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Ventilation (mining)
Underground mine ventilation provides a flow of air to the underground mining, underground workers of a mine with sufficient volume to dilute and remove dust and Poison, noxious gases (typically NOx, NOx, Sulfur dioxide, SO2, methane, Carbon dioxide, CO2 and Carbon Monoxide, CO) and to regulate temperature. The source of these gases are equipment that runs on diesel engines, blasting with explosives, and the orebody itself. Regulations often require airflow to be distributed within mines to improve air quality. 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 the surface via a shaft mining, shaft, raise (mining), ventilation raise or adit. The air is distributed through the mine via internal ventilation raises ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venturies
The Venturi effect is the reduction in fluid pressure that results when a moving fluid speeds up as it flows from one section of a pipe to a smaller section. The Venturi effect is named after its discoverer, the Italian physicist Giovanni Battista Venturi, and was first published in 1797. The effect has various engineering applications, as the reduction in pressure inside the constriction can be used both for measuring the fluid flow and for moving other fluids (e.g. in a vacuum ejector). Background In inviscid fluid dynamics, an incompressible fluid's velocity must ''increase'' as it passes through a constriction in accord with the principle of mass continuity, while its static pressure must ''decrease'' in accord with the principle of conservation of mechanical energy (Bernoulli's principle) or according to the Euler equations. Thus, any gain in kinetic energy a fluid may attain by its increased velocity through a constriction is balanced by a drop in pressure because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hazard
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific ''incident'', combined with the magnitude of potential harm, make up its risk. This term is often used synonymously in colloquial speech. Hazards can be classified in several ways which are not mutually exclusive. They can be classified by ''causing actor'' (for example, natural or anthropogenic), by ''physical nature'' (e.g. biological or chemical) or by ''type of damage'' (e.g., health hazard or environmental hazard). Examples of natural disasters with highly harmful impacts on a society are floods, droughts, earthquakes, tropical cyclones, lightning strikes, volcanic activity and wildfires. Technological and anthropogenic hazards include, for example, structural collapses, transport accidents, acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contamination
Contamination is the presence of a constituent, impurity, or some other undesirable element that renders something unsuitable, unfit or harmful for the physical body, natural environment, workplace, etc. Types of contamination Within the sciences, the word "contamination" can take on a variety of subtle differences in meaning, whether the contaminant is a solid or a liquid, as well as the variance of environment the contaminant is found to be in. A contaminant may even be more abstract, as in the case of an unwanted energy source that may interfere with a process. The following represent examples of different types of contamination based on these and other variances. Chemical contamination In chemistry, the term "contamination" usually describes a single constituent, but in specialized fields the term can also mean chemical mixtures, even up to the level of cellular materials. All chemicals contain some level of impurity. Contamination may be recognized or not and may become a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation Shaft
In subterranean civil engineering, ventilation shafts, also known as airshafts or vent shafts, are vertical passages used in mines and tunnels to move fresh air underground, and to remove stale air. In architecture, an airshaft, also known as a lightwell, is typically a small, vertical space within a tall building which permits ventilation of the building's interior spaces to the outside. The floor plan of a building with an airshaft is often described as a "square donut" shape. Alternatively, an airshaft may be formed between two adjacent buildings. Windows on the interior side of the donut allow air from the building to be exhausted into the shaft, and, depending on the height and width of the shaft, may also allow extra sunlight inside. See also * Ventilation (architecture) * Stack effect * Underground mine ventilation * Courtyard * Lightwell * Skylight A skylight (sometimes called a rooflight) is a light-permitting structure or window, usually made of transpare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunnel
A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ventilation openings at various points along the length. A pipeline differs significantly from a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods. A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. The central portions of a rapid transit network are usually in the tunnel. Some tunnels are used as sewers or aqueducts to supply water for consumption or for hydroelectric stations. Utility tunnels are used for routing steam, chilled water, electrical power or telecommunication cables, as well as connecting buildings for convenient passage of people and equipment.Salazar, Waneta. ''Tunnels in Civil Engineering''. Delhi, India : Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet Bulb Temperature
