ALUMINIUM TRIHYDRATE

Aluminium trihydrate is found in nature as the mineral gibbsite (also known as hydrargillite) and Aluminium trihydrate three much rarer polymorphs: bayerite, doyleite, and nordstrandite.

Aluminium trihydrate is amphoteric, i.e., Aluminium trihydrate has both basic and acidic properties.

Aluminium trihydrate is a halogen-free, environmentally friendly flame retardant and smoke suppressant filler for plastics and rubber.

CAS Number: 21645-51-2

EC Number: 244-492-7

Chemical Formula: Al(OH)3

Molar Mass: 78.003 g·mol−1

Synonyms: Aluminium trihydrate, Aluminum, trihydrate, DTXSID20421935, MXRIRQGCELJRSN-UHFFFAOYSA-N, aluminum;trihydroxide, Dried aluminum hydroxide gel, Aluminium hydroxide gel, dried, aluminium trihydroxide, aluminum hyroxide, Hydroxyde d’ aluminium, Dried aluminium hydroxide, Aluminium hydroxide, dried, Aluminum hydroxide gel, dried, CHEMBL1200706, DTXSID2036405, NIOSH/BD0708000, Di-mu-hydroxytetrahydroxydialuminum, AF-260, AKOS015904617, Aluminum, di-mu-hydroxytetrahydroxydi-, DB06723, BD07080000, Aluminium trihydrate [ACD/IUPAC Name], Aluminium, trihydrate [French] [ACD/IUPAC Name], Aluminiumtrihydrat [German] [ACD/IUPAC Name], 106152-09-4 [RN], 12252-70-9 [RN], 128083-27-2 [RN], 1302-29-0 [RN], 13783-16-9 [RN], 14762-49-3 [RN], 151393-94-1 [RN], 159704-77-5 [RN], 21645-51-2 [RN], 51330-22-4 [RN], 8012-63-3 [RN], 8064-00-4 [RN], AC 714KC, AKP-DA, Al(OH)3, Alcoa A 325, Alcoa AS 301, Alcoa C 30BF, Alcoa C 31, Alcoa C 33, Alcoa C 330, Alcoa C 331, Alcoa C 333, Alcoa C 385, Alcoa H 65, Alhydrogel [Wiki], Alolt 8, ALterna GEL [Trade name], ALternaGEL, Alu-Cap, Alugel, Alugelibye, Alumigel, Alumina trihydrate, Aluminic acid (H3AlO3), Aluminium hydroxide [Wiki], aluminium(3+) hydroxide, aluminium(III) hydroxide, Aluminiumhydroxid, ALUMINUM HYDROXIDE [USP], Aluminum hydroxide (Al(OH)3), Aluminum Hydroxide Gel, Aluminum hydroxide, dried [JAN], Aluminum oxide trihydrate, Aluminum trihydroxide, Aluminum(III) hydroxide, Alusal, Amberol ST 140F, Amorphous alumina, Amphogel, Amphojel, Antipollon HT, Apyral, Apyral 120, Apyral 120VAW, Apyral 15, Apyral 2, Apyral 24, Apyral 25, Apyral 4, Apyral 40, Apyral 60, Apyral 8, Apyral 90, Apyral B, Arthritis Pain Formula Maximum Strength, Ascriptin, BACO AF 260, Boehmite, British aluminum AF 260, C 31C, C 31F, C 4D, C-31-F, Calcitrel, Calmogastrin, Camalox, Dialume [Trade name], Di-Gel Liquid, Gelusil, Gibbsite (Al(OH)3), Higilite, Higilite H 31S, Higilite H 32, Higilite H 42, Hychol 705, Hydrafil, Hydral 705, Hydral 710, Hydrated Alumina, Hydrated aluminum oxide, Kudrox, Liquigel, Maalox [Wiki], Maalox HRF, Maalox Plus, Martinal, Martinal A, Martinal A/S, Martinal F-A, Mylanta [Wiki], P 30BF, Reheis F 1000, Simeco Suspension, Tricreamalate, Trihydrated alumina, trihydroxidoaluminium, Trihydroxyaluminum, Trisogel, WinGel

Aluminium trihydrate is initially derived from bauxite ore, before being refined into a fine white powder.  

