MONOALUMINIUM PHOSPHATE
MONOALUMINIUM PHOSPHATE
Monoaluminium phosphate is an inorganic compound with the chemical formula Al(H2PO4)3, typically encountered as a white powder or viscous solution that is highly soluble in water and has acidic properties due to the presence of dihydrogen phosphate groups.
Upon heating, monoaluminium phosphate undergoes polycondensation, forming a thermally stable, glass-like phosphate network that makes it ideal for use in ceramics, refractories, and fire-retardant coatings.
Monoaluminium phosphate acts as a ceramic binder, corrosion-resistant additive, and flame-retardant agent in high-performance industrial applications such as foundry molds, electronic
CAS Number: 7784-30-7
EC Number: 232-056-9
Chemical formula: Al(H2PO4)3
Molar mass: 121.9529 g/mol
Synonyms: Aluminum phosphate, 7784-30-7, Aluminum monophosphate, Monoaluminum phosphate, ALUMINIUM PHOSPHATE, Aluminumphosphate, UNII-F92V3S521O, Aluminum phosphate , Phosphaljel, Phosphalugel, F92V3S521O, Aluminum acid phosphate, Aluphos, Aluminum phosphate (USP), Aluminophosphoric acid, aluminium orthophosphate, Aluminiumphosphat, MFCD00003430, Aluminiumphosphat , Aluminum phosphate (1:1), Aluminum monophosphate; Aluminum orthophosphate;Phosphalutab; Phosphaluvet; Rehydraphos, FFB 32, EINECS 232-056-9, Phosphoric acid, aluminum salt (1:1), Aluminium orthophosphate, natural, Phosphaljel (TN), Aluminum phosphate gel, Aluminium phosphate gel, Al.PO4, Aluminum Phosphate powder, Aluminium phosphate, pure, Aluminum Phosphate B111, Aluminum Phosphate B210, EC 232-056-9, Aluminum Phosphate suspension, Aluminum phosphate, Puratronic, CHEMBL3833315, DTXSID5064839, 5455AF, AKOS015856690, DB14517, 56574-68-6, 98499-64-0, FT-0622223, D02862, UNII-F41V936QZM component ILRRQNADMUWWFW-UHFFFAOYSA-K, 56574-68-6 , 98499-64-0, Aluminium phosphate, Aluminiumphosphat , ALUMINUM DIHYDROGEN PHOSPHATE, Aluminum phosphate , MFCD00003430, Phosphate d’aluminium , TB6450000, [7784-30-7] , 135151-77-8 , 13530-50-2, 13765-93-0, 150828-31-2 , 2,4,5-Trioxa-1λ5-phospha-3-aluminabicyclo[1.1.1]pentane 1-oxide, 231-072-3, 236-875-2, 36201-72-6 , 37324-42-8 , 51668-55-4 , 52350-11-5 , 8022-59-1 , 89686-54-4, 93237-81-1 , aluminium orthophosphate, ALUMINIUM PHOSPHATE|ALUMINIUM(3+) PHOSPHATE, Aluminium phosphic acid, ALUMINIUM(3+) ION PHOSPHATE, Aluminiumphosphat , Aluminiumphosphate, Aluminophosphoric acid, Aluminum acid phosphate, ALUMINUM HYDROXYPHOSPHATE SULFATE, Aluminum monophosphate, Aluminum phosphate (1:1), Aluminum phosphate (USP), Aluminum Phosphate B111, Aluminum Phosphate B210, Aluminum phosphate, meta, aluminum;phosphate, ALUMINUMPHOSPHATE, Aluphos, EINECS 232-056-9, Monoaluminum phosphate, MONO-ALUMINUM PHOSPHATE, Phosphaljel , Phosphaljel , Phosphalugel, phosphoric acid aluminium salt, Phosphoric acid, aluminum salt (1:1), UNII-F41V936QZM
Monoaluminium phosphate is an inorganic compound with the chemical formula Al(H2PO4)3.
