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Comminution
Comminution is the reduction of solid materials from one average particle size to a smaller average particle size, by crushing, grinding, cutting, vibrating, or other processes. In geology, it occurs naturally during faulting in the upper part of the Earth's crust. In industry, it is an important unit operation in mineral processing, ceramics, electronics, and other fields, accomplished with many types of mill. In dentistry, it is the result of mastication of food. In general medicine, it is one of the most traumatic forms of bone fracture. Within industrial uses, the purpose of comminution is to reduce the size and to increase the surface area of solids. It is also used to free useful materials from matrix materials in which they are embedded, and to concentrate minerals. Energy requirements The comminution of solid materials consumes energy, which is being used to break up the solid into smaller pieces. The comminution energy can be estimated by: * Rittinger's law, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fred Chester Bond
Fred Chester Bond (June 10, 1899 – January 23, 1977) was an American mining engineer. A graduate of the Colorado School of Mines, he worked in the mining equipment and ore milling equipment business of Allis-Chalmers from 1930 to 1964. Bond Work Index In the 1930s through early 1950s, Bond developed a new theory of comminution that introduced an index, called the 'Bond Work Index', which relates power consumption in crushing and grinding to the feed and product size distribution. His theory and index were introduced in a widely cited 1952 journal article.. Bond called his theory the "third theory of comminution", counting those of Peter von Rittinger and Friedrich Kick as the first and second. This term and the terminology of "laws of comminution", as in "Rittinger's law", "Kick's law", and "Bond's law", are sometimes used in the field, along with those of subsequent researchers including Walker and Hukki. Whereas Rittinger's theory held that the work done in breaking ... [...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] |
Mill (grinding)
A mill is a device, often a structure, machine or home appliance, kitchen appliance, that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many process (engineering), processes. There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand or by animals (e.g., via a crank (mechanism), hand crank), working animal (e.g., horse mill), wind (windmill) or water (watermill). In modern era, they are usually powered by electricity. The grinding of solid materials occurs through mechanical forces that break up the structure by overcoming the interior bonding forces. After the grinding the state of the solid is changed: the grain size, the grain size disposition and the grain shape. Milling also refers to the process of breaking down, separating, sizing, or classifying aggregate material (e.g. mining ore). For instance rock crushing or grinding to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IsaMill
The IsaMill is an energy-efficient mineral industry grinding mill that was jointly developed in the 1990s by Mount Isa Mines Limited ("MIM", a subsidiary of MIM Holdings Limited and now part of the Glencore Xstrata group of companies) and Netzsch Feinmahltechnik ("Netzsch"), a German manufacturer of bead mills.C R Fountain, ‘Isasmelt and IsaMills—models of successful R&D,’ in: ''Young Leaders’ Conference, Kalgoorlie, Western Australia, 19–21 March 2002'' (The Australasian Institute of Mining and Metallurgy: Melbourne, 2002), 1–12. The IsaMill is primarily known for its ultrafine grinding applications in the mining industry, but is also being used as a more efficient means of coarse grinding.G S Anderson and B D Burford, "IsaMill—the crossover from ultrafine to coarse grinding," in: ''Metallurgical Plant Design and Operating Strategies (MetPlant 2006), 18–19 September 2006, Perth, Western Australia'' (The Australasian Institute of Mining and Metallurgy: Melbourne, 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Von Rittinger
Peter Ritter von Rittinger or Peter von Rittinger (see styling variants at ''Ritter'') (23 January 1811 Nový Jičín / Neutitschein – 7 December 1872 Vienna) was an Austrian pioneer of mineral processing. Life After completion of legal studies, von Rittinger studied in the mining department at the Mining and Forestry Academy in Schemnitz (Banská Štiavnica, Slovakia). After completing his studies in 1840, he immediately became a stamp mill inspector in the civil service. In this role, he led a number of improvements in mineral processing. In 1849, he was appointed the head of the Office to the Jáchymov district. That year also witnessed the invention of the continuous transverse shock outbreak. The introduction of this innovation in processing technology constituted a major advance. Continuous operation was made possible by the surge range. This separation process was based on differing specific gravities of minerals in the slurry, which in Rittinger's structure, along wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastication
Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding. The muscles of mastication move the jaws to bring the teeth into intermittent contact, repeatedly occluding and opening. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs. Increasing the number of chews per bite increases relevant gut hormones. Studies suggest that chewing may decrease self-reported hunger and food intake. Chewing gum has been around for many centuries; there is evidence that northern Europeans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crusher
A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, sand or rock dust. Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of the stone provided a bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammer Crusher
A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, sand or rock dust. Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of the stone provided a boost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