Aluminium trihydrate (also known as ATH and aluminium trihydroxide, chemical formula Al (OH)3) is initially derived from bauxite ore, before being refined into a fine white powder.

Annual production of Aluminium trihydrate is around 100 million tons which is nearly all produced through the Bayer process.

The Bayer process dissolves bauxite (Aluminium Ore) in sodium hydroxide at elevated temperatures.

Aluminium trihydrate is then separated from the solids that remain after the heating process.

The solids remaining after the Aluminium trihydrate is removed is highly toxic and presents environmental issues.

Aluminium trihydrate are available in different uncoated and coated grades, with average particle size varying from 2 microns to 80 microns as per application.

Aluminium trihydrate is a common primary ingredient present in most solid surface material and accounts for as much as 70% of the total product.

Aluminium trihydrate is used as a filler for epoxy, urethane, or polyester resins, where fire retardant properties or increased thermal conductivity are required.

Aluminium trihydrate is white in color.

Aluminium trihydrate is a flame retardant and smoke suppressant.

Aluminium trihydrate thermodynamic properties, endothermic dehydration cools the plastic 6 rubber parts and dilutes the combustible gases with water vapours that is generated in case of fire.

Aluminium trihydrate is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 1 000 000 to < 10 000 000 tonnes per annum. Aluminium trihydrate is used by consumers, in articles, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing. Aluminium trihydrate is a halogen-free, environmentally friendly flame retardant and smoke suppressant filler for plastics and rubber. Aluminium trihydrate is suitable for a broad range of applications including solid surface, composites and electrical insulation. Aluminium trihydrate is a white, translucent powder that is also called aluminum hydroxide. Aluminium trihydrate is obtained from Bauxite. When Aluminium trihydrate is strongly heated, Aluminium trihydrate will convert to Aluminum oxide with the release of water. Aluminium trihydrate is used as a base in the preparation of transparent lake pigments. Aluminium trihydrate is also used as an inert filler in paints and tends to increase the transparency of colors when dispersed in oils. Aluminium trihydrate is used commercially as a paper coating, flame retardant, water repellant, and as a filler in glass, ceramics, inks, detergents, cosmetics, and plastics. Aluminium trihydrate, Al(OH)3, is found in nature as the mineral gibbsite (also known as hydrargillite) and Aluminium trihydrate three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium trihydrate is amphoteric, i.e., Aluminium trihydrate has both basic and acidic properties. Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina (Al2O3), the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite. Aluminium trihydrate also forms a gelatinous precipitate in water. Aluminium trihydrate is a non-halogen fire retardant and smoke suppressant. Aluminium trihydrate is a major mineral fire retardant being the largest selling fire retardant additive in the world. Aluminium trihydrate is used commercially as a paper coating, flame retardant, water repellant, and as a filler in glass, ceramics, inks, detergents, cosmetics, and plastics. When strongly heated, Aluminium trihydrate decomposes into aluminium oxide with release of water following an endothermic reaction. Aluminium trihydrate (ATH or hydrated alumina) is a non-toxic, non-corrosive, flame retardant and smoke suppressant utilized in elastomeric applications. Aluminium trihydrate is the most frequently used flame retardant in the world. Aluminium trihydrate is a very effective flame retardant due to Aluminium trihydrate thermodynamic properties which absorb heat and release water vapor. Aluminium trihydrate releases its 35% water of crystallization as water vapor when heated above 205°C. The resulting endothermic reaction cools Aluminium trihydrate below flash point, reducing the risk of fire and acts as a vapor barrier to prevent oxygen from reaching the flame. Typical loadings vary from 20 phr to 150 phr. Because many polymers like polyethylene and polypropylene process above 200°C, these polyolefins should use magnesium hydroxide as a flame retardant filler since Aluminium trihydrate water of hydration releases at approximately 325°C. Aluminium trihydrates are obtained by digestion of bauxite throughout the Bayer process. Aluminium trihydrate starts to remove constitution water above 180°C Water removal cools the surface and eliminates entry of oxygen, which confers flame retardant properties and smoke suppressant. Accordingly Aluminium trihydrate is a necessary raw material for products like rubber, polyurethane, polyester, silicone, thermoplastic, cables, etc. with fire retardant properties. Aluminium trihydrate has a number of common names used throughout the chemical industry which include: Hydrate Alumina, Alumina Hydrate, Aluminium Tri Hydroxide, ATH, Aluminium Hydrate and Aluminium Hydroxide. Aluminium trihydrate is a white, odorless, powdery, solid substance. Aluminium trihydrate demonstrates a very low solubility in water but is considered to be amphoteric, meaning Aluminium trihydrate will dissolve in both acids or a strong alkali. The most common use of Aluminium trihydrate is for the production of aluminum metal. Aluminium trihydrate is also used as a flame retardant and smoke suppressant filler in polymers such as rubber products and carpet backing. Aluminium trihydrate is a white filling material that provides flame retardant and self-extinguishing properties for polyester resins and gelcoats. Aluminium trihydrate exposes water molecules within the body at high temperatures to reduce flame spread and smoke formation. Aluminium trihydrate is used in GRP pipe applications, in acrylic applications and in other multicomponent applications. Aluminum trihydrate (also known as aluminum hydrate, alumina hydrate, aluminum hydroxide, or ATH) is a filler, extender pigment, and bodying agent in oil- and water-borne paint that does not greatly affect the color of the paint. This is an 8-micron median particle size extender that is a white to tan colored powder and can be added to paint to impart transparency to the paint film. Aluminium trihydrate is the most widely used flame retardant in commercial coatings due to Aluminium trihydrate versatility and low cost. Aluminium trihydrate can be used in a wide range of paint binders at processing temperatures below 220°C. Aluminium trihydrate is non-toxic, halogen-free, chemically inert, and has low abrasiveness. Additional benefits are acid resistance and smoke suppression. At about 220°C, Aluminium trihydrate begins to decompose endothermically releasing approximately 35% of Aluminium trihydrate weight as water vapor. AI2O3•3H2O + HEAT —–> AI2O3 + 3 H2O

