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Fundamental principles of an effective reinforcing roof ...

using anything other than roof bolts or chocks to control the mine roof. ex. lumber, safety jacks, etc. conventional support system: a long steel rod inserted in the mine roof to help hold its place: roof bolt: a type of roof bolt with an expandable shell on the end that when tightened expands and grips into the roof holding the bolt and roof ...

Coal Mining

Room and pillar mining involves cutting a system of rooms within the coal seem. Pillars are left in order to support the roof of the cut into coal seem. In a secondary mining method, called retreat mining, coal is systematically collected from the pillars, allowing the mine to close in behind them 2. This type of mining can be extremely dangerous.

Coal Mine Roof Rating (CMRR): A practical rock mass ...

Skin failures of roof and rib in underground coal mines continue to be a significant safety hazard for mine workers. Skin failures do not usually involve failure of the support systems, but result from rock or coal spalling from between the support elements. For instance, in 1997 more than 800 miners were injured by roof

Roof Support Systems

May 01, 2018· The coal mine roof rating (CMRR) is a measure of roof quality or structure competency for bedded roof types typically of underground coal mines. The CMRR has been used widely in the US, South Africa, Canada and Australia. In order to investigate the application of the CMRR system in Chinese coal mines, two coal mines in China located in ...

roof supports Archives

transports the coal to a conveyor system in the gate-road and the roof support system. The armored face conveyer has twin steel chains, which are sprocket driven by 800 – 1500 kW motors

Improvement of Power Quality in Underground Coal Mines ...

Sep 22, 2015· Intrinsic Roof Support – An empirically based software package, Analysis of Roof Bolt Systems (ARBS), has been developed to assist in design of roof bolt systems in coal mines. Surface Control – NIOSH Mining publications have documented the advantages of using roof screen or mesh to prevent ground fall injuries.

Coal Mining | JENNMAR

Coal has been mined at the Pinnacle site (formerly U.S. Steel #50) since 1969; since 1977, scores of panels have been mined using roof-fall exploitation with plows and roof supports. Faces are extracted using the retreat mining system. Initially, four parallel entries were prepared on each side of the face, resulting in very high heading costs.

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

Roof stitching was tried at a number of coal mines as well as in the metal mines at Balaghat and Seetharama mica mine. This method of support was found to be not only effective but also the cheapest. At Ballarpur mines a fault zone, over 60 m length, was successfully supported with the ropes.


Underground Applications: Mining Roof and Wall Support. Tensar ® Mining Systems address underground mine and tunnel applications including: . Rib Control – White and reflective, Tensar ® TX and BX Mining Grid products provide effective rib control for soft minerals, while Tensar ® UX3340 Roof Mats and Minex™ Rock Mesh address the most demanding hard rock and tunneling applications.


use of the latest, high-strength roof support systems in an effort to reduce hazards and prevent accidents. By recognizing and understanding these issues and conditions that continue to make coal mine roof and ribs so hazardous, we can begin to make progress in finding better ways to prevent injuries due to roof and rib falls.


5.2 Coal Mine Roof Rating (CMRR) Molinda and Mark (1994) have developed the Coal Mine Roof Rating (CMRR) classification system to quantify descriptive geological information for use in coal mine design and roof support selection. This system results from years of geologic ground control research in longwall mines in the United States.

Prop Support in Mining | Strata Worldwide

The roof control specialists are well equipped with stratascopes, roof bolt pull-test equipment, computers, and other state of the art equipment used in evaluating mine roof. A roof control specialist will visit your mine, upon request, and evaluate the type of roof support system …

Chocks | Introduction | underground COAL

Dec 05, 2016· CMRI report, geo-mechanical classification of roof rocks vis-a- vis roof supports, sand project report March 1987,125 III. Singh A K, Sinha A, Rao D G and Paul A. Roof bolting as a system of support for mechanised depillaring in coal mine – a case study, Proc Geomechanics and Ground Control, Dhanbad, 2003; 36-44 IV.

Analysis of the current rib support practices and ...

Roof Ranger II. Dual-head workhorse for seam heights of 48" - 96" (1.2m - 2.4m). Offset booms drill near rib while allowing a wider operator exit way toward rear of machine. Rugged ATRS usually eliminates the need to set temporary posts and jacks. Designed to install a full row of support from one chassis position. More Info


Design of a Powered Support System in Enugu Coal Mine Akande, J.M. and Saliu M.A. ... Geological Conditions of the Roof and floor: Coal seams may have shale, sandstone or combination of both as their roof or floor. If the floor is weak, there is limitation to the kind of mining equipment to be used. For example, tyre mounted machines cannot be ...

Free Unfinished Flashcards about 80 hr mining class

The use of rockbolting as roof support is an essential element of high productivity mechanized coal mining. In South Africa, the USA and Australia, rockbolting has been used in coal mine room-and-pillar operations for many years, and the productivity of this mining system continues to increase with advances in equipment design and capacity.

Coal mine roadway support system handbook

The CAN will be a strong addition to Strata's line of roof support systems and with this agreement we will offer the most complete portfolio of roof support products on the market." Strata Worldwide has grown from a company focused on roof supports in underground coal operations, to service mines of all types, all sizes, all commodities and ...


YOUR SUPPORT for LIFE.. Strata Worldwide was founded on its line of engineered secondary roof supports for underground coal mining. Originally introduced in 1993, the Strata Propsetter® support system remains one of Strata's top selling support props through-out the world.

An Overview Of Standing Roof Support Practices And ...

Roof stitching was tried at a number of coal mines as well as in the metal mines at Balaghat and Seetharama mica mine. This method of support was found to be not only effective but also the cheapest. At Ballarpur mines a fault zone, over 60 m length, was successfully supported with the ropes.

Timber Support in Underground Mining

Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically 0.6–1.0 m (2 ft 0 in–3 ft 3 in) thick). The longwall panel (the block of coal that is being mined) is typically 3–4 km (1.9–2.5 mi) long and 250–400 m (820–1,310 ft) wide.