Aluminiumoksid Alumina

Aluminium oxide (Alumina) forms the core material for many industrial ceramics. It has hard, brittle properties with a high melting point, low electrical conductivity and exceptional thermal stability properties.

Corundum is made up primarily of stable rhombohedral crystal forms of alumina (a-Al2O3) that has a stable crystalline form called corundum-alumina, with trace amounts of chromium providing its characteristic red hue while iron and titanium contribute blue sapphire hues for blue sapphire gem quality varieties such as rubies.


Aluminium oxide alumina is an integral material in the production of metals and used to produce aluminium metal alloys. Due to its high melting point and excellent thermal resistance properties, kilns, ceramics and furnace linings often use it. Aluminium oxide alumina also plays an essential part in producing civil and military armor due to its strength, lightweight qualities and ballistic properties.

Aluminium oxide (alumina) is produced through refining bauxite ore, in an alumina refinery. This process usually occurs in large rectangular buildings spanning an estimated one kilometer long that contain hundreds of reduction cells connected to power via large cables; when combined together these produce corundum or aluminium oxide as its final product.

Corundum is the most widespread form of aluminium oxide and second only to diamond in terms of hardness. Gem-quality forms of Corundum include rubies and sapphires which owe their rich colors to trace impurities such as chromium, iron and titanium atoms. Corundum serves as the main ingredient in cutting tools as well as numerous abrasives used on its surfaces; other applications for Corundum also exist.

Refineries employ aluminium oxide alumina as the base for industrial refractories used in complex thermochemical and thermomechanical processes, such as autothermal reforming for hydrocarbon conversion into synthesis gas (synthesis fuel). High purity alumina ceramics provide superior chemical inertness required for successful performance of such applications.

Alumina is often employed as a catalyst in refineries to facilitate reactions that take place there, including those related to elemental sulfur production via the Claus process or for alcohols being transformed into alkenes.

Alumina is often added to cement and concrete products to increase their tensile strength, durability and corrosion resistance as well as their environmental factors resistance. Alumina can also be added to adhesives and sealants in order to increase bonding strength, resilience and resistance against chemicals; additionally it’s widely used in manufacturing dental implants and prosthetic devices.


Aluminum oxide (also known by its chemical formula Al2O3) is an all-purpose compound with numerous applications. It serves as a key raw material in producing metallic aluminum as well as industrial ceramics; additionally it can also occur naturally as precious gems such as rubies and sapphires.

Corundum is an aluminum oxide with an intricate hexagonal close-packed structure and abundant oxygen ions; two-thirds of which fill available octahedral interstices while remaining space is filled by Al3+ ions for binding with other atoms to form a neutral structure without charge balancing cations required for its stabilization.

Natural corundum can be found in igneous, metamorphic and sedimentary rocks. Its primary source is bauxite which yields high-purity alumina powders (>99.9% Al2O3); corundum can be extracted using the Bayer process from this source material; major deposits exist in Australia, Brazil India Myanmar (Burma).

Pure corundum is also widely used as an abrasive material in industrial settings and beyond, particularly as part of manufacturing processes for high-purity alumina. Due to its hard and durable surface, pure corundum often incorporates small amounts of carbon, silicon dioxide and manganese oxide for added wear resistance.

Corundum can also be utilized as a catalyst. Absorbing water and other polar molecules allows it to be used in adsorption chromatography; additionally, its catalytic properties enable it to remove sulfur from hydrogen sulfide, dehydrate alcohols, and isomerize olefins.

Corundum crystal structures can vary considerably due to impurities present within its composition, including elemental substituents that contribute different colors. Rubies and sapphires owe their colors to trace amounts of Fe2+ and chromium ions found within them, respectively.

Corundum is an extremely resilient material that can be made into various shapes and sizes depending on its application. Machined for abrasive products, as well as applications requiring high temperature resistance and good electrical insulation properties. Through bonding and forming techniques it can also produce fine-grained alumina material with superior wear resistance properties that possesses excellent wear resistance characteristics.

Flame Retardants

Aluminum oxide can be found in numerous applications as a flame retardant and is also often employed as an insulator on printed circuit boards (PCBs) used for electronic equipment. Aluminium oxide’s ability to block electric current flows between components provides safety and isolation of electrical systems while its insulating properties reduce short circuiting risks and product damage risks.

flame retardant properties stem from its ability to absorb and release heat slowly, thus helping products avoid becoming flammable. Its usage as an organic and halogenated flame retardant replacement is gradually being phased out due to their negative environmental impact.

Aluminium Trihydroxide, more commonly referred to as ATH, is an efficient aluminium hydroxide flame retardant used widely today. It offers an effective alternative to halogenated chemicals which emit toxic fumes when broken down, as well as environmental issues they create upon decomposition. Metal hydroxides compounds are non-toxic and break down into water and inert oxides when heated; furthermore they’re more eco-friendly than organo-bromine compounds such as Polybrominated Biphenyl Ethers (PBDE). These have become the mainstay of fire retardant chemicals over the past several years.

Aluminium oxide alumina undergoes numerous treatments during its production to enhance its flame retardant capabilities. Silanes are applied to its surface to screen out coarse particles and ensure a uniform particle size distribution; this helps improve dispersion with various materials and can aid in dispersion processes. Finally, thermal shock treatment further increases flame retardancy capabilities.

In addition to flame retardant properties, ATH displays outstanding oxidative stability that can extend the lifespan of polymers and other products that come into contact with it. Furthermore, its resistance to migration in moderate heat or humidity ageing conditions and high surface area helps improve mechanical properties when mixed into polymers.


Alumina is an inert material used in making glass or coating metals to insulate them from heat, as well as being melted and cast into shapes. Aluminium oxide can also serve as thermal insulator in furnaces and spark plugs, with its high melting point, low specific gravity, refractory properties enabling ceramic production.

Hard and bio-inert, ceramic is the material of choice for bearings in hip replacements, dental implants and tissue reinforcements. Furthermore, ceramic is found in medical devices like artificial knees and stents as well as lab equipment like crucibles furnaces and other tools.

Corundum is an aluminium oxide alumina form found in gem-quality rubies and sapphires with deep colors, such as rubies and sapphires from Brazil and Sri Lanka. However, their colors come not from pure aluminium oxide but instead contain trace impurities such as iron or titanium which give their colors their signature hues. Due to its hardness it can also be formed into cutting tool abrasives for cutting tools.

As soon as alumina dissolves in water, hydroxyl groups form that interact with proteins to increase its wettability compared to various metallic alloys and make alumina an ideal candidate as a corrosion protectant coating material. Alumina also frequently used as clay admixture in kilns in order to produce hard glazes for use as ceramic decoration and anodization treatments on aluminium components.

Aluminum oxide is used in the production of abrasives, ceramics and some plastics. Additionally, it can be melted and formed into shape for use as furnace insulation or metal castings or sheaths for thermocouples (temperature measuring instruments). These instruments work through using the Seebeck effect: two metal wires of differing temperatures are joined at one end with soldered joints before their other ends are attached to a piece of ceramic or refractory that prevents heat loss from the colder metal at the hotter end thereby creating an electric potential difference that can be measured electronically using an electronic device.

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