Aluminium trihydrate acts as a heat sink thereby retarding pyrolysis and reducing the burning rate.

The water vapor released has an added effect of diluting combustion gases and toxic fumes.

Aluminium trihydrate is the hydrated oxide of aluminium.

Aluminium hydrate is separated from bauxite ore using the Bayer process, with average particle size ranging from 80-100 micron.

The block crystals of alumina hydrate impart good chemical reactivity.

Alumina hydrate can react with a base as well as an acid, and finds use in many applications as raw material.

After drying, alumina hydrate is ground using mechanical mills and ceramic lined ball mills to obtain finer particle sizes.

Hindalco manufactures ground hydrate with different particle size (5-15 micron) distribution.

Surface-treated fine hydrate as well as super-ground fine hydrate (1-2.5 micron) are also available.

Aluminium trihydrate obtained in the Bayer process, is calcined at temperature above 1200°C and up to 1600°C to manufacture special grade alumina.

During calcinations, alumina hydrate crystals lose bound moisture and recrystallise to form alumina crystals.

The particle size of alumina remains at 85-100 micron.

Special alumina contains predominantly alpha phase.

The degree of calcination is a measure of the hardness of alumina – soft to hard.

Coarse alumina is classified based on the soda (Na2O) content:

Low soda alumina – Na2O <0.1% Medium soda alumina - 0.1% < Na2O <0.2% Normal Soda alumina - 0.20% < Na2O < 0.45% Calcined alumina is ground in fluid energy mills or ceramic lined ball mills to meet the desired particle size required by the customers. Hindalco manufactures fine alumina with varying particle size (0.5 to 8 micron) and distribution. Low soda, medium soda and normal soda type are available in fine alumina also. The global Aluminium trihydrate market size was valued at USD 1.5 billion in 2020 and is projected to reach USD 1.9 billion by 2025, growing at a cagr 5.5% from 2020 to 2025. The major drivers for the market include the rising consumer demand for Aluminium trihydrate in different applications and enduse industries, such as flame retardants, and paints & coatings. However, the substitutes present in the market, for instance, magnesium hydroxide, can restrain the market growth. Covid-19 Impact On The Global Aluminium trihydrate Market: The global Aluminium trihydrate market is expected to witness a moderate decrease in Aluminium trihydrate growth rate in 2020-2021, as the Aluminium trihydrate industry witness a significant decline in Aluminium trihydrate production. Aluminium trihydrate has affected the market for Aluminium trihydrate manufacturers catering to the glass and rubber industries, which were not considered essential. Moreover, most of the global companies operating in this market are based in Asia Pacific, the US, and European countries, which are adversely affected by the pandemic. These companies having their manufacturing units in China and other Asian countries are also severely affected. Therefore, disruptions in the supply chain have resulted in hampering production units due to a lack of raw materials and workforce. Aluminium trihydrate Market Dynamics: Driver: Increasing demand for non-halogenated flame retardants: The growing number of residential and commercial establishments has increased the possibilities of explosions and fire-related accidents.  Therefore, several countries across North America and Europe have mandated stringent fire safety regulations and protocols. This has led to the increased use of flame retardants in buildings to meet these government regulations. The major application of flame retardants is in electric wire insulation in building & construction, and transportation. Flame retardants are used in circuit boards, electronic casing, and cables & wire systems. Stringent fire safety standards to reduce the spread of fires in residential and commercial buildings are driving the demand for halogen-free flame retardants. Opportunities: Use of Aluminium trihydrate in water treatment plants Aluminium trihydrate (alum) is the most common coagulant used in water and wastewater treatment. The main purpose of using alum