Sandstone Coal Mine Roof

Mine Waste Characterisation701 1 Introduction Adani Mining Pty Ltd Adani is proposing to develop the Carmichael Coal Mine and Rail Project the ProjectA portion of the carbonaceous mudstone carbonaceous siltstone claystone sandstone and siltstone roof and floor and coal materials could be expected to be potentially acid

The Coal Mine Roof Rating CMRR was developed 10 years ago to fill the gap between geologic characterization and engineering design It combines many years of geologic studies in underground coal mines with worldwide experience with rock mass classification systems Like other classification systems the CMRR begins with

Oct 19 2019 Sandstone is the main medium of the coal seam roof in the Jushan Mine and has poor physical and mechanical properties To study the creep behavior of sandstone triaxial creep tests and simulations are conducted under different confining pressures and degrees of damage

Dec 05 2012 The Sewickley is a rich coal seam that lies 70130 ft 21343962 m above the Pittsburgh coal seam in Southwestern Pennsylvania From a ground control perspective the seam has proven very difficult to mine because of the complex and varying ground control issues that are present

sandstone and limestone The Coal Mine Roof Rating CMRR ranges from 3083 and averages 44 The depth of cover ranges from 25900 ft and averages 325 ft Coal mine roof that falls before the installation of roof bolts can be hazardous From 19952008 24 miners were killed while travelling beneath unsupported roof MSHA 19952008

Jan 30 2016 Usually composed of interbedded siltstone fossiliferous shale and thin layers of sandstone Coal Mine Roof Rating CMRR values typically range between 40 and 60 with typical UCS values of 5080 MPa Maleki et al 2006 Stewart et al 2006 The immediate floor usually contains a considerable thickness of coal

The mine experienced a coaldust explosion on January 4 1972 in which three men were injured On June 19 1972 methane was ignited at a working face when the cutting head of a continuous miner contacted sandstone roof None of the face employees were injured by the ignition

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

Sandstone channels are constant hazards to coal mining operations the presence of a channel over a seam can result in thinning of the seam changes in stress orientations variation in stress intensity abrasive cutting roof hangup faulting jointing loading of the face and even wind blasts Prediction of the trend of a channel is usually difficult as channels tend to meander and follow

Geologic Hazards and Roof Stability in Coal Mines By Gregory M Molinda US DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Pittsburgh Research Laboratory Pittsburgh PA

Jan 17 2021 Mining that uses continuousmining machines to cut into coal seams leaves behind pillars or columns of coal to help support the mine roof and control the flow of air

This thesis presents a logical design methodology for coal mine extraction optimization under massive sandstone roof as developed though a case study analysis of the Quinsam Coal 4 South mine a shallow underground room and pillar mine with a massive sandstone roof This research is intended to guide Quinsam Coal and other coal mines globally in efforts to develop or optimize coal extraction

A coal mine is a mediumsized mine with an annual output of 900000 tons The mining depth of the main coal seam reaches more than 500 m with shaft development adopted The main mining coal seam is located at 1210 level and is a thick coal seam with a thickness of 315680 m and an average thickness of 420 m

In underground coal mines roof falls are a major contributor to injuries and fatalities Studies have related the occurrence of roof fall to weak immediate roof high horizontal stress entry orientation etc An oftenneglected factor in studies on this topic has been the influence of timedependent behavior of the roof rock on roof falls

Coal Operators Conference Faculty of Engineering and Information Sciences 2003 Analysis of unsupported roof spans highwall mining at Moura coal mine John Hoelle Anglo Coal Research Online is the open access institutional repository for the University of Wollongong For further information contact the UOW Library researchpubsuoweduau

Anthracite coal with a volatile ratio equal to 012 or less Anticlinal axis the ridge of an anticline Anticline an upward sold or arch of rock strata Aquifer a water bearing bed of porous rock often sandstone Arching fracture processes around a mine opening leading to stabilization by

Sep 23 2001 No 5 Mine had a higher injury rate than threequarters of US underground coal mines during the last decade making it one of the most hazardous in the country Federal officials cited a

Roof fall A coal mine cavein especially in permanent areas such as entries Sandstone A sedimentary rock consisting of quartz sand united by some cementing material such as iron oxide or calcium carbonate Scaling Removal of loose rock from the roof or walls This work is dangerous and a long bar called a scaling baris often used

Additional mining obstacles that can affect all coal beds and roof strata are 1 tectonic faulting which is prevalent in western Kentucky 2 fractures related to low cover and past mining and 3 fractures related to the regional tectonic stress field Figure 1 Major coal beds and stratigraphy of the Western Kentucky Coal Field From Greb

The top of the coal was eroded but 4 to 5 feet of coal remained These channels of Anvil Rock Sandstone channels are evident in the mining patterns shown on the accompanying map Most channels were 200 to 400 feet wide with wider flanking zones of wet conditions andor unstable roof

Seam parting is common within the coal seams on the properties with intraseam parting material increasing drastically in some areas Roof strata are typically shale or sandy shale with zones of sandstone roof being common Floor strata are typically sandstone shale sandy shale fireclay or in the case of the Upper Kittanning limestone

Solid backfill coal mining technology has been widely applied in coal seams that are at risk of hard roof Using actual measured strainstress curves of the backfill body and the similarity

The immediate mine roof consists of gray shale to siltstone sandstone or interbedded shales and sandstone known as stackrock Employment is provided for 194 underground and 18 surface employees The mine is operated three shifts per day five days per week producing 21000 tons of raw coal per day from two continuous mining machine units