User:Widdes
Coals are little black lumps that are the means of producing more than half of the United States of America’s electricity. Coal is an important component of Methanol which resides in binding resin, plywood, and acetic acid, plastic bottles; just to name a few[1]. Coal has been used for a long time and in many ways. Fueled by the Industrial Revolution, coal mining began in Pennsylvania in the mid-1700. The initial reason was to support the Colonial Iron Industry and then Andrew Carnegie's steel mills in the 1800's and then the electric power plants which are currently used . Throughout the years coal has fueled many different things in order to keep America going. Coal is reliable and can be used in a variety of ways. Coals are sought after around the world by the use of many different techniques.
Once the coal is removed, usually 75 percent of the section, the roof is allowed to collapse in a safe manner after the miners have cleared out[2]
Room & Pillar Mining
Room & Pillar mining consists of coal deposits that are mined by cutting a network of rooms into the coal seam. Pillars of coal are left behind in order to keep up the roof. The Pillars can make up to forty percent of the total coal in the seam. Though, this can be abstracted at a later stage[3]
New braces called Atlas Cribs contain a mix of hardwoods and a main lateral element that make these braces stronger than other braces used in the past. The new cribbing system takes up 41 percent less area than existing ones and may be up to 50 percent more efficient in terms of airflow.[4]
Large opencast mines can cover an area of many square kilometers and use very large pieces of equipment. This equipment can include the following: Draglines which operate by removing the overburden, power shovels, large trucks in which transport overburden and coal, bucket wheel excavators, and conveyors.
Explosives are first use in order to break through the surface of the mining area; it is then removed by draglines or by shovel and truck. Once the coal seam is exposed, it is drilled, fractured and thoroughly mined in strips. The coal is then loaded on to large trucks or conveyors for transport to either the coal preparation plant or direct to where it will be used[5].
- ^ Dawn, Anderson and Brehmer, Erica "Coal Mining." The Environmental Literacy Council.. 26 June 2008. 9 Mar. 2009 <http://www.enviroliteracy.org/article.php/1122.html>.
- ^ "Coal Mining." World Coal. World Coal Institute. 10 Mar. 2009 <http://www.worldcoal.org/pages/content/index.asp?PageID=92>.
- ^ "Coal Mining." World Coal. World Coal Institute. 10 Mar. 2009 <http://www.worldcoal.org/pages/content/index.asp?PageID=92>.
- ^ Southern Illinois University Carbondale. "New Technology Will Enhance Coal Mine Safety." ScienceDaily 22 July 2008. 10 March 2009 <http://www.sciencedaily.com/releases/2008/07/080717221913.htm>.
- ^ "Coal Mining." World Coal. World Coal Institute. 10 Mar. 2009 <http://www.worldcoal.org/pages/content/index.asp?PageID=92>.
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