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Blast Furnace
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheric pressure. In a blast furnace, fuel ( coke), ores, and flux ( limestone) are continuously supplied through the top of the furnace, while a hot blast of air (sometimes with oxygen enrichment) is blown into the lower section of the furnace through a series of pipes called tuyeres, so that the chemical reactions take place throughout the furnace as the material falls downward. The end products are usually molten metal and slag phases tapped from the bottom, and waste gases ( flue gas) exiting from the top of the furnace. The downward flow of the ore along with the flux in contact with an upflow of hot, carbon monoxide-rich combustion gases is a countercurrent exchange and chemical reaction process. In contrast, air furnaces (such as reve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alto Horno, Puerto De Sagunto, España, 2015-01-04, DD 91
The musical term alto, meaning "high" in Italian (Latin: ''altus''), historically refers to the contrapuntal part higher than the tenor and its associated vocal range. In 4-part voice leading alto is the second-highest part, sung in choruses by either low women's or high men's voices. In vocal classification these are usually called contralto and male alto or countertenor. Such confusion of "high" and "low" persists in instrumental terminology. Alto flute and alto trombone are respectively lower and higher than the standard instruments of the family (the standard instrument of the trombone family being the tenor trombone), though both play in ranges within the alto clef. Alto recorder, however, is an octave higher, and is defined by its relationship to tenor and soprano recorders; alto clarinet is a fifth lower than B-flat clarinet, already an 'alto' instrument. There is even a contra-alto clarinet, (an octave lower than the alto clarinet), with a range B♭0 – D4. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Countercurrent Exchange
Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some chemical, between two flowing bodies flowing in opposite directions to each other. The flowing bodies can be liquids, gases, or even solid powders, or any combination of those. For example, in a distillation column, the vapors bubble up through the downward flowing liquid while exchanging both heat and mass. The maximum amount of heat or mass transfer that can be obtained is higher with countercurrent than co-current (parallel) exchange because countercurrent maintains a slowly declining difference or gradient (usually temperature or concentration difference). In cocurrent exchange the initial gradient is higher but falls off quickly, leading to wasted potential. For example, in the adjacent diagram, the fluid being heated (exiting top) has a higher exiting temperature than the cooled fluid (exiting bottom) that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of Ohio - DPLA - Aaba7b3295ff6973b6fd1e23e33cde14 (page 111) (cropped2)
Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of Earth. The first recorded use of the word γεωγραφία was as a title of a book by Greek scholar Eratosthenes (276–194 BC). Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be. While geography is specific to Earth, many concepts can be applied more broadly to other celestial bodies in the field of planetary science. One such concept, the first law of geography, proposed by Waldo Tobler, is "everything is related to everything else, but near things are more related than distant things." Geography has been called "the world discipline" and "the bridge between the human a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhouse Gas Emissions
Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and large oil and gas companies, many state-owned by OPEC and Russia. Human-caused emissions have increased atmospheric carbon dioxide by about 50% over pre-industrial levels. The growing levels of emissions have varied, but it was consistent among all greenhouse gases (GHG). Emissions in the 2010s averaged 56 billion tons a year, higher than ever before. Electricity generation and transport are major emitters; the largest single source, according to the United States Environmental Protection Agency, is transportation, accounting for 27% of all USA greenhouse gas emissions. Deforestation and other changes in land use also emit carbon dioxide and methane. The largest source of anthropogenic methane emissions is agriculture, closely follow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Metals
A base metal is a common and inexpensive metal, as opposed to a precious metal such as gold or silver. In numismatics, coins often derived their value from the precious metal content; however, base metals have also been used in coins in the past and today. Specific definitions In contrast to noble metals, base metals may be distinguished by oxidizing or corroding relatively easily and reacting variably with diluted hydrochloric acid (HCl) to form hydrogen. Examples include iron, nickel, lead and zinc. Copper is also considered a base metal because it oxidizes relatively easily, although it does not react with HCl. In mining and economics, the term base metals refers to industrial non-ferrous metals excluding precious metals. These include copper, lead, nickel and zinc. The U.S. Customs and Border Protection agency is more inclusive in its definition of commercial base metals. Its list includes—in addition to copper, lead, nickel, and zinc—the following metals: iron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinter Plant
