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Slag Cement
Ground-granulated blast-furnace slag (GGBS or GGBFS) is obtained by quenching molten iron slag (a by-product of iron and steel-making) from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder. Ground-granulated blast furnace slag is a latent hydraulic binder forming calcium silicate hydrates (C-S-H) after contact with water. It is a strength-enhancing compound improving the durability of concrete. It is a component of metallurgic cement ( in the European norm ). Its main advantage is its slow release of hydration heat allowing to limit the temperature increase in massive concrete components and structures during cement setting and concrete curing, or to cast concrete during hot summer. Production and composition The chemical composition of a slag varies considerably depending on the composition of the raw materials in the iron production process. Silicate and aluminate impurities from the ore and coke are comb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slag
Slag is a by-product of smelting (pyrometallurgical) ores and used metals. Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-products of recovering non-ferrous materials like copper, nickel, zinc and phosphorus). Within these general categories, slags can be further categorized by their precursor and processing conditions (e.g., Blast furnace (BF) slags, air-cooled blast furnace (ACBF) slag, basic oxygen furnace (BOF) slag, and electric arc furnace (EAF) slag) . Due to the large demand for these materials, slag production has also significantly increased throughout the years despite recycling (most notably in the iron and steelmaking industries) and upcycling efforts. The World Steel Association (WSA) estimates that 600 kg of by-products (~90 wt% is slags) are generated per tonne of steel produced. Composition Slag is usually a mixture of metal oxides and sili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Singapore
Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, bordering the Strait of Malacca to the west, the Singapore Strait to the south, the South China Sea to the east, and the Straits of Johor to the north. The country's territory is composed of one main island, 63 satellite islands and islets, and one outlying islet; the combined area of these has increased by 25% since the country's independence as a result of extensive land reclamation projects. It has the third highest population density in the world. With a multicultural population and recognising the need to respect cultural identities of the major ethnic groups within the nation, Singapore has four official languages: English, Malay, Mandarin, and Tamil. English is the lingua franca and numerous public services are available only in Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pozzolan
Pozzolans are a broad class of Silicon_dioxide, siliceous and aluminium oxide, aluminous materials which, in themselves, possess little or no cementitious value but which will, in finely divided form and in the presence of water, react chemically with calcium hydroxide (Ca(OH)2) at ordinary temperature to form compounds possessing cementitious properties. The quantification of the capacity of a pozzolan to react with calcium hydroxide and water is given by measuring its pozzolanic activity. ''Pozzolana'' are naturally occurring pozzolans of volcanic origin. History Mixtures of Calcination, calcined lime and finely ground, active aluminosilicate materials were pioneered and developed as inorganic binders in the Ancient world. Architectural remains of the Minoan civilization on Crete have shown evidence of the combined use of Calcium hydroxide, slaked lime and additions of finely ground potsherds for waterproof Cement render, renderings in baths, cisterns and aqueducts. Evidence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oldhamite
Oldhamite is a calcium magnesium sulfide mineral with the chemical formula . Ferrous iron may also be present in the mineral resulting in the chemical formula . It is a pale to dark brown accessory mineral in meteorites. It crystallizes in the cubic crystal system, but typically occurs as Euhedral and anhedral, anhedral grains between other minerals. Discovery and occurrence It was first described in 1862 for an occurrence in the Bustee meteorite, Gorakhpur, Uttar Pradesh, India. It was named for Irish geologist Thomas Oldham (1816–1878), the Director of the Indian Geological Survey. It occurs as an interstitial mineral phase between silicate minerals in enstatite chondrite and achondrite meteorites. It occurs in association with enstatite, augite, niningerite, osbornite, troilite, gypsum and calcite. It has been reported from a variety of meteorite locations around the world including the Allan Hills 84001 meteorite of Antarctica. It has also been reported from a slag occurren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wollastonite