Monoaluminium phosphate is the monobasic phosphate salt of aluminum, comprising one aluminum cation (Al³⁺) and three dihydrogen phosphate anions (H₂PO₄⁻).
Monoaluminium phosphate is typically encountered as a white powder or viscous solution that is highly soluble in water and has acidic properties due to the presence of dihydrogen phosphate groups.
Monoaluminium phosphate plays a critical role in both industrial applications and high-temperature material formulations, particularly because of its excellent binding, adhesive, and flame-retardant properties.
Upon heating, monoaluminium phosphate undergoes polycondensation, releasing water and forming a thermally stable, refractory phosphate network, making it invaluable in ceramics, refractories, and intumescent coatings.
In aqueous solution, Monoaluminium phosphate behaves as an acidic phosphate binder, and upon drying or heating, it undergoes dehydration reactions leading to the formation of aluminum metaphosphate and eventually aluminum pyrophosphate.
This transition makes Monoaluminium phosphate useful in the synthesis of phosphate ceramics, catalyst supports, and protective films.
Furthermore, due to its non-toxic, non-volatile, and chemically inert nature at ambient temperatures, Monoaluminium phosphate is widely used as a safe and environmentally friendly component in various formulations.
Monoaluminium phosphate is also used in combination with magnesium oxide or zinc oxide to create fast-setting phosphate cements, and it is often used as a binder in foundry molds, corrosion-resistant coatings, electronic materials, and flame-retardant formulations.
Monoaluminium phosphate’s strong bonding capability, both chemically and mechanically, with metals and ceramics is one of the key reasons for its versatility.
Monoaluminum Phosphate is a chemical compound.
In nature Monoaluminum Phosphate occurs as the mineral berlinite.
Many synthetic forms of aluminium phosphate are known.
They have framework structures similar to zeolites and some are used as catalysts, ion-exchangers or molecular sieves.
Commercial aluminium phosphate gel is available.
Monoaluminum Phosphate is also used in the pharmaceutical industry for manufacturing chemotherapeutic drugs.
Monoaluminum Phosphate occurs naturally in the form of the mineral berlinite.
Monoaluminum Phosphate is prepared chemically when soluble Aluminium salts are exposed to alkaline conditions.
Monoaluminum Phosphate is represented as AlPO4, which consists of hydrated Aluminium Orthophosphate.
The Monoaluminum Phosphate solutions form polymeric aggregates wherein equilibrium is reached very slowly.
Monoaluminum Phosphate forms soluble Aluminium salts and Phosphoric acid by slowly reacting with Gastric acid.
However, Monoaluminum Phosphate absorbs the bile acids weaker than Aluminium Hydroxide.
Here, we will learn what is Aluminium Phosphate, what is the formula for Aluminium Phosphate, what is Aluminium Phosphate used for, and the properties of Aluminium Phosphate.
Monoaluminum Phosphate is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 1 000 tonnes per annum.
Monoaluminum Phosphate is used by consumers, in articles, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.
Monoaluminium phosphate is colorless, odorless, extremely viscous liquid or white powder.
Monoaluminum Phosphate is used as a binder for refractory materials, mainly used in the electrical industry, high temperature furnaces, heat treatment resistance furnaces and electrical insulation.
Monoaluminum Phosphate is also used in petroleum, chemical, shipbuilding and space technology.
Monoaluminum Phosphate can also be used as an inorganic coating in conjunction with an organic coating.
Monoaluminium phosphate, Al(H₂PO₄)₃, exists most commonly as a colorless to white crystalline solid or a viscous aqueous solution, depending on its method of preparation and intended application.
Monoaluminium phosphate’s solution form is highly acidic, often with a pH around 1 to 2, which allows it to chemically interact with basic oxides and hydroxides in composite materials and reaction systems.
This acid-base reactivity is fundamental to Monoaluminium phosphate’s cement-forming and bonding capabilities.
