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Coal Dust
Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form of fugitive dust. Grinding coal to dust before combusting it improves the speed and efficiency of burning and makes the coal easier to handle. However, coal dust is hazardous to workers if it is suspended in air outside the controlled environment of grinding and combustion equipment. It poses the acute hazard of forming an explosive mixture in air and the chronic hazard of causing pulmonary illness in people who inhale excessive quantities of it. The distribution of the particle-size of coal dust is frequently measured in mesh. The British slang term for cheap fuel consisting of coal dust (slack) containing small lumps of coal (nuts) is nutty slack. Risks The Occupational Safety and Health Administration (OSHA) has set the legal limit (P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powder
A powder is a dry, bulk solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and ''granular'' are sometimes used to distinguish separate classes of material. In particular, ''powders'' refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing. ''Granulars'' refers to the coarser granular materials that do not tend to form clumps except when wet. Types Many manufactured goods come in powder form, such as flour, sugar, ground coffee, powdered milk, copy machine toner, gunpowder, cosmetic powders, and some pharmaceuticals. In nature, dust, fine sand and snow, volcanic ash, and the top layer of the lunar regolith are also examples. Because of their importance to industry, medicine and earth science, powders have been studied in great detail by chemical engineers, mechanical engi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spontaneous Combustion
Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by self-heating (increase in temperature due to exothermic internal reactions), followed by thermal runaway (self heating which rapidly accelerates to high temperatures) and finally, autoignition. Cause and ignition Spontaneous combustion can occur when a substance with a relatively low ignition temperature (hay, straw, peat, etc.) begins to release heat. This may occur in several ways, either by oxidation in the presence of moisture and air, or bacterial fermentation, which generates heat. The heat is unable to escape (hay, straw, peat, etc. are good thermal insulators), and the temperature of the material rises. The temperature of the material rises above its ignition point (even though much of the bacteria are destroyed by ignition temperatures). Combustion begins if sufficient oxidizer, such as oxygen, and fuel are present to maintain the reaction into thermal runaway. Affected materials ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Faraday
Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, diamagnetism and electrolysis. Although Faraday received little formal education, he was one of the most influential scientists in history. It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the concept of the electromagnetic field in physics. Faraday also established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.. the 1911 Encyclopædia Britannica. He similarly discovered the principles of electromagnetic induction, diamagnetism, and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firedamp
Firedamp is any flammable gas found in coal mines, typically coalbed methane. It is particularly found in areas where the coal is bituminous. The gas accumulates in pockets in the coal and adjacent strata and when they are penetrated the release can trigger explosions. Historically, if such a pocket was highly pressurized, it was termed a "bag of foulness". Name Damp is the collective name given to all gases (other than air) found in coal mines in Great Britain and North America. As well as firedamp, other damps include ''blackdamp'' (nonbreathable mixture of carbon dioxide, water vapour and other gases); whitedamp (carbon monoxide and other gases produced by combustion); poisonous, explosive ''stinkdamp'' (hydrogen sulfide), with its characteristic rotten-egg odour; and the insidiously lethal ''afterdamp'' (carbon monoxide and other gases) which are produced following explosions of firedamp or coal dust. Etymology Often hyphenated as fire-damp, this term for a flammabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benxihu Colliery
Benxihu (Honkeiko) Colliery (), located in Benxi, Liaoning, Republic of China (1912–1949), China, was first mined in 1905. Originally an iron and coal mining project under joint Japanese and Chinese control, the mine came under predominantly Japanese control. In the early 1930s, Japan invaded the northeast of China, and Liaoning province became part of the Japanese-controlled puppet state of Manchukuo. During the Second Sino-Japanese War, the Japanese forced Chinese labourers—some of whom had been captured from local military organizations—to work the colliery under very poor conditions. Food was scarce and workers did not have sufficient clothing. Working conditions were harsh, and diseases such as typhoid and cholera flourished due to poor sanitation and water supplies. Typically miners worked 12-hour shifts or longer. The Japanese controllers were known to beat workers with pick handles, and the perimeter of the mine was fenced and guarded. Many describe the conditions as s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luisenthal Mine
