mining extraction britannica

Mining - Underground mining | Britannica.com

The openings made in the process of extracting ore are called stopes or rooms. There are two steps involved in stoping. The first is development—that is, preparing the ore blocks for mining—and the second is production, or stoping, itself. Ore development is generally much more expensive on a per-ton basis than stoping,...

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Mining | Britannica.com - Encyclopedia Britannica

Mining, process of extracting useful minerals from the surface of the Earth, including the seas. A mineral, with a few exceptions, is an inorganic substance occurring in nature that has a definite chemical composition and distinctive physical properties or molecular structure. (One organic substance, coal, is often discussed as...

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niobium processing | History, Ores, Mining, & Extraction | Britannica ...

In 1844 Heinrich Rose, a German chemist, announced his discovery of an element that he named niobium, after Niobe, the mythical daughter of Tantalus (who in turn gave his name to tantalum, with which niobium is often associated in minerals). Niobium was later proved to be the same element as columbium, and niobium...

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Coal mining - Choosing a mining method | Britannica.com

The various methods of mining a coal seam can be classified under two headings, surface mining and underground mining. 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...

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Surface mining | Britannica.com

Surface mining: Surface mining, method of extracting minerals near the surface of the Earth. The three most common types of surface mining are open-pit mining, strip mining, and quarrying. See also mining and coal.

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Strip mining | Britannica.com

The cycle of operations for both techniques consists of vegetation clearing, soil removal, drilling and blasting of overburden (if needed), stripping, removal of the coal or other mineral commodity, and reclamation. Area mining is appropriate for the extraction of near-surface, relatively flat-lying, and thin deposits of coal,...

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Ore | mining | Britannica.com

Generally, the ore and the gangue are mined together—i.e., taken out of the host rock in a mass by either mechanical or manual means. Then the ore is separated from the gangue by various operations known collectively as mineral processing, or ore dressing. The desired metallic element is then extracted from the ore by...

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Mining - Solution mining | Britannica.com

Mining - Solution mining: Natural brine wells are the source of a large percentage of the world's bromine, lithium, and boron and lesser amounts of potash, trona ... the same basic geometry is used, but the fresh water is injected through the suspended tube at the bottom of the formation, and the brine is extracted through the...

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Quarry | mining | Britannica.com

Dimension stones are extracted in a highly selective manner, using time-consuming and expensive methods for freeing the blocks from the surrounding rock. portland stone quarryPortland stone quarry, Isle of Portland, Dorset, Eng. Mark A. Wilson. Sand, gravel, and crushed rock quarries employ standard surface-mining...

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Thick-seam mining | Britannica.com

Thick-seam mining: Coal seams as much as five metres thick can be mined in a single “lift” by the longwall method, and seams up to seven metres thick have been extracted by conventional mining systems in one pass. However, when a seam exceeds these thicknesses,…

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Silver processing | Britannica.com

Extraction and refining. The specific extractive metallurgy processes applied to a silver-bearing mineral concentrate depend on whether the major metal is copper, zinc, or lead.

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copper processing | Definition, History, & Facts | Britannica.com

Definite records have been found of the working of copper mines on the Sinai Peninsula about 3800 bce, and the discovery of crucibles at these mines indicates that the art of extracting the metal included some refining. Copper was hammered into thin sheets, and the sheets were formed into pipes and other objects. During...

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Mercury processing | Britannica.com

Various vertical furnaces have been used to extract quicksilver since the earliest known crude furnaces were used at the Almadén Mine in Spain in the 12th century. The most common furnace in use in Europe is the Cermak-Spirek shaft furnace, which can treat either coarse feed (at least 4 centimetres, or 1.5 inches) or (with...

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Gold processing | Britannica.com

By 2000 bc the process of purifying gold-silver alloys with salt to remove the silver was developed. The mining of alluvial deposits and, later, lode or vein deposits required crushing prior to gold extraction, and this consumed immense amounts of manpower. By ad 100, up to 40,000 slaves were employed in gold mining in...

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Frasch process | mining | Britannica.com

Frasch process, method of mining deep-lying sulfur invented by the German-born American chemist Herman Frasch. The process involves superheating ... Frasch first successfully mined sulfur by this process at the Sulfur Mine in Louisiana in 1894. In 1895 the Union Sulphur ... use in sulfur extraction. In sulfur: Commercial...

