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Perlite
Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. It is an industrial mineral, suitable "as ceramic flux to lower the sintering temperature", and a commercial product useful for its low density after processing. Properties Perlite softens when it reaches temperatures of . Water trapped in the structure of the material vaporises and escapes, and this causes the expansion of the material to 7–16 times its original volume. The expanded material is a brilliant white, due to the reflectivity of the trapped bubbles. Unexpanded ("raw") perlite has a bulk density around 1100 kg/m3 (1.1 g/cm3), while typical expanded perlite has a bulk density of about 30–150 kg/m3 (0.03–0.150 g/cm3). Typical analysis *70–75% silicon dioxide: SiO2 *12–15% aluminium oxide: Al2O3 *3–4% sodium oxide: Na2O *3–5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntactic Foam
Syntactic foams are composite materials synthesized by filling a metal, polymer, or ceramic matrix with hollow spheres called microballoons or cenospheres or non-hollow spheres (e.g. perlite). In this context, "syntactic" means "put together." The presence of hollow particles results in lower density, higher specific strength (strength divided by density), lower coefficient of thermal expansion, and, in some cases, radar or sonar transparency. A manufacturing method for low density syntactic foams is based on the principle of buoyancy. The term was originally coined by the Bakelite Company, in 1955, for their lightweight composites made of hollow phenolic microspheres bonded to a matrix of phenolic, epoxy, or polyester. Tailorability is one of the biggest advantages of these materials. The matrix material can be selected from almost any metal, polymer, or ceramic. Microballoons are available in a variety of sizes and materials, including glass microspheres, cenospheres, carbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obsidian
Obsidian () is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolite, rhyolitic lava flows known as obsidian flows. These flows have a high content of silicon dioxide, silica, granting them a high viscosity. The high viscosity inhibits atomic diffusion, diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava. Obsidian is hard, Brittleness, brittle, and amorphous; it therefore Fracture (mineralogy)#Conchoidal fracture, fractures with sharp edges. In the past, it was used to manufacture cutting and piercing tools, and it has been used experimentally as surgic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Insulation
Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials. Heat flow is an inevitable consequence of contact between objects of different temperature. Thermal insulation provides a region of insulation in which thermal conduction is reduced, creating a thermal break or thermal barrier, or thermal radiation is reflected rather than absorbed by the lower-temperature body. The insulating capability of a material is measured as the inverse of thermal conductivity (k). Low thermal conductivity is equivalent to high insulating capability ( resistance value). In thermal engineering, other important properties of insulating materials are product density (ρ) and specific heat capacity (c). Definition T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatomaceous Earth
Diatomaceous earth (), diatomite (), or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 μm to less than 1 mm, but typically 10 to 200 μm. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% alumina (attributed mostly to clay minerals), and 0.5–2% iron oxide. Diatomaceous earth consists of the fossilized remains of diatoms, a type of hard-shelled microalgae. It is used as a filtration aid, mild abrasive in products including metal polishes and toothpaste, mechanical insecticide, absorbent for liquids, matting agent for coatings, reinforcing filler in plastics and rubber, anti-block in plastic films, porous support for c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Glass
Volcanic glass is the amorphous (uncrystallized) product of rapidly cooling magma. Like all types of glass, it is a state of matter intermediate between the closely packed, highly ordered array of a crystal and the highly disordered array of liquid. Volcanic glass may refer to the interstitial material, or matrix, in an aphanitic (fine-grained) volcanic rock, or to any of several types of vitreous igneous rocks. Origin Volcanic glass is formed when magma is rapidly cooled. Magma rapidly cooled to below its normal crystallization temperature becomes a supercooled liquid, and, with further rapid cooling, this becomes an amorphous solid. The change from supercooled liquid to glass occurs at a temperature called the glass transition temperature, which depends on both cooling rate and the amount of water dissolved in the magma. Magma rich in silica and poor in dissolved water is most easily cooled rapidly enough to form volcanic glass. As a result, rhyolite magmas, which are high in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filtration
Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filter medium are described as ''oversize'' and the fluid that passes through is called the ''filtrate''. Oversize particles may form a filter cake on top of the filter and may also block the filter lattice, preventing the fluid phase from crossing the filter, known as ''blinding''. The size of the largest particles that can successfully pass through a filter is called the effective ''pore size'' of that filter. The separation of solid and fluid is imperfect; solids will be contaminated with some fluid and filtrate will contain fine particles (depending on the pore size, filter thickness and biological activity). Filtration occurs both in nature and in engineered systems; there are biological, geological, and industrial forms. Filtration is als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Minerals