The wet-bulb temperature is the lowest temperature that can be reached under current ambient conditions by the evaporation of water only. It is defined as the temperature of a parcel of air cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat supplied by the parcel. A wet-bulb thermometer indicates a temperature close to the true (thermodynamic) wet-bulb temperature. More formally, the wet-bulb temperature is the temperature an air parcel would have if cooled adiabatically to saturation at constant pressure by evaporation of water into it, all latent heat being supplied by the parcel. At 100% relative humidity, the wet-bulb temperature is equal to the air temperature (dry-bulb temperature); at lower humidity the wet-bulb temperature is lower than dry-bulb temperature because of evaporative cooling. Intuition If a thermometer is wrapped in a water-moistened cloth, it will behave differently. The drier and less humid the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanisivik Mine
Nanisivik Mine was a zinc-lead mine in the company town of Nanisivik, Nunavut, north of the Arctic Circle on Baffin Island. It was Canada's first mine in the Arctic. The mine first opened on 15 October 1976 and permanently closed in September 2002 due to low metal prices and declining resources. Mine reclamation began in April 2003. It was one of the most northerly mines in the world. The mine was served by a port and dock located about north. It was used for shipping concentrate from the site, and receiving supplies. It is currently used by the Canadian Coast Guard for training and is intended to become Nanisivik Naval Facility. The mine also had its own airport ( Nanisivik Airport) located about southwest and was the main airport for Arctic Bay, until they expanded the Arctic Bay Airport. The airport is about directly southeast of Arctic Bay but the road between them is . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raglan Mine
Raglan Mine is a large nickel mining complex in the Nunavik region of northern Quebec, Canada. It is located approximately south of Deception Bay. Discovery of the deposits is credited to Murray Edmund Watts in 1931 or 1932. It is owned and operated by Glencore Canada Corporation. The mine site is located in sub-arctic permafrost of the Cape Smith Belt, with an average underground temperature of . Transportation and accommodations The complex is served by and operates the Kattiniq/Donaldson Airport, which is east of the principal mine site. There is a gravel road leading from the mine site to the seaport in Deception Bay. It is the only road of any distance in the province north of the 55th parallel. As the complex is remote from even the region's Inuit communities, workers must lodge at the mine site, typically for weeks at a time. From the mine site employees are flown to Val D'or, or in the case of Inuit employees, their home community. Ore produced from the mine is mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permafrost
Permafrost () is soil or underwater sediment which continuously remains below for two years or more; the oldest permafrost has been continuously frozen for around 700,000 years. Whilst the shallowest permafrost has a vertical extent of below a meter (3 ft), the deepest is greater than . Similarly, the area of individual permafrost zones may be limited to narrow mountain summits or extend across vast Arctic regions. The ground beneath glaciers and ice sheets is not usually defined as permafrost, so on land, permafrost is generally located beneath a so-called active layer of soil which freezes and thaws depending on the season. Around 15% of the Northern Hemisphere or 11% of the global surface is underlain by permafrost, covering a total area of around . This includes large areas of Alaska, Canada, Greenland, and Siberia. It is also located in high mountain regions, with the Tibetan Plateau being a prominent example. Only a minority of permafrost exists in the Southern Hemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic
The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway (Nordland, Troms, Finnmark, Svalbard and Jan Mayen), northernmost Sweden (Västerbotten, Norrbotten and Lapland (Sweden), Lappland), northern Finland (North Ostrobothnia, Kainuu and Lapland (Finland), Lappi), Russia (Murmansk Oblast, Murmansk, Siberia, Nenets Autonomous Okrug, Nenets Okrug, Novaya Zemlya), the United States (Alaska), Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), and northern Iceland (Grímsey and Kolbeinsey), along with the Arctic Ocean and adjacent seas. Land within the Arctic region has seasonally varying cryosphere, snow and ice cover, with predominantly treeless permafrost under the tundra. Arctic seas contain seasonal sea ice in many places. The Arctic region is a unique area among Earth's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperateness
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small; they usually differ only in the amount of precipitation. In temperate climates, not only do latitudinal positions influence temperature changes, but various sea currents, prevailing wind direction, continentality (how large a landmass is) and altitude also shape temperate climates. The Köppen climate classification defines a climate as "temperate" C, when the mean temperature is above but below in the coldest month to account for the persistence of frost. However, some adaptations of Köppen set the minimum at . Continental climates are classified as D and considered to be varieties of temperate climates, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