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mining - Students | Britannica Kids | Homework Help

The branch of industry concerned with the search for, and extraction of, minerals from the Earth is called mining. The site in which minerals are found is usually called a mine—two exceptions are oil wells and rock quarries. The kinds of minerals dug from the Earth vary widely. They include the ores of iron, aluminum,...

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coal | Surface mining - Students | Britannica Kids | Homework Help

coal - Surface mining - Over the past 20 years, surface mining has become the most common method of extracting coal in the United States. Where feasible, surface mining is about three times more productive than underground mining. This is because the coal deposits lie closer to the surface and can be more easily...

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coal mining | Contour strip mining - Students | Britannica Kids ...

coal mining - Contour strip mining - Contour mining is commonly practiced where a coal seam outcrops in rolling or hilly terrain. Basically, the method consists of removing the overburden above the coal seam and then, starting at the outcrop and proceeding along the hillside, creating a bench around the hill. In the past, the...

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shaft mine: types of mines - Students | Britannica Kids | Homework ...

The diagram depicts a cross section of three different kinds of mines, along with structural elements of the underground shaft and slope mines. The shaft mine has compartments for a skip hoist, elevators called cages, and service facilities such as ventilation ducts. In a slope mine, the miners also work at different levels, and...

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Geological and Mining Engineering - Britannica Kids

engineering - Geological and Mining Engineering - The field of geological and mining engineering deals with the discovery and exploration of mineral deposits, the various processes to extract these minerals, and their conversion into useful metals or other refined products. Mining engineers are responsible for the safe,...

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Mining Jobs Canada | Geologist Jobs, Heavy Mechanic Jobs, Truck ...

Quarry Mining Jobs: Quarry mining involves the extraction of aggregate and dimension stone. Miners may be looking for limestone, marble, slate, marble sandstone or granite. Crushed rock, sand and gravel quarries are quite common. Extraction requires the use of surface mining techniques (Britannica mining). Some of...

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1911 Encyclopædia Britannica/Diamond - Wikisource, the free ...

Feb 19, 2013 ... 8); material is thus continually withdrawn from one side of the mine and extracted by means of the rock shaft on the opposite side, while the superincumbent débris is continually sinking, and is allowed to fall deeper on the side farthest from the shaft as the blue ground is withdrawn from beneath it. In 1905...

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mine in Spanish | English-Spanish translator | Nglish by Britannica

How to say mine in Spanish - Translation of mine to Spanish by Nglish, comprehensive English – Spanish Dictionary, Translation and English learning by Britannica. Example sentences: the soldiers were careful to disarm any mines they found in their path.

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Subterranea Britannica: Sites: Cae Coch Sulphur Mine

Jan 4, 2011 ... Those figures were never achieved again but production remained steady until Veitch left the mine in 1895, by which date a total of 81,634 tons of pyrites had been extracted since his arrival in 1880. During this period Veitch tried to sell the mine on three occasions finally selling it at the third attempt to the...

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Subterranea Britannica: Sites:Boulby Potash Mine

The high value potash is the object of the mine, although for reasons explained below rock salt has also to be mined to reach it. At this locality, it would be uneconomic to mine the underlying anhydrite or gypsum: these more widespread minerals are extracted from shallower mines in the Derbyshire / Nottinghamshire, East...

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数据挖掘- 维基百科,自由的百科全书

数据挖掘(英语:data mining)是一个跨学科的计算机科学分支 它是用人工智能、机器学习、统计学和数据库的交叉方法在相對較大型的数据集(英语:data set)中发现模式的计算过程。数据挖掘过程的总体目标是从一个数据集中提取信息,并将其转换成可理解的结构,以进一步使用。除了原始分析步骤,它还涉及到数据库和数据管理...

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Data mining - Wikipedia

Data mining is the process of discovering patterns in large data sets involving methods at the intersection of machine learning, statistics, and database systems. It is an essential process where intelligent methods are applied to extract data patterns. It is an interdisciplinary subfield of computer science. The overall goal of the...

