Overview of mining and its impacts environmental law alliance. To name a mineral prospect an ore body requires more information than needed to establish metal grades. Longwall mining method longwall method of working consists in laying out long faces 60200 m long from which all coal in working section of the coal seam is removed by a series of operations, maintaining a continuous line of advance in one direction and leaving behind the void called goaf. Longwall mining a to z coal has been mined underground in the united states for more than 200 years. In this method of mining, an unmanned continuous miner is driven underground and operated in front of the highwall. Longwall mining is a met hod in whic h all parts must operate as a n i ntegrated system. Choice of method welcome to the narrowvein mining project.
Longwall mining machines consist of multiple coal shearers mounted on a series of selfadvancing hydraulic ceiling supports. Sufficient knowledge of the mineral deposit, mining. For most of that time the primary method of extraction was roomandpillar mining, which continues to be a feasible and profitable mining method. Highwall mining is a proven primary method for mining coal from outcropping horizontal seams. Another milestone was yet another invention by westfalia. Determination of longwall mininginduced stress using the. Hr no pillar remnants costs lower especially support costs personnel concentrated in one place training easier method to learn roof can be weak but might affect gateroads product coal is easy to wash, less fines ventilation is more concentrated good air upwind of shearer. Us mining industry energy bandwidth study department of energy. Overall, six broad classes of data mining algorithms are covered.
Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. Underground coal production by state and mining method, 2018 thousand short tons coalproducing state and region1 continuous conventional and other2 longwall total alabama 2,378 11 9,811 12,199 colorado 1,647 8,767 10,414 illinois 20,209 974 24,890 46,072 indiana 17,356 17,356. Chain pillar, longwall mining, numerical methods, pillar design, pillar optimization 1. The highwall mining method originated in the usa in the 1940s. Following the initial consultations, the pilot process aimed to recruit mining. The other principal method of modern mining, longwall mining, had been introduced as early as the 17th century and had found general use by the 19th century, but it had long been less productive than roomandpillar mining. Introduction to longwall mining and subsidence ver2. Although widely used in other countries, longwall mining. This technology steplike most inventions in plowingcame from caterpillar predecessor westfalia luenen. Longwall mining is a highly productive underground coal mining technique. In this method, the face is formed perpendicular to the seam strike and implemented in the form of slices 7. Plotmaker mining methods blackout day presentation 5 th december 2008 venkat m. This method of mining was developed in the late 1960s to take advantage of the then recent development of suitable hydraulic longwall supports, coupled with the productivity and low capital cost of continuous miners and shuttle cars.
It is a largescale mining method suitable for large ore bodies with a steep dip and a rock mass with a host rock in the hanging wall will fracture under controlled conditions. Both methods are well suited to extracting the relatively flat coalbeds or coal seams typical. This video provides a basic description of the longwall mining method for extracting coal underground. The longwall panel the block of coal that is being mined is typically 34 km 1. Usually, the development is done two years in advance of the production schedule. It set of longwall mining equipment consists of a coal shear er mounted on convey or operating. At present the bulk of development is related to surface mines, the result of simpler communication setups and availability of gps global positioning systems. Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice typically 0. Longwall general layout top gate face dip direction bottom gate longwall mining method includes drivage of two long roadways in coal and joining them at the end by a perpendicular drivage forming a face.
Teleoperation of a highwall mining system by august j. Shortwall mining is a method of mining in which a continuous miner cuts and loads from the short end of a rectangular pillar of coal while hydraulically powered selfadvancing roof supports provide protective cover. Cat plows offer worldleading features that other manufacturers cannot and a cost of ownership that far outstrips the shearer when mining thin and medium seams. Production mining is further broken down into two methods, long hole and short hole. Longwall and caving methods are distinguished from other mining methods by the fact that the nearfield rock undergoes large displacements so that mined voids become selffilling.
The mining method mostly used is a transverse primary and secondary longhole method. Punch multislice longwall mining system for thick coal. A typical section through a coal face is shown in fig. Longwall mining overview introduction underground coal. Underground hard rock mining refers to various underground mining techniques used to. This mining method was used in mines in counties over 119 figure 161. Shortwall mining pdf other methods depending on seam. Both methods are well suited to extracting the relatively flat coalbeds or coal seams typical of the united states.