in these applications is to improve the settling of suspended solids and color removal. Alum is also used to remove phosphate from wastewater treatment effluent. Thus, the growing urbanization in emerging economies, such as China and India, is expected to fuel the demand for water treatment plants in residential areas. Nevertheless, many people still lack access to safe water and suffer from preventable water-borne microbial diseases leading to the increased demand for wastewater treatment plants. Thus, the use of aluminum hydroxide in water treatment plants in residential areas is expected to act as an opportunity for the growth of the Aluminium trihydrate market across the globe. Challenges:  Environmental issues related to alumina production: Alumina production leads to bauxite residue, also known as red mud. The disposal of bauxite residue/red mud is a challenge due to relatively large volumes, occupying land areas, and the alkalinity of the residue and the run-off water. Only a very small proportion of the bauxite residue produced are re-used in any way. Although the residue has a number of characteristics of environmental concern, the most immediate and apparent barrier to remediation and utilization is Aluminium trihydrate high alkalinity and sodicity. The high pH of the bauxite residue is a problem from both a health and safety point-of-view. This can pose a challenge for the Aluminium trihydrate market. Applications of Aluminium trihydrate: Over 90% of all Aluminium trihydrate produced is converted to Aluminium Oxide (alumina) that is used to manufacture aluminum. As a flame retardant, Aluminium trihydrate is chemically added to a polymer molecule or blended in with a polymer to suppress and reduce the spreading of a flame through a plastic. Aluminium trihydrate is also used as an antacid that can be ingested in order to buffer the pH within the stomach. Aluminium trihydrate is the hydrated oxide of aluminium. Aluminium trihydrate is separated from ore bauxite using Bayer process with average particle size ranging from 80-100 micron. The blocky crystals of Aluminium trihydrate impart good reactivity. Aluminium trihydrate can react with a base as well as an acid and finds many applications as raw material. Aluminium trihydrate is used in the manufacture of many inorganic chemicals like: Non- ferric alum Poly aluminium chloride Aluminium fluoride Sodium aluminate Catalysts Glass Aluminium trihydrate gel Alumina hydrate is available in wet as well as dry form. Fine hydrate: Aluminium trihydrate contain 3 molecules of water. On exposure to heat above 220°C, alumina hydrate decomposes into aluminium oxide (alumina) and water. This irreversible, endothermic reaction process makes alumina hydrate an effective flame retardant. Also, the smoke generated by decomposition is non-corrosive and non-poisonous. Ground alumina hydrate is used as fire retardant filler in applications like polymer composites, cable compounds, solid surface counter tops, etc. Uses of Aluminium trihydrate: Of the Common fillers used in Plastics, Rubber, FRP, SMC, DMC moulding and other polymers only Aluminium trihydrate has flame retarding and smoke suppressing properties as well as being an economical resin extender.  Aluminium trihydrate is used in polyester resins. However with increased attention being given to smoke & toxic fume emissions, Aluminium trihydrate has found large volume application in vinyl as a low smoke, non toxic replacement for antimony and in polyurethane, latex, neoprene foam system, Rubber, wire & Cable insulation, vinyl walls & flooring coverings and epoxies. Aluminium trihydrate acts as a flame retardant and smoke suppressor because of Aluminium trihydrate thermodynamic properties. Aluminium trihydrate endothermic dehydration cools the plastic & Rubber parts and dilute with water vapour those combustible gases that do escape. The latter is probably the main phenomenon associated with smoke suppression other excellent performance include electrical and track resistance. Aluminium trihydrate widely use in Paper Industries as a whitening agent in place of titanium dioxide. Aluminium trihydrate is also use in Paints Industries. Aluminium trihydrate