Sinter plants agglomerate iron ore fines (dust) with other fine materials at high temperature, to create a product that can be used in a blast furnace. The final product, a sinter, is a small, irregular nodule of iron mixed with small amounts of other minerals. The process, called sintering, causes the constituent materials to fuse to make a single porous mass with little change in the chemical properties of the ingredients. The purpose of sinter are to be used converting iron into steel. Sinter plants, in combination with blast furnaces, are also used in non-ferrous smelting. About 70% of the world's primary lead production is still produced using the sinter plant–blast furnace combination, and this combination was formerly often used in copper smelting (at the Electrolytic Refining and Smelting smelter in Wollongong, New South Wales, for example). History Many countries, including India, France and Germany, have underground deposits of iron ore in dust form (blue dust). S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Ore
Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the form of magnetite (, 72.4% Fe), hematite (, 69.9% Fe), goethite (, 62.9% Fe), limonite (, 55% Fe) or siderite (, 48.2% Fe). Ores containing very high quantities of hematite or magnetite (greater than about 60% iron) are known as "natural ore" or "direct shipping ore", meaning they can be fed directly into iron-making blast furnaces. Iron ore is the raw material used to make pig iron, which is one of the main raw materials to make steel—98% of the mined iron ore is used to make steel. In 2011 the ''Financial Times'' quoted Christopher LaFemina, mining analyst at Barclays Capital, saying that iron ore is "more integral to the global economy than any other commodity, except perhaps oil". Sources Metallic iron is virtually unk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelt Mill
Smeltmills were water-powered mills used to smelt lead or other metals. The older method of smelting lead on wind-blown bole hills began to be superseded by artificially-blown smelters. The first such furnace was built by Burchard Kranich at Makeney, Derbyshire in 1554, but produced less good lead than the older bole hill. William Humfrey (the Queen's assay master), and a leading shareholder in the Company of Mineral and Battery Works introduced the ore hearth from the Mendips about 1577. This was initially blown by a foot-blast, but was soon developed into a water-powered smelt mill at Beauchief (now a suburb of Sheffield Sheffield is a city in South Yorkshire, England, whose name derives from the River Sheaf which runs through it. The city serves as the administrative centre of the City of Sheffield. It is historically part of the West Riding of Yorkshire ...). A typical smelt mill had an orehearth and a slaghearth, the latter being used to reprocess slags from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blowing House
A blowing house or blowing mill was a building used for smelting tin in Cornwall and on Dartmoor in Devon, in South West England. Blowing houses contained a furnace and a pair of bellows that were powered by an adjacent water wheel, and they were in use from the early 14th century until they were gradually replaced by reverberatory furnaces in the 18th century. The remains of over 40 blowing houses have been identified on Dartmoor. History The blowing house method of smelting tin was probably introduced early in the 14th century to replace the earliest method of smelting which had to be done in two stages – a first smelting probably took place near to the tinworks and the roughly smelted metal was taken to a stannary town to be smelted again to produce the final refined product. Each of these smeltings was taxed separately until 1303 when they were replaced by a single tax on the finished product. It is likely that this tax change was due to the improved smelting process pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloomery
A bloomery is a type of metallurgical furnace once used widely for smelting iron from its oxides. The bloomery was the earliest form of smelter capable of smelting iron. Bloomeries produce a porous mass of iron and slag called a ''bloom''. The mix of slag and iron in the bloom, termed ''sponge iron'', is usually consolidated and further forged into wrought iron. Blast furnaces, which produce pig iron, have largely superseded bloomeries. Process A bloomery consists of a pit or chimney with heat-resistant walls made of earth, clay, or stone. Near the bottom, one or more pipes (made of clay or metal) enter through the side walls. These pipes, called ''tuyeres'', allow air to enter the furnace, either by natural draught or forced with bellows or a trompe. An opening at the bottom of the bloomery may be used to remove the bloom, or the bloomery can be tipped over and the bloom removed from the top. The first step taken before the bloomery can be used is the preparati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