Structurally, Monoaluminium phosphate consists of an Al³⁺ central ion surrounded by three H₂PO₄⁻ ligands.
Each ligand can form hydrogen bonds or coordinate through oxygen atoms, enabling cross-linking and polymeric chain formation during thermal curing or dehydration.
Upon heating (typically above 300–400°C), monoaluminium phosphate transforms into a glass-like, insoluble aluminum phosphate network through polycondensation, emitting water in the process.
This results in materials that are chemically and thermally resistant, making them ideal for refractory and anti-corrosive applications.
Monoaluminium phosphate is often synthesized via the reaction of aluminum hydroxide or aluminum salts (such as aluminum nitrate or aluminum sulfate) with phosphoric acid, followed by careful pH and temperature control.
The final product may be a clear acidic solution or a gel, depending on the concentration and intended use.
From a functional perspective, Monoaluminium phosphate acts as:
a ceramic binder in the production of high-strength, high-temperature ceramics and insulation materials,
a setting agent in chemically bonded phosphate ceramics (CBPCs),
a fire-retardant binder in intumescent coatings, where it contributes to the formation of carbonaceous foams that insulate and protect substrates from flames,
a corrosion-resistant additive in coatings for metals, especially in environments involving acids, alkalis, or high temperatures.
In electronics and optics, monoaluminium phosphate finds application as a bonding agent in glass-ceramic seals, especially where thermal expansion compatibility and chemical resistance are critical.
Monoaluminium phosphate’s electrically insulating properties and thermal stability also make it suitable for specific capacitor coatings and battery separator systems.
Additionally, Monoaluminium phosphate is frequently used in combination with boehmite (AlOOH), zinc phosphate, or borates in hybrid systems to enhance adhesion, improve flame retardancy, and control setting times.
In these formulations, Monoaluminium phosphate serves as both a reactive component and a functional performance enhancer, improving both the mechanical and chemical resistance of the final product.
Because Monoaluminium phosphate does not contain volatile organic compounds (VOCs) or heavy metals, it is considered environmentally safer than many traditional binders and additives.
This has made monoaluminium phosphate especially relevant in modern, sustainable material science.
Berlinite of Monoaluminum Phosphate:
AlPO4 is isoelectronic with Si2O4, silicon dioxide.
Berlinite looks like quartz and has a structure that is similar to quartz with silicon replaced by Al and P.
The AlO4 and PO4 tetrahedra alternate.
Like quartz, AlPO4 exhibits chirality and piezoelectric properties.
When heated, crystalline AlPO4 (berlinite) converts to tridymite and cristobalite forms, and this mirrors the behaviour of silicon dioxide.
Study of composition and structure of aluminum phosphate binder
In this article, theoretical analysis and different testing techniques were used to study the reaction pathways and synthesized products of phosphoric acid and aluminum hydroxide at different Al/P molar ratios.
The results show that: (a) When the molar ratio of phosphoric acid/aluminum hydroxide is 1:3, the reaction will produce stoichiometric aluminum dihydrogen phosphate (Al(H2PO4)3); (b) when Al(OH)3 is excessive, an intermediate, monohydroxy aluminum dihydrogen phospate (HO-Al-(H2PO4)2), will appear, which is unstable and will continue to react according to two reaction pathways, one is intramolecular dehydration to form phosphoric acid hydrogen-dihydrogen aluminum diphosphate (H2PO4)Al(HPO4); the other is intermolecular dehydration cross-linking to form a polymeric macromolecular aluminum phosphate H-((HPO4)(H2PO4)Al-O-HPO4-Al(H2PO4)-O)- nH.
The ratio of the two pathways is affected by the excess of Al(OH)3.
When the excess of Al(OH)3 continues to increase, the ratio of the second reaction path begins to increase and the viscosity of Monoaluminium phosphate gradually increases.
Adhesion experiments show that the aluminum dihydrogen phosphate has the best bonding performance benefiting from Monoaluminum Phosphate lower viscosity.