can replace upto 25% of the Titanium dioxide pigment & therefore is an economical extender reducing production cost. Fire retardant filler: Aluminium trihydrate also finds use as a fire retardant filler for polymer applications. Aluminium trihydrate is selected for these applications because Aluminium trihydrate is colorless (like most polymers), inexpensive, and has good fire retardant properties. Magnesium hydroxide and mixtures of huntite and hydromagnesite are used similarly. Aluminium trihydrate decomposes at about 180 °C (356 °F), absorbing a considerable amount of heat in the process and giving off water vapour. In addition to behaving as a fire retardant, Aluminium trihydrate is very effective as a smoke suppressant in a wide range of polymers, most especially in polyesters, acrylics, ethylene vinyl acetate, epoxies, polyvinyl chloride (PVC) and rubber. Precursor to Al compounds: Aluminium trihydrate is a feedstock for the manufacture of other aluminium compounds: calcined aluminas, aluminium sulfate, polyaluminium chloride, aluminium chloride, zeolites, sodium aluminate, activated alumina, and aluminium nitrate. Freshly precipitated Aluminium trihydrate forms gels, which are the basis for the application of aluminium salts as flocculants in water purification. This gel crystallizes with time. Aluminium trihydrate gels can be dehydrated (e.g. using water-miscible non-aqueous solvents like ethanol) to form an amorphous Aluminium trihydrate powder, which is readily soluble in acids. Heating converts Aluminium trihydrate to activated aluminas, which are used as desiccants, adsorbent in gas purification, and catalyst supports. Pharmaceutical: Under the generic name "algeldrate", Aluminium trihydrate is used as an antacid in humans and animals (mainly cats and dogs). Aluminium trihydrate is preferred over other alternatives such as sodium bicarbonate because Al(OH)3, being insoluble, does not increase the pH of stomach above 7 and hence, does not trigger secretion of excess acid by the stomach. Brand names include Alu-Cap, Aludrox, Gaviscon or Pepsamar. Aluminium trihydrate reacts with excess acid in the stomach, reducing the acidity of the stomach content, which may relieve the symptoms of ulcers, heartburn or dyspepsia. Such products can cause constipation, because the aluminium ions inhibit the contractions of smooth muscle cells in the gastrointestinal tract, slowing peristalsis and lengthening the time needed for stool to pass through the colon. Some such products are formulated to minimize such effects through the inclusion of equal concentrations of magnesium hydroxide or magnesium carbonate, which have counterbalancing laxative effects. Aluminium trihydrate is also used to control hyperphosphatemia (elevated phosphate, or phosphorus, levels in the blood) in people and animals suffering from kidney failure. Normally, the kidneys filter excess phosphate out from the blood, but kidney failure can cause phosphate to accumulate. The aluminium salt, when ingested, binds to phosphate in the intestines and reduce the amount of phosphorus that can be absorbed. Precipitated Aluminium trihydrate is included as an adjuvant in some vaccines (e.g. anthrax vaccine). One of the well-known brands of Aluminium trihydrate adjuvant is Alhydrogel, made by Brenntag Biosector. Since Aluminium trihydrate absorbs protein well, Aluminium trihydrate also functions to stabilize vaccines by preventing the proteins in the vaccine from precipitating or sticking to the walls of the container during storage. Aluminium trihydrate is sometimes called "alum", a term generally reserved for one of several sulfates. Vaccine formulations containing Aluminium trihydrate stimulate the immune system by inducing the release of uric acid, an immunological danger signal. This strongly attracts certain types of monocytes which differentiate into dendritic cells. The dendritic cells pick up the antigen, carry Aluminium trihydrate to lymph nodes, and stimulate T cells and B cells. Aluminium trihydrate appears to contribute to induction of a good Th2 response, so is useful for immunizing against pathogens that are blocked by antibodies. However, Aluminium trihydrate has little