| Aluminium oxide | |
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| Identifiers | |
| CAS number | [1344-28-1] |
| Properties | |
| Molar mass | 101. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 96 g/mol |
| Density | 3. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 97 g cm−3, solid |
| Melting point |
2054 °C |
| Boiling point |
2980 °C [1] |
| Solubility in water | insoluble |
| Structure | |
| Coordination geometry |
octahedral |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−1675. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. The term coordination geometry is used in a number of related fields of chemistry and solid state chemistry/physics An octahedron (plural octahedra is a Polyhedron with eight faces The standard enthalpy of formation or "standard heat of formation" of a compound is the change of Enthalpy that accompanies the formation of 1 mole of a 7 kJ mol−1 |
| Standard molar entropy S |
50. In Chemistry, the standard molar entropy is the Entropy content of one mole of substance under standard conditions (not standard temperature and pressure 92 J mol−1 K−1 |
| Hazards | |
| MSDS | External MSDS |
| EU classification | Not listed. A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance This page provides supplementary chemical data on Aluminium oxide. Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling |
| Flash point | non-flammable |
| Related compounds | |
| Other anions | aluminium hydroxide |
| Other cations | boron trioxide gallium oxide indium oxide thallium oxide |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Aluminium hydroxide, Al(OH3 is the most stable form of Aluminium in normal conditions An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Boron oxide is one of the oxides of Boron. It is white glassy and solid also known as diboron trioxide, formula B2O3 Indium(III oxide ( In2[[Oxygen O3]] is a Chemical compound, an Amphoteric Oxide of Indium. Thallium oxide is the general name of several Oxides of Thallium. This page provides supplementary chemical data on Aluminium oxide. This page provides supplementary chemical data on Aluminium oxide. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium Measurement The relative static permittivity εr can be measured for static Electric fields as follows first the Capacitance of a test |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Aluminium oxide is an amphoteric oxide of aluminium with the chemical formula Al2O3. This page provides supplementary chemical data on Aluminium oxide. This page provides supplementary chemical data on Aluminium oxide. Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry ( UV/ VIS) involves the Spectroscopy of Photons in the UV-visible Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique which exploits the magnetic properties of certain nuclei Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly WikipediaNaming A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes WikipediaNaming Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the It is also commonly referred to as alumina or aloxite[2] in the mining, ceramic and materials science communities. Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body The word ceramic is derived from the Greek word κεραμικός ( keramikos) Materials Science or Materials Engineering is an interdisciplinary field involving the properties of matter and its applications to various areas of Science and It is produced by the Bayer process from bauxite. The Bayer process is the principal industrial means of refining Bauxite to produce Alumina. Bauxite is the most important Aluminium Ore. It consists largely of the minerals Gibbsite Al(OH3 Boehmite γ-AlO(OH and Its most significant use is in the production of aluminium metal, although it is also used as an abrasive due to its hardness and as a refractory material due to its high melting point. WikipediaNaming A refractory is a material that retains its strength at high Temperatures ASTM C71 defines refractories as "non-metallic materials having those chemical and physical [3]
Contents |
Natural occurrence
Corundum is the naturally occurring crystalline form of aluminium oxide. Corundum (from Tamil kurundam குருந்தம் or kuruvindam குருவிந்தம் is a Crystalline form of In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating Rubies and sapphires are gem-quality forms of corundum with their characteristic colors due to trace impurities in the corundum structure. A Ruby is a pink to blood-red Gemstone, a variety of the Mineral Corundum ( Aluminium oxide) Sapphire (antique greek hyacinthos refers to gem varieties of the mineral Corundum, an Aluminium oxide (Al2O3 when it is a color other than
Properties
Aluminium oxide is an electrical insulator but has a relatively high thermal conductivity (40 W/m K). An insulator, also called a Dielectric, is a material that resists the flow of Electric current. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. In its most commonly occurring crystalline form, called corundum or α-aluminium oxide, its hardness makes it suitable for use as an abrasive and as a component in cutting tools. Corundum (from Tamil kurundam குருந்தம் or kuruvindam குருவிந்தம் is a Crystalline form of An abrasive is a material often a Mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away In the context of Metalworking, a cutting tool, is any tool that is used to remove metal from the workpiece by means of shear deformation [3]
Aluminium oxide is responsible for metallic aluminium's resistance to weathering. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere. Metallic aluminium is very reactive with atmospheric oxygen, and a thin passivation layer of alumina quickly forms on any exposed aluminium surface. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Passivation is the process of making a material "passive" in relation to another material prior to using the materials together This layer protects the metal from further oxidation. The thickness and properties of this oxide layer can be enhanced using a process called anodising. Anodizing, or anodising, is an electrolytic Passivation process used to increase the thickness of the natural Oxide layer on the surface of metal A number of alloys, such as aluminium bronzes, exploit this property by including a proportion of aluminium in the alloy to enhance corrosion resistance. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Aluminium bronze is a type of Bronze in which Aluminium is the main Alloying Metal added to Copper. The alumina generated by anodising is typically amorphous, but discharge assisted oxidation processes such as plasma electrolytic oxidation result in a significant proportion of crystalline alumina in the coating, enhancing its hardness. An amorphous solid is a Solid in which there is no Long-range order of the positions of the Atoms (Solids in which there is long-range atomic order are Plasma electrolytic oxidation (PEO or microarc oxidation (MAO is an electrochemical Surface treatment process for generating Oxide Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force
Aluminium oxide was taken off the United States Environmental Protection Agency's chemicals lists in 1988. Year 1988 ( MCMLXXXVIII) was a Leap year starting on Friday (link displays 1988 Gregorian calendar) Aluminium oxide is on EPA's TRI list if it is a fibrous form.