Shortwall stoping versus sublevel longwall cavingretreat. The highwall mining machine stands on the pit floor or on a bench, directly in front of the exposed seam and makes. Threedimensional numerical modelling of longwall mining. Leigh or of united states department of the interior bureau of mines. While opencast operations are now fully mechanized employing large capacity earth moving equipment, introduction of machinery in underground workings has been gradual. Therefore, when narrower areas are encountered in these sectors, the mining method generally used to recover these stopes is the longhole retreat method. The pm4 was the worlds first and only mineworthy and rugged control system, and it was introduced in 1993. Studies estimate that 156 billion tons of coal, representing 68 pct of the minable reserves in the united states, is subject to multipleseam mining. Threedimensional numerical modelling of longwall mining from final highwall at mae moh lignite mine, thailand s. I am pleased to present the department of homeland securitys dhs 20 data mining report to congress. The aim of the method was to recover coal from a surface mine that has reached its economic limit. Advances in longwall mining method have made this system more economically attractive because of its efficiency and production potential. Modern longwall mining operations have been optimized to the point where manual operation of the process limits the future development of. The glory hole method is best suited to mining on a hillside, and irregular deposits.
Longwall mining is used extensively worldwide and accounts for over 80% and 50% of underground coal production in australia and the usa respectively. Longwall mining is a highly mechaniz ed underground mining sys tem for mining coal. Introduction longwall is an underground mining method which has a high rate of production capacity and. In longwall mining, a panel of coal, typically around 150 to 300 metres wide, to 3500 metres long and 2 to 5 metres thick, is totally removed by longwall shearing machinery, which travels back and forth across the coalface. Final report effects of longwall mining pdf format. A long hole stoping system for mining narrow platinum reefs advantages of this mining method it allows for a low safety and health risk as well as improved working environment. Definition of longwall mining a high extraction method of mining along the face of a predefined block of coal, referred to as a panel, while allowing the immediate roof to collapse upon advancement panel configuration panels generally range in size from 500 to 1,000 feet in width and lengths exceeding two miles. This page was last edited on 15 january 2020, at 14. This is an accounting calculation, followed by the application of a.
National institute of technology rourkela certificate this is to certify that the thesis entitled, behavior of shield support in longwall mining submitted by mr. Final report effects of longwall mining on real property value and the tax base of greene and washington counties, pennsylvania table of contents adobe acrobat format. Historically, roomandpillar mining has dominated coal production, and this mining method has been the focus of most multipleseam research. A long hole stoping system for mining narrow platinum reefs. It includes an explanation of the different productskey components of a longwall mining. Physical work is reduced and it is easier to motivate the workforce. In the shortwall mining method, the layout is similar to the longwall method except that the block of coal is not more than 100 metres wide. Longwall mining machines are about 800 feet 240 meters in width and 5 to 10 feet. The essential geomechanical features of longwall and caving methods of mining were outlined in chapter 12. Open pit mines are used to exploit low grade, shallow ore bodies.
Sublevel caving mining method newtrax technologies inc. Eia for the exploratory phase of a mining project because. The object of this article is to present all the aspects of underground mining. Discuss whether or not each of the following activities is a data mining task.
Thus, knowledge of the mininginduced stress is very important to enable accurate design of gate supports and pillar. The federal agency data mining reporting act of 2007, 42 u. Mining methods the phenomenal rise in coal production, nearly sixfold in the past three decades, necessitated rapid but judicious mechanization of mining methods. A brief comparison of longwall methods used at mining of. Content is available under creative commons attributionnoncommercialsharealike. We suggest you first download these files to your computer. Current longwall mining method applied in the mine the current method used in the abovementioned mines is a sublevel longwall cavingretreat method. Furthermore, the slices are as much as three metres thick and are taken by a continuous miner. Longwall mining and roomandpillar mining are the two basic methods of mining coal underground, with roomandpillar being the traditional method in the united states.
Longwall and shortwall mining methods and equipment. Team lead minex, india slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Although there are a number of other algorithms and many variations of the techniques described, one of the algorithms from this group of six is almost always used in real world deployments of data mining systems. Seven longwalls are currently active in the alabama coalfields. Introduction of innovative technologies to mining is a precondition to development of more efficient, computerized, total mining systems. Sublevel caving is one of many different methods for underground hard rock mining. Been determined that the shortwall mining method will out perform the longwall. Longwall mining panelandpillar and roomandpillar bordandpillar mining are the two. In the method of secondary extraction known as longwall mining a relatively long mining face typically in the range 100 to 300m but may be longer is created by driving a roadway at right angles between two roadways that form the sides of the longwall block, with one rib of this new roadway forming the longwall face. Group 7 the joy shearer, introduced in 1976, was the first multimotor shearer and this design concept became the global standard for all longwall shearers. Implementation of paste backfill mining technology in. Plow technology history and the state of the industry. Final report effects of longwall mining on real property.
1556 1009 500 773 10 1434 955 165 1252 1134 1502 706 751 137 1224 502 1150 1062 119 310 1487 775 1210 1320 1134 1331 98 1468 831 277 816 312 100 540 826 333 93