Molinda and Mark, 1994). These values indicate that the immediate roof rock is of moderate strength to strong.

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Causes of Falls of Roof - Council for Scientific and ...

2021-9-11  In general, roof falls occurred in areas where the roof rock was found to be less competent in terms of rock mass rating systems. It was concluded that the Coal Mine Roof Rating (CMRR) system developed by NIOSH in the USA held promise for application in South Africa and should be

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Our Coal and Our Clients – Kestrel Coal

Kestrel produces high energy coal called Coking or Metallurgical Coal which is shipped to key markets in Asia and all over the world to be used in the steel making process. Coking Coal is the only viable way at the moment to make steel which forms the framework of our life. 100% of Kestrel product is shipped from Gladstone Port in Queensland to ...

Read More
Study on Water Enrichment Prediction of Coal Roof ...

Sandstone roof water is the direct water-filling resource of coal mining, which has a great effect on the mine production. However, because of the unequal enrichment of Sandstone roof water, it is difficult to prevent and treat sandstone roof water. In order to study the water enrichment of coal roof sandstone, take 8# coal seam of ZhangBei coal mine as an example.

Read More
Piezoelectric effect and ignition properties of coal mine ...

In the process of roof sandstone rupture, instantaneous discharge formed owing to the piezoelectric effect, which could break through the air. Considering the Babao coal mine gas explosion accident, the high quartz content of the roof rock reached a certain compressive strength and experienced simultaneous stress mutation, exhibiting ...

Read More
(PDF) Directional hydraulic fracturing technology for ...

explore the characteristics of a coal mine roof sandstone. The triaxial compression curve is. shown in Figure 4. The uniaxial compressive strength was 131.7 MPa, the elastic modulus.

Read More
Coal Mine Geology In The U.S. Coal Fields: A State-Of

2012-8-30  details went unnoticed until the mine hit a sandstone channel, fault, or poor roof conditions which necessitated the operator to aimlessly turn headings left and right without success until the area had to be abandoned. Other mine operators were made aware of the benefits of underground mapping and geologic forecasting techniques

Read More
Mine Safety and Health Administration (MSHA) - Coal

2019-9-5  The immediate roof in the mine varies from shale, up to 25 feet thick, to sandstone. The immediate roof in the No. 4 section, the area of the accident, was sandstone. The sandstone unit above the Coalburg seam has a published Coal Mine Roof Rating (CMRR) of 96, indicating a very competent immediate roof. The mine floor consists of shale.

Read More
Analysis of Roof Failure at the Intersections on a Coal Mining

The objective of this paper is to understand the behavior of the roof and the cause of roof failure of a coal mining. Eleven roof falls occurred in the mine section in sequence. All the roof falls were surveyed, and the geological features were determined which include rock type, mechanical properties, and thickness. The immediate roof thickness was interpolated to determine the cause of the ...

Read More
Longwall Shield Recovery Using Mobile Roof Supports

2012-8-30  Mine, this shale unit can either be laminated, sandy, or nonexistent (replaced by a sandstone scour). These fluctuations explain the range in Coal Mine Roof Rating values from 44 to 71 (Molinda and Mark, 1994). These values indicate that the immediate roof rock is of moderate strength to strong.

Read More
The Characteristics of Roof Breaking and the Law of

2020-7-31  In view of the characteristics of large overburden movement space, strong mining disturbance and difficult to determine the initial pressure step distance of the roof in fully mechanized top-coal caving face with large mining height, the working face 101 of a coal mine is taken as the engineering background, through theoretical analysis, numerical simulation and field measurement methods are ...

Read More
Causes of Falls of Roof - Council for Scientific and ...

2021-9-11  In general, roof falls occurred in areas where the roof rock was found to be less competent in terms of rock mass rating systems. It was concluded that the Coal Mine Roof Rating (CMRR) system developed by NIOSH in the USA held promise for application in South Africa and should be

Read More
Our Coal and Our Clients – Kestrel Coal

Kestrel produces high energy coal called Coking or Metallurgical Coal which is shipped to key markets in Asia and all over the world to be used in the steel making process. Coking Coal is the only viable way at the moment to make steel which forms the framework of our life. 100% of Kestrel product is shipped from Gladstone Port in Queensland to ...

Read More