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Jig Concentrators
Jig concentrators are devices used mainly in the mining industry for mineral processing, to separate particles within the ore body, based on their specific gravity (relative density). The particles would usually be of a similar size, often crushed and screened prior to being fed over the jig bed. There are many variations in design; however the basic principles are constant: The particles are introduced to the jig bed (usually a screen) where they are thrust upward by a pulsing water column or body, resulting in the particles being suspended within the water. As the pulse dissipates, the water level returns to its lower starting position and the particles once again settle on the jig bed. As the particles are exposed to gravitational energy whilst in suspension within the water, those with a higher specific gravity (density) settle faster than those with a lower count, resulting in a concentration of material with higher density at the bottom, on the jig bed. The particles are now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining Industry
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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Processing
In the field of extractive metallurgy, mineral processing, also known as ore dressing, is the process of separating commercially valuable minerals from their ores. History Before the advent of heavy machinery the raw ore was broken up using hammers wielded by hand, a process called "spalling". Before long, mechanical means were found to achieve this. For instance, stamp mills were used in Samarkand as early as 973. They were also in use in medieval Persia. By the 11th century, stamp mills were in widespread use throughout the medieval Islamic world, from Islamic Spain and North Africa in the west to Central Asia in the east. A later example was the Cornish stamps, consisting of a series of iron hammers mounted in a vertical frame, raised by cams on the shaft of a waterwheel and falling onto the ore under gravity. The simplest method of separating ore from gangue consists of picking out the individual crystals of each. This is a very tedious process, particularly when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Gravity
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), water at its densest (at ); for gases, the reference is air at room temperature (). The term "relative density" (often abbreviated r.d. or RD) is often preferred in scientific usage, whereas the term "specific gravity" is deprecation, deprecated. If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water, then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. A substance wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jig Bed
The jig ( ga, port, gd, port-cruinn) is a form of lively folk dance in compound metre, as well as the accompanying dance tune. It is most associated with Irish music and dance. It first gained popularity in 16th-century Ireland and parts of Great Britain and was quickly adopted on mainland Europe where it eventually became the final movement of the mature Baroque dance suite (the French gigue; Italian and Spanish giga). Today it is most associated with Irish dance music, Scottish country dance and the Métis people in Canada. Jigs were originally in duple compound metre, (e.g., time), but have been adapted to a variety of time signatures, by which they are often classified into groups, including double jigs (), slip jigs () and single jigs (). Origins The term ''jig'' was probably derived from the French ''giguer'', meaning ‘to jump’ or the Italian ''giga''. The use of “jig” in Irish dance derives from the Irish ''jigeánnai'', itself borrowed from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Energy
Gravitational energy or gravitational potential energy is the potential energy a massive object has in relation to another massive object due to gravity. It is the potential energy associated with the gravitational field, which is released (converted into kinetic energy) when the objects fall towards each other. Gravitational potential energy increases when two objects are brought further apart. For two pairwise interacting point particles, the gravitational potential energy U is given by U = -\frac, where M and m are the masses of the two particles, R is the distance between them, and G is the gravitational constant. Close to the Earth's surface, the gravitational field is approximately constant, and the gravitational potential energy of an object reduces to U = mgh where m is the object's mass, g = / is the gravity of Earth, and h is the height of the object's center of mass above a chosen reference level. Newtonian mechanics In classical mechanics, two or more masse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal
Coal is a combustible black or brownish-black sedimentary rock, formed as stratum, rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian (geology), Pennsylvanian) and Permian times. Many significant coal deposits are younger than this and originate from the Mesozoic and Cenozoic eras. Coal is used primarily as a fuel. While coal has been known and used for thousands of years, its usage was limited until the Industrial Revolution. With the invention of the steam engine, coal consumption increased. In 2020, coal supplied about a quarter of the world's primary energ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Jig
In metallurgy, mineral jigs are a type of gravity concentrator, separating materials with different densities. It is widely used in recovering valuable heavy minerals such as gold, platinum, tin, tungsten, as well as gemstones such as diamond and sapphire, from alluvial or placer deposits. Base metals such as iron, manganese, and barite can also be recovered using jigs. The process begins with flowing a stream of liquid-suspended material over a screen and subjecting the screen to a vertical hydraulic pulsation. This pulsation momentarily expands or dilates the screen bed and allows the heavier materials to work toward the bottom. Heavier material finer than the screen openings will gradually work through the beds and the retention screen into the hutch, or lower compartment. That material, the concentrate, is discharged from this compartment or hutch through a spigot. If the concentrate is coarser than the screen, it will work down to the top of the shot bed, and can be wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
