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Tailings
In mining, tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different to overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. The extraction of minerals from ore can be done two ways: placer mining, which uses water and gravity to concentrate the valuable minerals, or hard rock mining, which pulverizes the rock containing the ore and then relies on chemical reactions to concentrate the sought-after material. In the latter, the extraction of minerals from ore requires comminution, i.e., grinding the ore into fine particles to facilitate extraction of the target element(s). Because of this comminution, tailings consist of a slurry of fine particles, ranging from the size of a grain of sand to a few micrometres. Mine tailings are usually produced from the mill in slurry form, which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tailings Dam
A tailings dam is typically an earth-fill embankment dam used to store byproducts of mining operations after separating the ore from the gangue. Tailings can be liquid, solid, or a slurry of fine particles, and are usually highly toxic and potentially radioactive. Solid tailings are often used as part of the structure itself. Tailings dams rank among the largest engineered structures on earth. The Syncrude Mildred Lake Tailings Dyke in Alberta, Canada, is an embankment dam about long and from high. It is the largest dam structure on earth by volume, and as of 2001 it was believed to be the largest earth structure in the world by volume of fill. There are key differences between tailings dams and the more familiar hydroelectric dams. Tailings dams are designed for permanent containment, meaning they are intended to "remain there forever". Copper, gold, uranium and other mining operations produce varied kinds of waste, much of it toxic, which pose varied challenges for long-term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental Effects Of Mining
Environmental effects of mining can occur at local, regional, and global scales through direct and indirect mining practices. The effects can result in erosion, sinkholes, Biodiversity loss, loss of biodiversity, or the Soil contamination, contamination of soil, Groundwater pollution, groundwater, and surface water by the chemicals emitted from mining processes. These Process chemistry, processes also affect the atmosphere from the emissions of carbon which have an effect on the quality of human health and biodiversity. Some mining methods (lithium mining, Phosphate mineral, phosphate mining, coal mining, mountaintop removal mining, and sand mining) may have such significant environmental and public health effects that mining companies in some countries are required to follow strict environmental and rehabilitation codes to ensure that the mined area returns to its original state. Erosion Erosion of exposed hillsides, mine dumps, tailings dams and resultant siltation of draina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided. All known thorium isotopes are unstable. The most stable isotope, 232Th, has a half-life of 14.05 billion years, or about the age of the universe; it decays very slowly via alpha decay, starting a decay chain named the thorium series that ends at stable 208 Pb. On Earth, thorium and uranium are the only significantly radioactive elements that still occur naturally in large quantities as primordial elements. Thorium is estimated to be over three times as abundant as uranium in the Earth's crust, and is chiefly refined from monazite sands as a by-product of extracti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Mine Drainage
Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines or coal mines. Acid rock drainage occurs naturally within some environments as part of the rock weathering process but is exacerbated by large-scale earth disturbances characteristic of mining and other large construction activities, usually within rocks containing an abundance of sulfide minerals. Areas where the earth has been disturbed (e.g. construction sites, subdivisions, and transportation corridors) may create acid rock drainage. In many localities, the liquid that drains from coal stocks, coal handling facilities, coal washeries, and coal waste tips can be highly acidic, and in such cases it is treated as acid rock drainage. This liquid often contains highly toxic metals, such as copper or iron. These, combined with reduced pH, have a detrimental impact on the streams aquatic environments. The same type of chemical reactions and pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gangue