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SBA Energy and Mineral Resource Management - Group on Earth ...

CA-06 Energy and Mineral Resources Management. 3. Minerals: a global issue… http://www.mining.com/infographic-where-the-minerals-are-82638/. Mining: a global issue… Coal and Lignite a global issue too… http://media.web.britannica.com/eb-media/14/105414-050-2AB4F88F.gif. "Unused extraction" grows

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Wikipedia Link Structure and Text Mining for Semantic Relation ...

encyclopedia Britannica contains only 65,000 articles. As a corpus for knowledge extraction, Wikipedia's impressive characteristics are not limited to the scale, but also include the dense link structure, sense disambiguation based on URL, brief link texts and well structured sentences. The fact that these characteristics are...

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Mining meaning from Wikipedia - Research Commons - University of ...

Nov 9, 2001 ... Traditional approaches to mining meaning fall into two broad camps. ... information extraction and ontology building—mining text for topics, relations and ..... Britannica. Both sources were equally prone to significant errors, such as misinterpretation of important concepts. More subtle errors, however, such...

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Catching the Red Priest - Association for Computational Linguistics

clopaedia Britannica. Throughout their existence, encyclopedias have claimed to be well-organized. (i.e., structured) representations of knowledge and have effectively served .... mining a historical corpus for trends using the fre- quentist approaches ... mentation, people article extraction, and article matching. For the case...

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Mining industry and sustainable development: time for change ...

Jun 9, 2017 ... With time, mining have expanded and increasing amounts of fossil fuels (e.g. coal) and metals (e.g. iron) were extracted in quantities generally commensurate with man power available and thus with human population over the centuries. With technological developments, especially with explosives and...

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The Project Gutenberg eBook of Encyclopædia Britannica, Volume ...

8); material is thus continually withdrawn from one side of the mine and extracted by means of the rock shaft on the opposite side, while the superincumbent débris is continually sinking, and is allowed to fall deeper on the side farthest from the shaft as the blue ground is withdrawn from beneath it. In 1905 the main shaft had...

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Extract | Definition of Extract by Merriam-Webster

Synonyms of extract from the Merriam-Webster Thesaurus, with definitions, antonyms, and related words. Find a better way to say it.

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Mining on the Iron Range | Minnesota Digital Library

Initially, miners extracted the iron ore using hand tools such as pick axes and shovels, but later used increasingly mechanized equipment. The ore was then ... Iron ore mining has had a lasting impact on Minnesota and helped to shape the state's industrial and cultural identity. ... Encyclopædia Britannica, Inc., 2016. Web.

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Mining Methods - Cochise College P

Mining by A. Nonymous Physical Geology Fall 2016. Mining Methods. There are Different types of mining methods the main two being, first, underground methods and the ... o Hydraulic-powered, or water powered, roof supports are used to hold the roof up until the mining extraction is over ... Encyclopedia Britannica Online.

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Mining on-line Sources for Definition Knowledge - Semantic Scholar

Mining on-line sources. A collection of texts is obtained from on-line resources: • WordNet: we extract all glosses and all hypernyms. (super-ordinate words) associated with the definiendum; this is done by using a WordNet interface implemented in. Gate. • Britannica: we retrieve all pages containing the definien- dum from...

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How Do You Process Silver? - YouTube

Jul 8, 2017 ... Silver processing how silver is made material, making, history, used, the process of mining hard dollar corporationhow to extract from mine ... hard ore 18 dec 2016 silver is quite different from gold because it nearly always found within ores that require specialized mining techniques extract. Britannica

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Surface Mining - RitchieWiki

Sep 28, 2010 ... Surface mining is the process of extracting minerals and ores located in close proximity to the surface of the earth. A layer of soil, subsoil, and strata are removed to gain access to the minerals and ore. Subsurface mining is a variation of surface mining in which the ore or minerals are extracted from a...

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Fairphone Urban Mining Manual: Leader's Guide

Urban Mining Manual: Leader's Guide. Aim. Urban mining refers to the extraction of minerals from existing products. This leader's guide will take you through preparing a practical lesson on urban mining a mobile phone in a classroom or workshop. Objective. The students or working group will take apart old (and no longer...

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