capacity to stimulate cellular (Th1) immune responses, important for protection against many pathogens, nor is Aluminium trihydrate useful when the antigen is peptide-based. Aluminium trihydrate is used in various industries as: Aluminium trihydrate is used as a raw material in the production of Aluminium chemicals Aluminium trihydrate is used as a raw material in the manufacture of glass and glazes Aluminium trihydrate is used as a raw material in catalyst production Aluminium trihydrate is used as a flame retardant and smoke suppressant filler in plastics (for example: Cables, rubber products and carpet backing) Aluminium trihydrate is used as a raw material for fertilizers, and fiber cement board products Aluminium trihydrate is used as an extender and a bodying agent in paper, solvent- and water-borne paints, UV-curable coatings, inks, and adhesives Aluminium trihydrate is used as a polishing and cleansing agent Mould wash and separating agent Aluminium trihydrate is used as a filler of cast polymer products such as onyx and solid surfaces Uses at industrial sites: Aluminium trihydrate is used in the following products: coating products, fillers, putties, plasters, modelling clay, polymers and washing & cleaning products. Aluminium trihydrate has an industrial use resulting in manufacture of another substance (use of intermediates). Aluminium trihydrate is used in the following areas: mining, building & construction work and formulation of mixtures and/or re-packaging. Aluminium trihydrate is used for the manufacture of: chemicals, furniture, plastic products and rubber products. Release to the environment of Aluminium trihydrate can occur from industrial use: in the production of articles, as an intermediate step in further manufacturing of another substance (use of intermediates), formulation of mixtures, manufacturing of Aluminium trihydrate and in processing aids at industrial sites. Other release to the environment of Aluminium trihydrate is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), outdoor use, indoor use in long-life materials with low release rate (e.g. flooring, furniture, toys, construction materials, curtains, foot-wear, leather products, paper and cardboard products, electronic equipment) and outdoor use in long-life materials with low release rate (e.g. metal, wooden and plastic construction and building materials). Consumer Uses: Aluminium trihydrate is used in the following products: cosmetics and personal care products, coating products, inks and toners, fillers, putties, plasters, modelling clay, pharmaceuticals, adhesives and sealants, washing & cleaning products, lubricants and greases and polishes and waxes. Release to the environment of Aluminium trihydrate can occur from industrial use: formulation of mixtures and formulation in materials. Other release to the environment of Aluminium trihydrate is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners) and outdoor use. Widespread uses by professional workers: Aluminium trihydrate is used in the following products: inks and toners, coating products, fillers, putties, plasters, modelling clay, washing & cleaning products, adhesives and sealants, cosmetics and personal care products, lubricants and greases and polishes and waxes. Aluminium trihydrate is used in the following areas: building & construction work, printing and recorded media reproduction, formulation of mixtures and/or re-packaging and agriculture, forestry and fishing. Aluminium trihydrate is used for the manufacture of: textile, leather or fur and wood and wood products. Other release to the environment of Aluminium trihydrate is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners) and outdoor use. Aluminium trihydrate is characterised by:  High purity  High whiteness  Relatively low density (2.4g/cm3) compared to other mineral fillers (typically 2.7g/cm3)    Medium Mohs hardness of 3  Decomposition around 180oC, releasing water (making Aluminium trihydrate an excellent halogen-free flame retardant) Properties of Aluminium trihydrate: Aluminium trihydrate is amphoteric. In acid, Aluminium trihydrate acts as a Brønsted–Lowry base. Aluminium trihydrate neutralizes the acid, yielding a