In mining, gangue () is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. It is thus distinct from overburden, which is the waste rock or materials overlying an ore or mineral body that are displaced during mining without being processed, and from tailings, which is rock already stripped of valuable minerals. The separation of valuable mineral from gangue minerals is known as mineral processing, mineral dressing, or ore dressing. It is a necessary, and often significant, aspect of mining. It can be a complicated process, depending on the nature of the minerals involved. For example, galena, an ore of lead, is usually found in large pieces within its gangue, so it does not normally need extensive processing to remove it; but cassiterite, the chief ore mineral of tin, is usually disseminated as very small crystals throughout its gangue, so when it is mined from hard rock, the ore-bearing rock first needs to be crushed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groundwater Pollution
Groundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution. Groundwater pollution can occur from on-site sanitation systems, landfill leachate, effluent from wastewater treatment plants, leaking sewers, petrol filling stations, hydraulic fracturing (fracking) or from over application of fertilizers in agriculture. Pollution (or contamination) can also occur from naturally occurring contaminants, such as arsenic or fluoride. Using polluted groundwater causes hazards to public health through poisoning or the spread of disease (water-borne diseases). The pollutant often creates a contaminant plume within an aquifer. Movement of water and dispersion within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphogypsum
Phosphogypsum (PG) is the calcium sulfate hydrate formed as a by-product of the production of fertilizer from phosphate rock. It is mainly composed of gypsum (CaSO4·2H2O). Although gypsum is a widely used material in the construction industry, phosphogypsum is usually not used, but is stored indefinitely because of its weak radioactivity caused by the presence of naturally occurring uranium (U) and thorium (Th), and their daughter isotopes radium (Ra), radon (Rn) and polonium (Po). The long-range storage of phosphogypsum is controversial.Ayres, R. U., Holmberg, J., Andersson, B., "Materials and the Global environment: Waste Mining in the 21st Century", MRS Bull. 2001, 26, 477. About five tons of phosphogypsum are generated per ton of phosphoric acid production. Annually, the estimated generation of phosphogypsum worldwide is 100 to 280 million metric tons. Production and properties Phosphogypsum is a by-product from the production of phosphoric acid by treating phosphate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate Rock
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P2O5). Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P2O5. This occurs through washing, screening, de-liming, magnetic separation or flotation. By comparison, the average phosphorus content of sedimentary rocks is less than 0.2%.Blatt, Harvey and Robert J. Tracy, ''Petrology'', Freeman, 1996, 2nd ed. pp. 345–349 The phosphate is present as fluorapatite Ca5(PO4)3F typically in cryptocrystalline masses (grain sizes < 1 μm) referred to as -sedimentary apatite deposits of uncertain origin. It is also present as [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broken Hill Town & Line Of Lode Pano, NSW, 08
Broken may refer to: Literature * Broken (Armstrong novel), ''Broken'' (Armstrong novel), a 2006 novel by Kelley Armstrong in the ''Women of the Otherworld'' series * Broken (Slaughter novel), ''Broken'' (Slaughter novel), a 2010 novel by Karin Slaughter Music Albums * ''Broken (And Other Rogue States)'', a 2005 album by Luke Doucet * Broken (MBLAQ EP), ''Broken'' (MBLAQ EP) (2014) * Broken (Nine Inch Nails EP), ''Broken'' (Nine Inch Nails EP), (1992) * Broken (Soulsavers album), ''Broken'' (Soulsavers album) (2009) * Broken (Straight Faced album), ''Broken'' (Straight Faced album) (1996) Songs * Broken (Jake Bugg song), "Broken" (Jake Bugg song) (2013) * Broken (Sam Clark song), "Broken" (Sam Clark song) (2009) * Broken (Coldplay song), "Broken" (Coldplay song) (2019) * Broken (Elisa song), "Broken" (Elisa song) (2003) * Broken (Lifehouse song), "Broken" (Lifehouse song) (2008) * Broken (lovelytheband song), "Broken" (lovelytheband song) (2017) * Broken (Kate Ryan son ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all isotopes of uranium are unstable; the half-lives of its naturally occurring isotopes range between 159,200 years and 4.5 billion years. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead, and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238 (99. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daughter Isotope
In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps (decay chain). For example, 238U decays to 234Th which decays to 234mPa which decays, and so on, to 206Pb (which is stable): : \ce \overbrace^\ce left, upThe decay chain from lead-212 down to lead-208, showing the intermediate decay products In this example: * 234Th, 234mPa,...,206Pb are the decay products of 238U. * 234Th is the daughter of the parent 238U. * 234mPa (234 metastable) is the granddaughter of 238U. These might also be referred to as the daughter products of 238U. (''Depleted Uranium'' — authors: Naomi H. Harley, Ernest C. Foulkes, Lee H. Hil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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