Crystal structure
The most common form of crystalline alumina, α-aluminium oxide, is known as corundum. Corundum (from Tamil kurundam குருந்தம் or kuruvindam குருவிந்தம் is a Crystalline form of Corundum has a trigonal Bravais lattice with a space group of R-3c (number 167 in the International Tables). In Crystallography, the rhombohedral (or trigonal) Crystal system is one of the seven lattice point groups named after the two-dimensional Each unit cell contains six formula units of aluminum oxide. The oxygen ions nearly form a hexagonal close-packed structure with aluminium ions filling two-thirds of the octahedral interstices.
Production
Aluminium oxide, also known as alumina, is the main component of bauxite, the principal ore of aluminium. An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element Bauxite is the most important Aluminium Ore. It consists largely of the minerals Gibbsite Al(OH3 Boehmite γ-AlO(OH and An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining WikipediaNaming The largest manufacturers in the world of alumina are Alcoa, Alcan and Rusal. Manufacturing (from Latin manu factura, "making by hand" is the use of tools and labor to make things for use or sale Alcoa Inc ( is the world's third largest producer of Aluminum, behind Rio Tinto Alcan and Rusal. United Company Rusal (Российский алюминий is the world's largest Aluminium company Companies which specialise in the production of speciality aluminium oxides and aluminium hydroxides include Alcan and Almatis. The bauxite ore is made up of impure Al2O3, Fe2O3, and SiO2. Bauxite is purified by the Bayer process:
- Al2O3 + 3 H2O + 2 NaOH → 2NaAl(OH)4
The Fe2O3 does not dissolve in the base. The Bayer process is the principal industrial means of refining Bauxite to produce Alumina. The SiO2 dissolves as silicate Si(OH)62-. Upon filtering, Fe2O3 is removed. When the Bayer liquor is cooled, Al(OH)3 precipitates, leaving the silicates in solution. The mixture is then calcined (heated strongly) to give aluminium oxide:[3]
2Al(OH)3 + heat → Al2O3 + 3H2O
The formed Al2O3 is alumina. Calcination (also referred to as calcining) is a thermal treatment process applied to ores and other solid materials in order to bring about a Thermal decomposition
Uses
Annual world production of alumina is approximately 45 million tonnes, over 90% of which is used in the manufacture of aluminium metal. This article is about the tonne or metric ton For other tons see Ton. [3]. The major uses of speciality aluminium oxides are in refractories, ceramics, polishing and abrasive applications. Large tonnages are also used in the manufacture of zeolites, coating titania pigments and as a fire retardant/smoke suppressant. Zeolites (Greek zein, "to boil" lithos, "a stone" are hydrated Aluminosilicate Minerals and have a micro-porous structure
In lighting and photography, alumina is a medium for chromatography, available in basic (pH 9. Chromatography (from Greek χρώμα chroma, color and γραφειν"graphein" to write is the collective term for a family of Laboratory In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and pH is the measure of the acidity or alkalinity of a Solution. 5), acidic (pH 4. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are 5 when in water) and neutral formulations. In 1961, GE developed "Lucalox", a transparent alumina used in sodium vapor lamps. A sodium vapor lamp is a Gas discharge lamp which uses Sodium in an excited state to produce Light A sodium vapor lamp is a Gas discharge lamp which uses Sodium in an excited state to produce Light Aluminium oxide is also used in preparation of coating suspensions in compact fluorescent lamps.