salt: 3 HCl + Al(OH)3 → AlCl3 + 3 H2O In bases, Aluminium trihydrate acts as a Lewis acid by binding hydroxide ions: Al(OH)3 + OH− → [Al(OH)4]− Physical Properties: Powdery substance Odorless Non-carcinogenic Aluminium trihydrate adds thermal properties that provide translucency and whiteness Solid surface material Non-smoking Low-toxicity Halogen-free Flame retardant Performance Benefits of Aluminium trihydrate: Flame retardant / smoke suppressant Ultra-white / translucent High purity – blush resistance Faster gel time Low viscosity / higher loadings Higher mechanical properties Production of Aluminium trihydrate: Virtually all the Aluminium trihydrate used commercially is manufactured by the Bayer process which involves dissolving bauxite in sodium hydroxide at temperatures up to 270 °C (518 °F). The waste solid, bauxite tailings, is removed and Aluminium trihydrate is precipitated from the remaining solution of sodium aluminate. This Aluminium trihydrate can be converted to aluminium oxide or alumina by calcination. The residue or bauxite tailings, which is mostly iron oxide, is highly caustic due to residual sodium hydroxide. Aluminium trihydrate was historically stored in lagoons; this led to the Ajka alumina plant accident in 2010 in Hungary, where a dam bursting led to the drowning of nine people. An additional 122 sought treatment for chemical burns. The mud contaminated 40 square kilometres (15 sq mi) of land and reached the Danube. While the mud was considered non-toxic due to low levels of heavy metals, the associated slurry had a pH of 13. Structure of Aluminium trihydrate: Al(OH)3 is built up of double layers of hydroxyl groups with aluminium ions occupying two-thirds of the octahedral holes between the two layers. Four polymorphs are recognized. All feature layers of octahedral Aluminium trihydrate units, with hydrogen bonds between the layers. The polymorphs differ in terms of the stacking of the layers. All forms of Al(OH)3 crystals are hexagonal: Gibbsite is also known as γ-Al(OH)3 or α-Al(OH)3 Bayerite is also known as α-Al(OH)3 or β-Aluminium trihydrate Nordstrandite is also known as Al(OH)3 Doyleite Hydrargillite, once thought to be Aluminium trihydrate, is an aluminium phosphate. Nonetheless, both gibbsite and hydrargillite refer to the same polymorphism of Aluminium trihydrate, with gibbsite used most commonly in the United States and hydrargillite used more often in Europe. Hydrargillite is named after the Greek words for water (hydra) and clay (argylles). Safety of Aluminium trihydrate: In the 1960s and 1970s Aluminium trihydrate was speculated that aluminium was related to various neurological disorders, including Alzheimer's disease. Since then, multiple epidemiological studies have found no connection between exposure to environmental or swallowed aluminium and neurological disorders, though injected aluminium was not looked at in these studies. Neural disorders were found in experiments on mice motivated by Gulf War illness (GWI). Aluminium trihydrate injected in doses equivalent to those administered to the United States military, showed increased reactive astrocytes, increased apoptosis of motor neurons and microglial proliferation within the spinal cord and cortex. Identifiers of Aluminium trihydrate: CAS Number: 21645-51-2 ChEBI: CHEBI:33130 ChEMBL: ChEMBL1200706 ChemSpider: 8351587 DrugBank: DB06723 ECHA InfoCard: 100.040.433 KEGG: D02416 PubChem CID: 10176082 RTECS number: BD0940000 UNII: 5QB0T2IUN0 CompTox Dashboard (EPA): DTXSID2036405 InChI: InChI=1S/Al.3H2O/h;3*1H2/q+3;;;/p-3 Key: WNROFYMDJYEPJX-UHFFFAOYSA-K A02AB02 (WHO) (algeldrate) InChI=1/Al.3H2O/h;3*1H2/q+3;;;/p-3 Key: WNROFYMDJYEPJX-DFZHHIFOAJ SMILES: [OH-].[OH-].[OH-].[Al+3] CAS number: 21645-51-2 EC number: 244-492-7 Hill Formula: AlH₃O₃ Chemical formula: Al(OH)₃ * x H₂O Molar Mass: 78 g/mol HS Code: 2818 30 00 Quality Level: MQ200 Properties of Aluminium trihydrate: Chemical formula: Al(OH)3 Molar mass: 78.003 g·mol−1 Appearance: White amorphous powder Density: 2.42 g/cm3, solid Melting point: 300 °C (572 °F; 573 K) Solubility in water: 0.0001 g/(100 mL) Solubility product (Ksp): 3×10−34 Solubility: soluble in acids and alkalis Acidity (pKa): >7

