|
Tailings
In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. Waste valorization is the evaluation of waste and residues from an economic process in order to determine their value in reuse or recycling, as what was gangue at the time of separation may increase with time or more sophisticated recovery processes. 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 partic ... [...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 Tailings Dam, Syncrude Mildred Lake Tailings Dyke in Alberta, Canada, is an embankment dam about long and from high. The dam and the artificial lake within it are constructed and maintained as part of ongoing operations by Syncrude in extracting oil from the Athabasca oil sands; 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 Hydroelectricity#Conventional (dams), hydroelectric dams. Tailings dams are design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Polley Disaster
Mount Polley mine is a Canadian gold and copper mine located in British Columbia near the towns of Williams Lake and Likely. It consists of two open-pit sites with an underground mining component and is owned and operated by the Mount Polley Mining Corporation, a wholly owned subsidiary of Imperial Metals. In 2013, the mine produced an output of of copper, 45,823 ounces of gold, and 123,999 of silver. The mill commenced operations in 1997 and was closed and placed on care and maintenance in 2019. The company owns of property near Quesnel Lake and Polley Lake where it has mining leases and operations on and mineral claims on . Mineral concentrate is delivered by truck to the Port of Vancouver. As of January 2020, Mount Polley's Proven and Probable Reserves were 53.8 million tonnes of ore grading 0.34% copper, 0.30 grams per tonne gold and 0.9 grams per tonne silver, equating to 400 million pounds of copper, 517,000 troy ounces of gold and 1.55 million troy ounces of silver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental Effects Of Mining
Environmental impact of mining can occur at local, regional, and global scales through direct and indirect mining practices. Mining can cause erosion, sinkholes, Biodiversity loss, loss of biodiversity, or the Soil contamination, contamination of soil, Groundwater pollution, groundwater, and surface water by chemicals emitted from mining processes. These processes also affect the atmosphere through carbon emissions which contributes to climate change. 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. Mining can provide various advantages to societies, yet it can also spark conflicts, particularly regarding land use both above and below the surface. Mining operations r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasibly created Chemical synthesis, artificially in a laboratory or factory. Ores recovered by mining include Metal#Extraction, metals, coal, oil shale, gemstones, limestone, chalk mining, chalk, dimension stone, rock salt, potash, gravel, and clay. The ore must be a rock or mineral that contains valuable constituent, can be extracted or mined and sold for profit. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even fossil water, water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, and final mine reclamation, reclamation or restoration of the land after the mine is closed. Mining ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gangue
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, 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 Underground mining (hard rock), mined from hard rock, the ore-bearing rock first needs to be crushed very finely, and then has to be subjected to sophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waste Valorization
Waste valorization, beneficial reuse, beneficial use, value recovery or waste reclamation is the process of waste products or Residue (chemistry), residues from an economic process being Valorisation, valorized (given economic value), by reuse or recycling in order to create economically useful materials. The term comes from practices in Manufacturing, sustainable manufacturing and Sustainable Economics, economics, industrial ecology and waste management. The term is usually applied in industrial processes where residue from creating or processing one good is used as a raw material or energy feedstock for another industrial process. Industrial wastes in particular are good candidates for valorization because they tend to be more consistent and predictable than other waste, such as household waste. Historically, most industrial processes treated waste products as something to be disposed of, causing Industrial Pollution, industrial pollution unless handled properly. However, increase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Processing
Mineral processing is the process of separating commercially valuable minerals from their ores in the field of extractive metallurgy. Depending on the processes used in each instance, it is often referred to as ore dressing or ore milling. Beneficiation is any process that improves (benefits) the economic value of the ore by removing the gangue minerals, which results in a higher grade product (ore concentrate) and a waste stream (tailings). There are many different types of beneficiation, with each step furthering the concentration of the original ore. Key is the concept of recovery (mineral processing), recovery, the mass (or equivalently molar) fraction of the valuable mineral (or metal) extracted from the ore and carried across to the concentrate. History Before the advent of heavy machinery, raw ore was broken up using hammers wielded by hand, a process called "''spalling''". Eventually, mechanical means were found to achieve this. For instance, stamp mills were being ... [...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 and 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 or highway construction) 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. These, combined with reduced pH, have a detrimental impact on the streams' aquatic environments. The same type of chemical reactions and processes may occur through the disturbance of acid sulfate soils formed under coastal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overburden
In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally finely milled ore. Overburden is removed during surface mining, but is typically not contaminated with toxic components. Overburden may also be used to restore an exhausted mining site during reclamation. Interburden is material that lies between two areas of economic interest, such as the material separating coal seams within strata.Peng, Syd S. (1986) ''Coal Mine Ground Control'' (2nd edition), Wiley, New York, page 303, Analogous uses Overburden is also used for all soil and ancillary material above the bedrock horizon in a given area. By analogy, overburden is also used to describe the soil and other material that lies a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waste
Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor Value (economics), economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product's value above zero. Examples include municipal solid waste (household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others. Definitions What constitutes waste depends on the eye of the beholder; one person's waste can be a resource for another person. Though waste is a physical object, its generation is a physical and psychological process. The definitions used by various agencies are as below. United Nations Environment Program According to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element; it has chemical symbol, 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 radioactive decay, radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes of uranium, isotopes, making them useful for dating the age of the Earth. 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 primordial nuclide, 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 notation#Parts-per expressions, parts per million in soil, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recycling
Recycling is the process of converting waste materials into new materials and objects. This concept often includes the recovery of energy from waste materials. The recyclability of a material depends on its ability to reacquire the properties it had in its original state. It is an alternative to "conventional" waste disposal that can save material and help lower greenhouse gas emissions. It can also prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, reducing energy use, air pollution (from incineration) and water pollution (from landfilling). Recycling is a key component of modern waste reduction and represents the third step in the "Reduce, Reuse, and Recycle" waste hierarchy, contributing to environmental sustainability and resource conservation. It promotes environmental sustainability by removing raw material input and redirecting waste output in the economic system. There are some ISO standards related to recycling, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
