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Alite
Alite is an impure form of tricalcium silicate, , sometimes formulated as ( in cement chemist notation), typically with 3-4% of substituent oxides. It is the major, and characteristic, phase in Portland cement. The name was given by Alfred Elis Törnebohm in 1897 to a crystal identified in microscopic investigation of Portland cement. Hatrurite is the name of a mineral that is substituted . Composition and structure The alite found in Portland cement differs in composition from simple tricalcium silicate. It is a solid solution and contains minor amounts of other oxides besides CaO and . A typical composition is: Based on this, the formula can be expressed as . In practice, the composition varies with the bulk composition of the clinker, subject to certain limits. Substitution of calcium ions or orthosilicate ions requires that electric charges be kept in balance. For instance, a limited number of orthosilicate () ions can be replaced with sulfate () ions, provided th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siliceous Limestone
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant families of materials, existing as a compound of several minerals and as a synthetic product. Examples include fused quartz, fumed silica, opal, and aerogels. It is used in structural materials, microelectronics, and as components in the food and pharmaceutical industries. All forms are white or colorless, although impure samples can be colored. Silicon dioxide is a common fundamental constituent of glass. Structure In the majority of silicon dioxides, the silicon atom shows Tetrahedral molecular geometry, tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricalcium Silicate
Alite is an impure form of tricalcium silicate, , sometimes formulated as ( in cement chemist notation), typically with 3-4% of substituent oxides. It is the major, and characteristic, phase in Portland cement. The name was given by Alfred Elis Törnebohm in 1897 to a crystal identified in microscopic investigation of Portland cement. Hatrurite is the name of a mineral that is substituted . Composition and structure The alite found in Portland cement differs in composition from simple tricalcium silicate. It is a solid solution and contains minor amounts of other oxides besides CaO and . A typical composition is: Based on this, the formula can be expressed as . In practice, the composition varies with the bulk composition of the clinker, subject to certain limits. Substitution of calcium ions or orthosilicate ions requires that electric charges be kept in balance. For instance, a limited number of orthosilicate () ions can be replaced with sulfate () ions, provided that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portland Cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar (masonry), mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th century by Joseph Aspdin, and is usually made from limestone. It is a fine powder (substance), powder, produced by heating limestone and clay minerals in a kiln to form Clinker (cement), clinker, and then #Cement grinding, grinding the clinker with the addition of several percent (often around 5%) gypsum. Several types of portland cement are available. The most common, historically called ordinary portland cement (OPC), is grey, but white portland cement is also available. The cement was so named by Joseph Aspdin, who obtained a patent for it in 1824, because, once hardened, it resembled the fine, pale limestone known as Portland stone, quarried from the windswept cliffs of the Isle of Portland in Dorset. Portland stone was p ... [...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, SiO2 (C2S in cement chemist notation). Etymology The name was given by Alfred Elis 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 Ca1.94Mg0.02Na0.01K0.03Fe0.02Al0.07Si0.90P0.01O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinker (cement)
image:LDClinkerScaled.jpg, 200px, Typical clinker nodules image:Hot Clinker 2.jpg, 200px, Hot clinker Cement clinker is a solid material produced in the manufacture of portland cement as an intermediary product. Clinker occurs as lumps or nodules, usually to in diameter. It is produced by sintering (fusing together without melting to the point of liquefaction) limestone and aluminosilicate materials such as clay during the cement kiln stage. Composition and preparation The Portland clinker essentially consists of four minerals: two calcium silicates, alite (Ca3SiO5) and belite (Ca2SiO4), along with tricalcium aluminate (Ca3Al2O6) and calcium aluminoferrite (Ca2(Al,Fe)2O5). These main mineral phases are produced by heating at high temperature clays and limestone. The major raw material for the clinker-making is usually limestone mixed with a second material containing clay as a source of alumino-silicate. An impure limestone containing clay or silicon dioxide (SiO2) can be used. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belgium
Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to the south, and the North Sea to the west. Belgium covers an area of and has a population of more than 11.8 million; its population density of ranks List of countries and dependencies by population density, 22nd in the world and Area and population of European countries, sixth in Europe. The capital and Metropolitan areas in Belgium, largest metropolitan region is City of Brussels, Brussels; other major cities are Antwerp, Ghent, Charleroi, Liège, Bruges, Namur, and Leuven. Belgium is a parliamentary system, parliamentary constitutional monarchy with a complex Federation, federal system structured on regional and linguistic grounds. The country is divided into three highly autonomous Communities, regions and language areas o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a precipitation (chemistry), chemical precipitate or a diagenesis, diagenetic replacement, as in petrified wood. Chert is typically composed of the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor, and which contains the silicon skeletal remains of diatoms, Dictyochales, silicoflagellates, and radiolarians. Precambrian cherts are notable for the presence of fossil cyanobacteria. In addition to Micropaleontology, microfossils, chert occasionally contains macrofossils. However, some chert is devoid of any fossils. Chert varies greatly in color, from white to black, but is most often found as gray, brown, grayish brown and light green to rusty redW.L. Roberts, T.J. Campbell, G.R. Rapp Jr., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portlandite
Portlandite is a hydroxide-bearing mineral typically included in the oxide mineral class. It is the naturally occurring form of calcium hydroxide (Ca(OH)2) and the calcium analogue of brucite (Mg(OH)2). Occurrence Portlandite occurs in a variety of environments. At the type location in Northern Ireland it occurs as an alteration of calc–silicate rocks by contact metamorphism of larnite– spurrite. It occurs as fumarole deposits in the Vesuvius area. In Jebel Awq, Oman, it occurs as precipitates from an alkaline spring emanating from ultramafic bedrock. In the Chelyabinsk coal basin of Russia it is produced by combustion of coal seams and similarly by spontaneous combustion of bitumen in the Hatrurim Formation of the Negev desert in Israel and the Maqarin area, Jordan. It also occurs in the manganese mining area of Kuruman, Cape Province, South Africa in the Kalahari Desert where it occurs as large crystals and masses. It occurs in association with afwillite, calcite, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfate
The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many are prepared from that acid. Spelling "Sulfate" is the spelling recommended by IUPAC, but "sulphate" was traditionally used in British English. Structure The sulfate anion consists of a central sulfur atom surrounded by four equivalent oxygen atoms in a tetrahedral arrangement. The symmetry of the isolated anion is the same as that of methane. The sulfur atom is in the +6 oxidation state while the four oxygen atoms are each in the −2 state. The sulfate ion carries an overall charge of −2 and it is the conjugate base of the bisulfate (or hydrogensulfate) ion, , which is in turn the conjugate base of , sulfuric acid. Organic sulfate esters, such as dimethyl sulfate, are covalent compounds and esters of sulfuric acid. The tetrahedral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tournai
Tournai ( , ; ; ; , sometimes Anglicisation (linguistics), anglicised in older sources as "Tournay") is a city and Municipalities in Belgium, municipality of Wallonia located in the Hainaut Province, Province of Hainaut, Belgium. It lies by road southwest of the centre of Brussels on the river Scheldt, and is part of Eurometropolis Lille–Kortrijk–Tournai, In 2022, the municipality of Tournai had an estimated population of 68,518 people. Tournai is one of the oldest cities in Belgium and has played an important role in the country's cultural history. It was the first capital of the Francia, Frankish Empire, with Clovis I being born here. Geography Tournai lies by road southwest of the centre of Brussels on the river Scheldt. Administratively, the town and municipality is part of the Hainaut Province, Province of Hainaut, in the Wallonia region of southwest Belgium. The municipality has an area of . Tournai has its own Arrondissements of Belgium, arrondissements, both ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tournaisian
The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from Ma to Ma. It is preceded by the Famennian (the uppermost stage of the Devonian) and is followed by the Viséan. In global stratigraphy, the Tournaisian contains two substages: the Hastarian (lower Tournaisian) and Ivorian (upper Tournaisian). These two substages were originally designated as European regional stages. Name and regional alternatives The Tournaisian was named after the Belgian city of Tournai. It was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1832. Like many Devonian and lower Carboniferous stages, the Tournaisian is a unit from West European regional stratigraphy that is now used in the official international time scale. The Tournaisian correlates with the regional North American Kinderhookian and lower Osagean stages and the Chinese Tan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
