|
Coal Mine Bump
A coal mine bump (a bump, a mine bump, a mountain bump, or a rock burst) is a seismic jolt occurring within an underground mine due to the explosive collapse of one or more support pillars. In room and pillar mining, tunnels are advanced in a rectangular pattern resembling city streets (tunnels), leaving behind blocks (pillars) of coal. To a miner, a partially completed tunnel resembles a room dug into the coal seam. As mining proceeds, the weight of rock overburden previously supported by coal mined from rooms is redistributed to pillars. If that weight exceeds the strength of a pillar, the pillar can fail by crushing or exploding. An explosive failure is called a “bump.”{{cite news , first=Seth , last=Bornstein, first2= Jennifer , last2=Talhelm , title=Stress Causes Killer Mine Bumps , date=2007-08-17 , publisher=Associated Press , URL =http://usatoday30.usatoday.com/news/topstories/2007-08-17-2823715890_x.htm?csp=34 , work =USA Today In the eastern United States' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Burst
A rock burst is a spontaneous, violent failure of rock that can occur in high-stress mines. Although mines may experience many mining-related seismic events, only the tremors associated with damage to accessible mine workings are classified as rock bursts. The opening of mine workings relieves neighboring rocks of tremendous pressure, which can literally cause the rock to explode, or trigger abrupt movement on nearby geological structures. Rock bursts are a serious hazard; in South Africa, they kill roughly 20 miners each year. Details Rock bursts result from brittle fracturing of rock, causing it to collapse rapidly with violent spalling of rock that is approximately 100 to 200 tonnes, or more. This release of energy reduces the potential energy of the rock around the excavation. Another explanation is that the changes brought about by the mine's redistribution of stress trigger latent seismic events, deriving from the strain energy produced by its geological aspects. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismic
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. It also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, glacial, fluvial, oceanic, atmospheric, and artificial processes such as explosions. A related field that uses geology to infer information regarding past earthquakes is paleoseismology. A recording of Earth motion as a function of time is called a seismogram. A seismologist is a scientist who does research in seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletus (c. 585 BCE), Anaximenes of Miletus (c. 550 BCE), Aristotle (c. 340 BCE), and Zhan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Room And Pillar
Room and pillar or pillar and stall is a variant of breast stoping. It is a mining system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. To do this, "rooms" of ore are dug out while "pillars" of untouched material are left to support the roof overburden. Calculating the size, shape, and position of pillars is a complicated procedure, and is an area of active research. The technique is usually used for relatively flat-lying deposits, such as those that follow a particular stratum. Room and pillar mining can be advantageous because it reduces the risk of surface subsidence compared to other underground mining techniques. It is also advantageous because it can be mechanized, and is relatively simple. However, because significant portions of ore may have to be left behind, recovery and profits can be low. Room and pillar mining was one of the earliest methods used, although with significantly more man-power. The room ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overburden
In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally finely milled ore. Overburden is removed during surface mining, but is typically not contaminated with toxic components. Overburden may also be used to restore an exhausted mining site during reclamation. Interburden is material that lies between two areas of economic interest, such as the material separating coal seams within strata.Peng, Syd S. (1986) ''Coal Mine Ground Control'' (2nd edition), Wiley, New York, page 303, Analogous uses Overburden is also used for all soil and ancillary material above the bedrock horizon in a given area. By analogy, overburden is also used to describe the soil and other material that lies ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratum
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as either '' bedding surfaces'' or ''bedding planes''.Salvador, A. ed., 1994. ''International stratigraphic guide: a guide to stratigraphic classification, terminology, and procedure. 2nd ed.'' Boulder, Colorado, The Geological Society of America, Inc., 215 pp. . Prior to the publication of the International Stratigraphic Guide, older publications have defined a stratum as either being either equivalent to a single bed or composed of a number of beds; as a layer greater than 1 cm in thickness and constituting a part of a bed; or a general term that includes both ''bed'' and ''lamina''.Neuendorf, K.K.E., Mehl, Jr., J.P., and Jackson, J.A. , eds., 2005. ''Glossary of Geology'' 5th ed. Alexandria, Virginia, American Geological Institute. 779 pp. . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retreat Mining
Retreat mining is the removal of pillars in the underground mining technique known as room and pillar mining. In the first phase of room and pillar mining, tunnels are advanced into the coal or ore body in a rectangular pattern resembling city streets. Pillars are left between tunnels to support the weight of the overburden. The first phase is known as "mining on the advance," from the entrance toward the further reaches of the reserve. In the second phase, once advance mining has been completed, pillars are removed "on the retreat." Removing or "pulling" pillars begins far from the entrance and proceeds toward the entrance. As the pillars are removed, the mine collapses because nothing remains to support the roof and overburden. Removing pillars causes stresses within the mine to shift and must be planned and executed carefully to reduce danger to miners and control the amount of stress exerted on remaining pillars and the mine floor. Tunnels only make up about 15% of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springhill Mining Disaster
