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Mining In Ancient Rome
Mines in ancient Rome used hydraulic mining and shaft mining techniques with tools such as the Archimedes screw. The materials they produced were used to craft pipes or construct buildings. Quarries were often built through trial trenching and they used tools such as wedges to break the rock apart, which would then be transported using cairns and slipways. Mines typically used slaves and lower-class individuals to extract and process ore. Usually their working conditions were dangerous and inhumane, resulting in frequent accidents and even suicidal ideation. These areas were divided into districts and were regulated by several laws such as the '' lex metalli vispascensis''. Technology Hydraulic mining The Romans used a technique known as hushing, which is a method of hydraulic mining that uses water to erode the rock. This would be accomplished by using holes to funnel water into the area, thus breaking it up. The water was supplied to the area through aqueducts, it wou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rosia Montana Roman Gold Mines 2011 - Small Entrance Close Up
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Roman Aqueduct
The Romans constructed aqueducts throughout their Republic and later Empire, to bring water from outside sources into cities and towns. Aqueduct water supplied public baths, latrines, fountains, and private households; it also supported mining operations, milling, farms, and gardens. Aqueducts moved water through gravity alone, along a slight overall downward gradient within conduits of stone, brick, concrete or lead; the steeper the gradient, the faster the flow. Most conduits were buried beneath the ground and followed the contours of the terrain; obstructing peaks were circumvented or, less often, tunneled through. Where valleys or lowlands intervened, the conduit was carried on bridgework, or its contents fed into high-pressure lead, ceramic, or stone pipes and siphoned across. Most aqueduct systems included sedimentation tanks, which helped to reduce any water-borne debris. Sluices, ''castella aquae'' (distribution tanks) and stopcocks regulated the supply to individual de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation (mining)
Underground mine ventilation provides a flow of air to the underground workings of a mine of sufficient volume to dilute and remove dust and noxious gases (typically NOx, SO2, methane, CO2 and CO) and to regulate temperature. The source of these gases are equipment that runs on diesel engines, blasting with explosives, and the orebody itself. The largest component of the operating cost for mine ventilation is electricity to power the ventilation fans, which may account for one third of a typical underground mine's entire electrical power cost. Types of ventilation Flow-through ventilation is the main ventilation circuit for the mine. Air enters the mine from surface via a shaft, ventilation raise or adit. The air is distributed through the mine via internal ventilation raises and ramps, and flows are controlled by regulators and permanently mounted ventilation fans. An auxiliary ventilation system takes air from the flow-through system and distributes it to the mine wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adit
An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adits are also used to explore for mineral veins. Construction Adits are driven into the side of a hill or mountain, and are often used when an ore body is located inside the mountain but above the adjacent valley floor or coastal plain. In cases where the mineral vein outcrops at the surface, the adit may follow the lode or vein until it is worked out, in which case the adit is rarely straight. The use of adits for the extraction of ore is generally called drift mining. Adits can only be driven into a mine where the local topography permits. There will be no opportunity to drive an adit to a mine situated on a large flat plain, for instance. Also if the ground is weak, the cost of shoring up a long adit may outweigh its possible advantage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Wheel
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets arranged on the outside rim forming the driving car. Water wheels were still in commercial use well into the 20th century but they are no longer in common use. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth. Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace. Waterwheels were used for various purposes from ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Mining
Silver mining is the extraction of silver from minerals, starting with mining. Because silver is often found in intimate combination with other metals, its extraction requires elaborate technologies. In 2008, ca.25,900 metric tons were consumed worldwide, most of which came from mining. Silver sources Silver-bearing ore typically contains very little silver, with much higher percentages of copper and lead. Specific minerals include argentite (Ag2 S), chlorargyrite ("horn silver," Ag Cl), polybasite (Ag, Cu)16Sb2S11), and proustite (Ag3AsS3). Silver mainly occurs as a contaminant in chalcopyrite and galena, important ores of copper and lead, respectively.Kassianidou, V. 2003. Early Extraction of Silver from Complex Polymetallic Ores, in Craddock, P.T. and Lang, J (eds) Mining and Metal production through the Ages. London, British Museum Press: 198–206 Some ores are actually mined explicitly for their silver value vs the silver being a byproduct of other metals. However ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Highly Toxic Gases
Many gases have toxic properties, which are often assessed using the LC50 (median lethal dose) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits ( TLV, TWA or STEL) determined by the ACGIH professional association. Some, but by no means all, toxic gases are detectable by odor, which can serve as a warning. Among the best known toxic gases are carbon monoxide, chlorine, nitrogen dioxide and phosgene. Definition *Toxic: it is a chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats weighing between 200 and 300 grams each. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation (architecture)
Ventilation is the intentional introduction of outdoor air into a space. Ventilation is mainly used to control indoor air quality by diluting and displacing indoor pollutants; it can also be used to control indoor temperature, humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of indoor environment, or other objectives. The intentional introduction of outdoor air is usually categorized as either mechanical ventilation, natural ventilation, or mixed-mode ventilation (hybrid ventilation). * Mechanical ventilation is the intentional fan driven flow of outdoor air into a building. Mechanical ventilation systems may include supply fans (which push outdoor air into a building), exhaust fans (which draw air out of building and thereby cause equal ventilation flow into a building), or a combination of both. Mechanical ventilation is often provided by equipment that is also used to heat and cool a space. * Natural ventilation is the intentional passive fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaft (civil Engineering)
In civil engineering a shaft is an underground vertical or inclined passageway. Shafts are often entered through a manhole and closed by a manhole cover. They are constructed for a number of reasons including: * For the construction of a tunnel * For ventilation of a tunnel or underground structure, aka ventilation shaft * As a drop shaft for a sewerage or water tunnel * For access to a tunnel or underground structure, also as an escape route Construction There are a number of methods for the construction of shafts, the most significant being: * The use of sheet piles, diaphragm walls or bored piles to construct a square or rectangular braced shaft * The use of segmental lining installed by underpinning In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons: * The original foundation isn't strong or stable enough. ... or caisson sunk to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Bed
A stream bed or streambed is the bottom of a stream or river (bathymetry) or the physical confine of the normal water flow (Channel (geography), channel). The lateral confines or channel margins are known as the stream Bank (geography), banks or river banks, during all but flood stage. Under certain conditions a river can branch from one stream bed to multiple stream beds. A flood occurs when a stream overflows its banks and flows onto its flood plain. As a general rule, the bed is the part of the stream channel, channel up to the normal water line, and the banks are that part above the normal water line. However, because water flow varies, this differentiation is subject to local interpretation. Usually, the bed is kept clear of terrestrial vegetation, whereas the banks are subjected to water flow only during unusual or perhaps infrequent high water stages and therefore might support vegetation some or much of the time. The nature of any stream bed is always a function of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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