Health and medical applications include it as a material in hip replacements,[3] in water filters (derived water treatment chemicals such as aluminium sulfate, aluminium chlorohydrate and sodium aluminate, are one of the few methods available to filter water-soluble fluorides out of water), and even in toothpaste formulations. Hip replacement, also hip Arthroplasty, is a surgical procedure in which the Hip joint is replaced by a prosthetic implant. Aluminium sulfate, written as Al 2( S[[Oxygen O4]]3 or Al 2 O12[[Sulfur S]]3 Aluminium chlorohydrate is a group of Salts having the general formula Al n Cl (3n-m( OH)m Sodium aluminate is an important commercial Inorganic chemical
Aluminium oxide is also used for its strength. Most pre-finished wood flooring now uses aluminium oxide as a hard protective coating. Wood finishing refers to the process of embellishing and/or protecting the surface A floor is the walking surface of a room or vehicle Floors vary from simple dirt in a cave to many-layered surfaces using modern technology Coating is a Covering that is applied to an object The aim of applying coatings is to improve surface properties of a bulk material usually referred to as a substrate In 2004, 3M developed a technique for making a ceramic composed of aluminium oxide and rare earth elements to produce a strong glass called transparent alumina. "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " 3M Company ( formerly Minnesota Mining and Manufacturing Company until 2002 is an American multinational conglomerate corporation with a worldwide The word ceramic is derived from the Greek word κεραμικός ( keramikos) Rare earth elements and rare earth metals are according to IUPAC, the collection of seventeen Chemical elements in the Periodic table, namely Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many Transparent alumina is a transparent form of Aluminium oxide, Al2O3 Alumina can be grown as a coating on aluminium by anodising or by plasma electrolytic oxidation (see the "Properties" section, above). Anodizing, or anodising, is an electrolytic Passivation process used to increase the thickness of the natural Oxide layer on the surface of metal Plasma electrolytic oxidation (PEO or microarc oxidation (MAO is an electrochemical Surface treatment process for generating Oxide Both its strength and abrasive characteristics are due to aluminium oxide's great hardness (position 9 on the Mohs scale of mineral hardness). Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material
It is widely used as a coarse or fine abrasive, including as a much less expensive substitute for industrial diamond. An abrasive is a material often a Mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in Many types of sandpaper use aluminium oxide crystals. Abrasive Paper is a form of Paper where an Abrasive material has been fixed to its surface In addition, its low heat retention and low specific heat make it widely used in grinding operations, particularly cutoff tools. Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity Metalworking is craft and practice of working with Metals to create individual parts assemblies or large scale structures As the powdery abrasive mineral aloxite, it is a major component, along with silica, of the cue tip "chalk" used in billiards. The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide A cue stick (or simply cue, or more specifically pool cue, snooker cue, or billiards cue) is an item of sporting equipment essential to the (See William A. Spinks, cue chalk co-inventor, for more information. William Alexander Spinks Jr (1865&ndash1933 known professionally as William A ) Aluminium oxide powder is used in some CD/DVD polishing and scratch-repair kits. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is Polishing is the process of creating a smooth and shiny surface by using rubbing or a chemical action leaving a surface with significant Specular reflection and minimal Its polishing qualities are also behind its use in toothpaste.
Aluminium oxide is widely used in the fabrication of superconducting devices, particularly single electron transistors and superconducting quantum interference devices (SQUID), where it is used to form highly resistive quantum tunnelling barriers. Superconductivity is a phenomenon occurring in certain Materials generally at very low Temperatures characterized by exactly zero electrical resistance In physics a Coulomb blockade, named after Charles-Augustin de Coulomb, is the increased resistance at small bias voltages of an electronic device comprising Squid are marine Cephalopods of the order Teuthida, which comprises around 300 species In Quantum mechanics, quantum tunnelling is a nanoscopic phenomenon in which a particle violates the principles of Classical mechanics by penetrating a
Aluminium oxide is considered a Welsbach material. It has been suggested that this chemical could be sprayed into the upper atmosphere to reflex sunlight and thus lower the global temperature. .
See also
References
- ^ Mallinckrodt Baker, MSDS. The Bayer process is the principal industrial means of refining Bauxite to produce Alumina. This is a list of Alumina refineries in the world The list is incomplete and missing some data Transparent aluminum (or aluminium) is a Fictional substance from the Star Trek Science fiction franchise Aluminum Oxide: Material Safety Data Sheet (A28440).
- ^ "Aloxite", ChemIndustry. com database, retrieved 24 February 2007
- ^ a b c d e Alumina (Aluminium Oxide) – The Different Types of Commercially Available Grades. Events 303 - Galerius, Roman Emperor, publishes his edict that begins the persecution of Christians in his portion of the Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. The A to Z of Materials. Retrieved on 2007-10-27. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 312 - Constantine the Great is said to have received his famous Vision of the Cross.
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