Industrial resources (minerals) are geological materials which are mined for their commercial value, which are not fuel (fuel minerals or mineral fuels) and are not sources of metals (metallic minerals) but are used in the industries based on their physical and/or chemical properties. They are used in their natural state or after beneficiation either as raw materials or as additives in a wide range of applications. Examples and applications Typical examples of industrial rocks and minerals are limestone, clays, sand, gravel, diatomite, kaolin, bentonite, silica, barite, gypsum, and talc. Some examples of applications for industrial minerals are construction, ceramics, paints, electronics, filtration, plastics, glass, detergents and paper. In some cases, even organic materials (peat) and industrial products or by-products (cement, slag, silica fume) are categorized under industrial minerals, as well as metallic compounds mainly utilized in non-metallic form (as an example most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceramics (art)
Ceramic art is art made from ceramic materials, including clay. It may take forms including artistic pottery, including tableware, tiles, figurines and other sculpture. As one of the plastic arts, ceramic art is one of the visual arts. While some ceramics are considered fine art, such as pottery or sculpture, most are considered to be decorative, industrial or applied art objects. Ceramics may also be considered artefacts in archaeology. Ceramic art can be made by one person or by a group of people. In a pottery or ceramic factory, a group of people design, manufacture and decorate the art ware. Products from a pottery are sometimes referred to as "art pottery". In a one-person pottery studio, ceramists or potters produce studio pottery. The word "ceramics" comes from the Greek ''keramikos'' (κεραμεικός), meaning "pottery", which in turn comes from ''keramos'' (κέραμος) meaning "potter's clay". Most traditional ceramic products were made from clay ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plaster
Plaster is a building material used for the protective or decorative coating of walls and ceilings and for Molding (decorative), moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. Another imprecise term used for the material is stucco, which is also often used for plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces. The most common types of plaster mainly contain either gypsum, lime plaster, lime, or cement plaster, cement,Franz Wirsching "Calcium Sulfate" in Ullmann's Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH, Weinheim. but all work in a similar way. The plaster is manufactured as a dry powder and is mixed with water to form a stiff but workable paste immediately before it is applied to the surface. The reaction with water liberates heat through crystallization and the hydrated plaster then ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Materials
A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Typical engineered composite materials include: * Reinforced concrete and masonry *Composite wood such as plywood *Reinforced plastics, such as fibre-reinforced polymer or fiberglass *Ceramic matrix composites ( composite ceramic and metal matrices) *Metal matrix composites *and other advanced composite materials There are various reasons where new material can be favoured. Typical examples include materials which are less expensive, lighter, stronger or more durable when compared with com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mortar (masonry)
Mortar is a workable paste which hardens to bind building blocks such as stones, bricks, and concrete masonry units, to fill and seal the irregular gaps between them, spread the weight of them evenly, and sometimes to add decorative colors or patterns to masonry walls. In its broadest sense, mortar includes pitch, asphalt, and soft mud or clay, as those used between mud bricks, as well as cement mortar. The word "mortar" comes from Old French ''mortier'', "builder's mortar, plaster; bowl for mixing." (13c.). Cement mortar becomes hard when it cures, resulting in a rigid aggregate structure; however, the mortar functions as a weaker component than the building blocks and serves as the sacrificial element in the masonry, because mortar is easier and less expensive to repair than the building blocks. Bricklayers typically make mortars using a mixture of sand, a binder, and water. The most common binder since the early 20th century is Portland cement, but the ancient binder lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundry
A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron. However, other metals, such as bronze, brass, steel, magnesium, and zinc, are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed. Foundries are one of the largest contributors to the manufacturing recycling movement, melting and recasting millions of tons of scrap metal every year to create new durable goods. Moreover, many foundries use sand in their molding process. These foundries often use, recondition, and reuse sand, which is another form of recycling. Process In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
