Coal mining method pdf

Advances in longwall mining method have made this system more economically attractive because of its efficiency and production potential. Recoverable coal reserves at producing underground coal mines by state and mining method available formats. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. The downside to this however was that valuable coal had to be left behind. As thick rock partings delay the efficient mining of coal seams and constrain the sustainable development of coal mines, an innovative. Innovative extraction method for a coal seam with a thick. Surface and underground coal mining are broad activities that incorporate numerous variations in equipment and methods, and the choice of which method to use in extracting a coal seam depends on many technological, economic. The details of all publications are in the researchgate in full text pdf forms. Depending on the mining method, a working section can have one or more working faces. It is defined as a concentration of minerals that can be exploited and turned into a saleable product to generate a financially acceptable profit under existing economic conditions.

A coal mining method that accounts f or less than 1% of deep coal production, shortwall involves the use of a continuous mining machine with mov eable roof supports, similar to longwall. Coal is usuallyrecovered from underground mines in either of two methods. Longwall mining and roomandpillar mining are the two basic methods of mining coal underground, with roomandpillar being the traditional method in the united states. Dec 05, 2008 plotmaker mining methods blackout day presentation 5 th december 2008 venkat m. Underground mining is usually by the roomandpillar mining or longwall mining method. Coal is valued for its energy content and since the 1880s, has been widely used to generate electricity. An underground mine consists of the portals entrance and exits to the mines, mains, submains, panels, and working faces. Even in mines where the longwall method is the principal extraction method, the development of the mine and the longwall panels is accomplished by roomandpillar continuous mining. In this selection some of the parameters such as geological and geotechnical properties, economic parameters and geographical factors are involved. Underground mining methods and applications production headframe hans hamrin 1.

Coal mining methods can be broadly divided into two types viz. The other underground mining method commonly used in the united states is the longwall mining method. This method of mining ensures fast and precise extraction of this precious mineral resource. It is not an exact science and in the choice of a method each varying factor has a certain weight, which, in many cases, experience alone can determine. The various methods of mining a coal seam can be classified under two headings, surface mining and underground mining. In both methods, the coal seam is developed by driving entries and crosscuts to create blocks or pillars of coal by the roomandpillar method. Longwall mining overview introduction underground coal.

While opencast operations are now fully mechanized employing large capacity earth moving equipment, introduction of machinery in underground workings has been gradual. It is a very lowcost, highproductivity method of mining. Apr 03, 2017 the first published, reference to the mining of coal in india dates back to the year 1774 in the raniganj coal field. The mines are now operating at significantly higher annual tonnages, growing deeper, more complex and. A typical section through a coal face is shown in fig. Pdf coal mining methods underground mining longwall. Room and pillar mining was one of the earliest methods used, although with significantly more manpower. Mining method selection by multiple criteria decision making tools by m. Classification of underground mining methods mineral production in which all extracting operations are conducted beneath the ground. Coal mining is the process of extracting coal from the ground. In the united kingdom and south africa, a coal mine and its. Coal mining and production industry description and practices coal is one of the worlds most plentiful energy resources, and its use is likely to quadruple by the year 2020. 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. The company established a modern, coal handling and processing plant chpp which has facilitated production of washed coal of different specifications with consistent quality and eliminated pollution of nearby streams.

Early mining methods history of coal mining housefuel. The phenomenal rise in coal production, nearly sixfold in the past three decades, necessitated rapid but judicious mechanization of mining methods. 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. Energy information administration annual coal report 2018 table 22. Team lead minex, india slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Longwall top coal caving introduction underground coal. Auger mining is a relatively low cost method of coal mining and is. Bauer, illinois state geological survey 72015 introduction. Inclination of coal seam is the main parameter for determining the type of wall face of mining stopes. 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. The panels are the working sections of the production operation.

In alaska underground mining was the primary form of coal mining used until about the late 1930s early 1940s i was unable to find an exact date. Surface mining methods and underground mining method. Mining method selection by multiple criteria decision making. This appendix presents additional details on the individual processes that are involved in extraction of coal from surface and underground mines, and the. 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. The indian coal industry is the worlds third largest in terms of production and fourth largest in terms of. What follows are the typical phases of a proposed mining project. Underground mining methods vary according to the site. Pdf currently almost 65 % of the coal in australia is being produced by opencast mining methods.

The current methods for phc analysis are more advanced and can adequately predict. Longwall top coal caving ltcc is a special type of longwall mining applicable to very thick seams greater than 4. The method of surface mining was first recorded being used in the healy river area where it is still in use by the usibelli coal mine. Pdf minerals and mineral products are the backbone of most industries. A continuous miner with single or multiple augerscutting heads is operated underground and controlled remotely by crew located outside. Large rectangular blocks of coal are defined during the development stage of the mine and are then extracted in a single continuous operation. The choice of mining method largely depends on the geology of the coal deposit. Chain conveyors then move the loosened coal to an underground mine. Longwall mining was a method where workers would mine at the coal face and as the mining face moved further along the seam, timber supports would be put in place prevent caveins. Mining method selection by multiple criteria decision. Both methods are well suited to extracting the relatively flat coalbeds or coal seams typical of the united states. Ataei synopsis mining method selection is the first and most important problem in mine design.

In longwall mining, a rotating drum is trammed mechanically across the face of coal, and a hydraulic system supports the roof of the mine while it advances through the coal. The mining method selected for exploitation is determined mainly by the characteristics of the coal deposit and the limits imposed by safety, technology, environmental concerns, and economics. In any discussion of methods of underground mining comparison, one is repeatedly confronted with the difficulty of dealing with so many variable conditions. Highwall mining is a coal mining method for recovery of outcropped coal by mechanical excavation without removal of overburden. Open cut mining methods strip mining largescale open cut coal mining operations commenced in australia in mid 1960s and since then there has been significan t developments in this method of mining. Each phase of mining is associated with different sets of environmental impacts. Recognised standard 12 place change mining operations in underground coal mines, department of natural resources and mines, 2015 1. Historically, roomandpillar mining has dominated coal production, and this mining method has been the focus of most multipleseam research.

Introduction to longwall mining and subsidence ver2. Surface coal mining productivity by state and mining method, 2018 short tons produced per employee hour coalproducing state and region1 contour strip area open pit mountaintop mining other2 total alabama 1. Underground coal mining methods and engineering dust controls. Underground mining currently accounts for a bigger share of world coal production than opencast. T ypical example s of this type of mining are the larger tonna ge coal mining operations in mpumulanga. Coal occurs in a wide range of forms and qualities. Coal is an organic sediment consisting of a complex mixture of. Both methods are well suited to extracting the relatively flat coalbeds or coal seams typical of. Review of coal mining technologies currently used at federal mines although underground mining was, at one time, the principal mining method in parts of colorado, montana, wyoming, and north dakota, and continues to be so in utah, surface coal mining now predominates in most areas of the west. Underground coal mining productivity by state and mining method, 2018 short tons produced per employee hour coal producing state, region1 and mine type continuous conventional and other2 longwall total alabama 2. The room and pillar system is used in mining coal, gypsum, iron, and uranium ores, particularly when found as manto or blanket deposits, stone and aggregates, talc, soda ash and potash. In the past, separate machines were used for cutting, drilling, blasting, and loading the coal and the method was called conventional roomandpillar mining.