Springhill mining disaster may refer to any of three deadly Canadian mining disasters that occurred in 1891, 1956, and 1958 in different mines within the Springhill coalfield, near the town of Springhill in Cumberland County, Nova Scotia. In the 1891 accident, 125 died; in 1956, 39 were killed; and in 1958, there were 75 miners killed. The mines in the Springhill coalfield were established in the 19th century, and by the early 1880s were being worked by the Cumberland Coal & Railway Company Ltd. and the Springhill & Parrsboro Coal & Railway Company Ltd. These entities merged in 1884 to form the Cumberland Railway & Coal Company Ltd., which its investors sold in 1910 to the industrial conglomerate Dominion Coal Company Ltd. (DOMCO). Following the third disaster in 1958, the operator Dominion Steel & Coal Corporation Ltd. (DOSCO), then a subsidiary of the A.V. Roe Canada Company Ltd., shut its mining operations in Springhill, and they were never reopened. the mine properti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springhill, Nova Scotia
Springhill is a community located in central Cumberland County, Nova Scotia, Canada. The community was founded as "Springhill Mines." Coal mining led to economic growth, with its incorporation as a town in 1889. The mines in the Springhill coalfield were established in the 19th century, and by the early 1880s were being worked by the Cumberland Coal & Railway Company Ltd. and the Springhill & Parrsboro Coal & Railway Company Ltd. These entities merged in 1884 to form the Cumberland Railway & Coal Company Ltd., which its investors sold in 1910 to the industrial conglomerate Dominion Coal Company Ltd. (DOMCO). All coal mining had ceased in the area by the early 1970s. The community is famous for both the Springhill Mining Disaster and being the childhood home of international recording star Anne Murray, who is honoured by the Anne Murray Centre, a popular tourist attraction. As of 2015 the mine properties, among the deepest in the world, with the No. 2 mine reaching 14,300 fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total area. Its southern and western border with the United States, stretching , is the world's longest binational land border. Canada's capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. Indigenous peoples have continuously inhabited what is now Canada for thousands of years. Beginning in the 16th century, British and French expeditions explored and later settled along the Atlantic coast. As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crandall Canyon Mine
The Crandall Canyon Mine, formerly Genwal Mine, was an underground bituminous coal mine in northwestern Emery County, Utah. The mine made headline news when six miners were trapped by a collapse in August 2007. Ten days later, three rescue workers were killed by a subsequent collapse. The six miners were later declared dead and their bodies were never recovered. Location and geography The Crandall Canyon Mine is located at (39.460000°, -111.167639°) with its entrance at an elevation of 7,835 feet (2,388m). The mine is located in Emery County, Utah, in the Wasatch plateau coal field. The mine is located about 140 miles (225 km) south of Salt Lake City, 34 miles (55 km) southeast of Fairview, and about 15 miles (24 km) west north-west of Huntington. The mine is located in Crandall Canyon about 1.25 miles (2 km) west of its junction with the main highway road, State Route 31, which runs through Huntington Canyon. The Manti-La Sal National Forest surrounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert E
The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honour, praise, renown" and ''berht'' "bright, light, shining"). It is the second most frequently used given name of ancient Germanic origin. It is also in use as a surname. Another commonly used form of the name is Rupert. After becoming widely used in Continental Europe it entered England in its Old French form ''Robert'', where an Old English cognate form (''Hrēodbēorht'', ''Hrodberht'', ''Hrēodbēorð'', ''Hrœdbœrð'', ''Hrœdberð'', ''Hrōðberχtŕ'') had existed before the Norman Conquest. The feminine version is Roberta. The Italian, Portuguese, and Spanish form is Roberto. Robert is also a common name in many Germanic languages, including English, German, Dutch, Norwegian, Swedish, Scots, Danish, and Icelandic. It can be use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston Herald
The ''Boston Herald'' is an American daily newspaper whose primary market is Boston, Massachusetts, and its surrounding area. It was founded in 1846 and is one of the oldest daily newspapers in the United States. It has been awarded eight Pulitzer Prizes in its history, including four for editorial writing and three for photography before it was converted to tabloid format in 1981. The ''Herald'' was named one of the "10 Newspapers That 'Do It Right' in 2012 by '' Editor & Publisher''. In December 2017, the ''Herald'' filed for bankruptcy. On February 14, 2018, Digital First Media successfully bid $11.9 million to purchase the company in a bankruptcy auction; the acquisition was completed on March 19, 2018. As of August 2018, the paper had approximately 110 total employees, compared to about 225 before the sale. History The ''Herald'' history can be traced back through two lineages, the '' Daily Advertiser'' and the old ''Boston Herald'', and two media moguls, William Randolph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