The Luisenthal Mine was a coal mine near Völklingen. The mine was known as the site of the largest mine accident in the history of the German Federal Republic, when 299 miners died on 7 February 1962. 1962 mine disaster On 7 February 1962 a methane explosion occurred after the opening of a methane-containing cavern in the Alsbach field. This triggered a larger coal dust explosion with devastating effects. 284 workers were killed, making this the greatest mining catastrophe in the history of the Saarland coal mining area. See also * Luisenthal Formation The Luisenthal Formation is a geologic formation in Germany. It preserves fossils dating back to the Carboniferous period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, en ... References {{Coord, 49, 15, 02, N, 6, 54, 18, E, region:DE-SL_type:landmark_source:dewiki, display=title 1962 in Germany Buildings and structures in Saarbrücken (distri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courrières Mine Disaster
The Courrières mine disaster, Europe's worst mining accident, caused the death of 1,099 miners in Northern France on 10 March 1906. This disaster was surpassed only by the Benxihu Colliery accident in China on 26 April 1942, which killed 1,549 miners. A coaldust explosion, the cause of which is not known with certainty, devastated a coal mine operated by the ''Compagnie des mines de houille de Courrières''. Victims lived nearby in the villages of Méricourt (404 people killed), Sallaumines (304 killed), Billy-Montigny (114 people killed), and Noyelles-sous-Lens (102 people killed). The mine was 2 km (1 mi) to the east of Lens, in the Pas-de-Calais département'' (about 220 km, or 140 miles, north of Paris). A large explosion was heard shortly after 06:30 on the morning of Saturday 10 March 1906. An elevator cage at Shaft 3 was thrown to the surface, damaging the pit-head; windows and roofs were blown out on the surface at Shaft 4; an elevator cage rai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Wales
South Wales ( cy, De Cymru) is a loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the historic counties of Glamorgan and Monmouthshire, south Wales extends westwards to include Carmarthenshire and Pembrokeshire. In the western extent, from Swansea westwards, local people would probably recognise that they lived in both south Wales and west Wales. The Brecon Beacons National Park covers about a third of south Wales, containing Pen y Fan, the highest British mountain south of Cadair Idris in Snowdonia. A point of some discussion is whether the first element of the name should be capitalised: 'south Wales' or 'South Wales'. As the name is a geographical expression rather than a specific area with well-defined borders, style guides such as those of the BBC and ''The Guardian'' use the form 'south Wales'. In a more authoritative style guide, the Welsh Government, in their international gateway website, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dust Explosion
A dust explosion is the rapid combustion of fine particles suspended in the air within an enclosed location. Dust explosions can occur where any dispersed powdered combustible material is present in high-enough concentrations in the atmosphere or other oxidizing gaseous medium, such as pure oxygen. In cases when fuel plays the role of a combustible material, the explosion is known as a fuel-air explosion. Dust explosions are a frequent hazard in coal mines, grain elevators, and other industrial environments. They are also commonly used by special effects artists, filmmakers, and pyrotechnicians, given their spectacular appearance and ability to be safely contained under certain carefully controlled conditions. Thermobaric weapons exploit this principle by rapidly saturating an area with an easily combustible material and then igniting it to produce explosive force. These weapons are the most powerful non-nuclear weapons in existence. Terminology If rapid combustion occurs in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining Accident
A mining accident is an accident that occurs during the process of mining minerals or metals. Thousands of miners die from mining accidents each year, especially from underground coal mining, although accidents also occur in hard rock mining. Coal mining is considered much more hazardous than hard rock mining due to flat-lying rock strata, generally incompetent rock, the presence of methane gas, and coal dust. Most of the deaths these days occur in developing countries, and rural parts of developed countries where safety measures are not practiced as fully. A mining disaster is an incident where there are five or more fatalities. Causes Mining accidents can occur from a variety of causes, including leaks of poisonous gases such as hydrogen sulfide or explosive natural gases, especially firedamp or methane, dust explosions, collapsing of mine stopes, mining-induced seismicity, flooding, or general mechanical errors from improperly used or malfunctioning mining equipment (suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