Isoelectric point: 7.7

Density: 2.42 g/cm3 (20 °C)

Melting Point: 300 °C Elimination of water of crystallisation

pH value: 8 – 9 (100 g/l, H₂O, 20 °C) (slurry)

Vapor pressure: <0.1 hPa (20 °C) Molecular Weight: 81.028 g/mol Hydrogen Bond Donor Count: 3 Hydrogen Bond Acceptor Count: 3 Rotatable Bond Count: 0 Exact Mass: 81.0132325 g/mol Monoisotopic Mass: 81.0132325 g/mol Topological Polar Surface Area: 3Ų Heavy Atom Count: 4 Complexity: 0 Isotope Atom Count: 0 Defined Atom Stereocenter Count: 0 Undefined Atom Stereocenter Count: 0 Defined Bond Stereocenter Count: 0 Undefined Bond Stereocenter Count: 0 Covalently-Bonded Unit Count: 4 Compound Is Canonicalized: Yes Thermochemistry of Aluminium trihydrate: Std enthalpy of formation (ΔfH⦵298): −1277 kJ·mol−1 Specifications of Aluminium trihydrate: Identity: conforms Chloride (Cl): ≤ 0.01 % Sulfate (SO₄): ≤ 0.05 % Fe (Iron): ≤ 0.01 % Na (Sodium): ≤ 0.3 % Loss on ignition (700 °C): 30.0 - 35.0 % Bulk density: about 90 Particle size (< 150 µm): about 90 Related compounds of Aluminium trihydrate: Boric acid Gallium(III) hydroxide Indium(III) hydroxide Thallium(III) hydroxide Scandium(III) hydroxide Sodium oxide Aluminium oxide hydroxide Names of Aluminium trihydrate: Regulatory process names: Aluminium hydroxide aluminium hydroxide Aluminum hydroxide, dried IUPAC names: Alumina hydrate ALUMINA TRIHYDRATE Alumina trihydrate ALUMINIUM HYDROXIDE Aluminium Hydroxide Aluminium hydroxide aluminium hydroxide Aluminium Hydroxide Aluminium hydroxide aluminium hydroxide Aluminium hydroxide, Alumina hydrate Aluminium hydroxide_JS Aluminium hydroxyde aluminium trihydrate Aluminium trihydrate Aluminium trihydroxide aluminium trihydroxide aluminium(3+) ion trihydroxide Aluminium(3+) trihydroxide aluminium(3+) trihydroxide aluminium(III) hydroxide Aluminiumhydroxid aluminuim hydroxide ALUMINUM HYDROXIDE Aluminum Hydroxide Aluminum hydroxide aluminum hydroxide Aluminum hydroxide Aluminum hydroxide (Al(OH)3) Aluminum hydroxide (Al(OH)3) Aluminum Trihydrate Aluminum trihydrate aluminum trihydrate Aluminum trihydroxide aluminum trihydroxide ATH Hydrate Sulcabai Preferred IUPAC name: Aluminium hydroxide Systematic IUPAC name: Trihydroxidoaluminium Trade names: AB H-Series Alumina Trihydrate Actilox ALH-…… ALOLT-………. Alumina Hydrate Alumina hydrate Aluminium hydrate Aluminium Hydroxide Aluminium hydroxide aluminium hydroxide Aluminium trihydroxide Aluminiumhydroxid Aluminum hydroxide Aluminum hydroxide highly dispersed precipitated aluminum trihydrate Apyral BARIACE BARIFINE Bayerit Geloxal Hidróxido de aluminio Hydrate Hydrated alumina hydroxid hlinitý HYMOD® Surface-Treated Alumina Trihydrate JR-800, MT-500SA etc. KB-30, HS , HC, Hydrate, Aluminium hydroxide MARTIFILL® MARTIFIN® MARTINAL® MICRAL® Alumina Trihydrate MOLDX® Optimized Alumina Trihydrate ONYX ELITE® Alumina Trihydrate R-11P SB Alumina Trihydrate Sigunit SSP STR T-Lite VOGA Other names: Aluminium oxide, hydrate Aluminum hydroxide (Al(OH)3) Aluminum oxide (Al2O3), hydrate Aluminic acid Aluminic hydroxide Alumanetriol Aluminium(III) hydroxide Aluminium hydroxide Aluminium trihydroxide Hydrated alumina Orthoaluminic acid Other identifiers: 106152-09-4 1071843-34-9 12040-59-4 12252-70-9 128083-27-2 1302-29-0 1333-84-2 13783-16-9 151393-94-1 156259-59-5 159704-77-5 16657-47-9 1847408-13-2 21645-51-2 227961-51-5 51330-22-4 546141-62-2 546141-68-8 8012-63-3 8064-00-4