Wollastonite is a calcium inosilicate mineral ( Ca Si O3) that may contain small amounts of iron, magnesium, and manganese substituting for calcium. It is usually white. It forms when impure limestone or dolomite is subjected to high temperature and pressure, which sometimes occurs in the presence of silica-bearing fluids as in skarns or in contact with metamorphic rocks. Associated minerals include garnets, vesuvianite, diopside, tremolite, epidote, plagioclase feldspar, pyroxene and calcite. It is named after the English chemist and mineralogist William Hyde Wollaston (1766–1828). Despite its chemical similarity to the compositional spectrum of the pyroxene group of minerals—where magnesium (Mg) and iron (Fe) substitution for calcium ends with diopside and hedenbergite respectively—it is structurally very different, with a third tetrahedron in the linked chain (as opposed to two in the pyroxenes). Production trends Estimated world production of crude wollastonite ore was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monticellite
Monticellite and kirschsteinite (commonly also spelled kirschteinite Klein and Hurlbut ''Manual of Mineralogy'' 20th ed., p. 373) are gray silicate minerals of the olivine group with compositions Ca Mg Si O4 and Ca FeSiO4, respectively. Most monticellites have the pure magnesium end-member composition but rare ferroan monticellites and magnesio-kirschsteinite are found with between 30 and 75 mol.% of the iron end member. Pure kirschsteinite is only found in synthetic systems. Monticellite is named after Teodoro Monticelli Italian mineralogist (1759–1845). Kirschsteinite is named after Egon Kirschstein, German geologist. Like other members of the group monticellite and kirschsteinite have orthorhombic unit cells (space group ''Pbnm'') shown in Figure 1. Iron and magnesium ions are located on the M1 inversion sites and calcium ions occupy the M2 site on mirror planes. The unit cell is somewhat larger than for the calcium free olivines forsterite and fayalite Fayalite ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belite
Belite is an industrial mineral important in Portland cement manufacture. Its main constituent is dicalcium silicate, Ca2SiO4, sometimes formulated as 2 CaO · SiO2 (C2S in cement chemist notation). Etymology The name was given by Törnebohm in 1897 to a crystal identified in microscopic investigation of Portland cement. Belite is a name in common use in the cement industry, but is not a recognised mineral name. It occurs naturally as the mineral larnite, the name being derived from Larne, Northern Ireland, the closest town to Scawt Hill where it was discovered. Composition and structure The belite found in Portland cement differs in composition from pure dicalcium silicate. It is a solid solution and contains minor amounts of other oxides besides CaO and SiO2. A typical composition:Taylor H.F.W. (1990), ''Cement Chemistry'', Academic Press, 1990, , pp. 10-11. Based on this, the formula can be expressed as Ca1.94Mg0.02Na0.01K0.03Fe0.02Al0.07Si0.90P0.01O3.93. In practic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. Despite bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Hydration
In chemistry, mineral hydration is an inorganic chemical reaction which adds water to the crystal structure of a mineral, usually creating a new mineral, usually called a ''hydrate''. In geological terms, the process of mineral hydration is known as ''retrograde alteration'' and is a process occurring in retrograde metamorphism. It commonly accompanies metasomatism and is often a feature of wall rock alteration around ore bodies. Hydration of minerals occurs generally in concert with hydrothermal circulation which may be driven by tectonic or igneous activity. Processes There are two main ways in which minerals hydrate. One is conversion of an oxide to a double hydroxide, as with the hydration of calcium oxide—CaO—to calcium hydroxide—Ca(OH)2, the other is with the incorporation of water molecules directly into the crystalline structure of a new mineral. The later process is exhibited in the hydration of feldspars to clay minerals, garnet to chlorite, or kyanite to m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressive Strength
In mechanics, compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size (as opposed to tensile strength which withstands loads tending to elongate). In other words, compressive strength resists compression (being pushed together), whereas tensile strength resists tension (being pulled apart). In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently. Some materials fracture at their compressive strength limit; others deform irreversibly, so a given amount of deformation may be considered as the limit for compressive load. Compressive strength is a key value for design of structures. Compressive strength is often measured on a universal testing machine. Measurements of compressive strength are affected by the specific test method and conditions of measurement. Compressive strengths are usually reported in relationship to a specific tec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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