Market Overview of Monoaluminum Phosphate:
Monoaluminum phosphate is classified as the primary building block and a key ingredient in the synthesis of refractory materials.
In the commercial market, monoaluminum phosphate is highly recommended as a binding and curing material in the processing of high-temperature refractory materials.
These monoaluminum phosphate-based refractory materials are adopted in different end-use industries such as glass, ceramic and steel, to name a few.
Moreover, monoaluminum phosphate is adopted for the formulation of metal coating material.
Monoaluminum phosphate is colourless & odourless in nature as well as highly soluble in water & solvent at normal room temperature.
On an industrial scale, monoaluminum phosphate is synthesised through the acid-base neutralisation process between phosphoric acid and high-purity aluminium hydroxide.
Monoaluminum phosphate is commercially available in two forms: powder form and liquid form.
These forms of monoaluminum phosphate can be derived by changing the molar ratio of the reactants used during the acid-base neutralisation process.
The preparation of powder form monoaluminum phosphate requires excessive moles of phosphoric acid during the synthesis process.
Monoaluminum phosphate manufactures change the process parameters to tailor make monoaluminum phosphate according to the needs of end users, i.e., steel manufacturers and glass manufacturers, to name a few.
At a commercial level, monoaluminum phosphate manufacturers provide their products in different SKUs, i.e., in packs of different sizes, to cater to the demands of small and large end users.
Market Dynamics:
Monoaluminum phosphate is gaining potential as a key material for binding & curing applications in refractory applications, which are used in numerous industries such as steel, cement and glass, to name a few.
Increase in the production of glass, ceramic and steel is expected to create substantial demand for monoaluminum phosphate across the globe.
There has been significant growth in the infrastructure as well as commercial & residential construction sectors in high-growth regions such as China, India and other ASEAN countries in the recent past, primarily due to rapid growth in population, which has resulted in rapid growth in the demand for steel, cement, glass and nonferrous metals.
These factors are also creating potential demand for monoaluminum phosphate.
The steel industry alone has been consuming almost more than 50% of the total refractory volume consumption across the globe, and this is expected to steadily drive the demand for the monoaluminum phosphate-based refractory materials used by these industries as a result of increased manufacturing requirements and capacity expansions.
However, refractory businesses in several regions are suffering financial setbacks, which is likely to restrain the growth of the monoaluminum phosphate market.
Region Wise Trends:
China is expected continue to dominate the global monoaluminum phosphate market.
The rapid development of infrastructure and major industrial activities in the mining, metallurgy, glass, steel and cement sectors in the country is expected to fuel the demand for manufacturing plants that require better quality refractory materials, thereby promoting the growth of the monoaluminum phosphate market.
Increase in construction activity in commercial as well as residential sectors in ASEAN and India is expected to drive the demand for monoaluminum phosphate for cement production.
Furthermore, increase in the spending on infrastructure, especially in mega projects such as the redevelopment of Tokyo and Olympics in 2020, has led to the high demand for steel and excessive demand for monoaluminum phosphate.
In addition to the demand generated on account of mega projects, the introduction of economic stimulus packages by the government is also likely to boost the demand for steel, which is estimated to boost the monoaluminum phosphate market in developed regions such as North America & Europe.
The research report presents a comprehensive assessment of the market and contains thoughtful insights, facts, historical data, and statistically supported and industry-validated market data.
Monoaluminum Phosphate also contains projections using a suitable set of assumptions and methodologies.
The research report provides analysis and information according to market segments such as geographies, application, and industry.
Segmentation:
On the basis of form, the monoaluminum phosphate market can be segmented as:
Powder Monoaluminum Phosphate
Liquid Monoaluminum Phosphate
On the basis of application, the monoaluminum phosphate market can be segmented as:
Binder Agent
Curing agent
Coating formulation
On the basis of end use, the monoaluminum phosphate market can be segmented as:
Steel
Cement
Non-ferrous Metal
Glass
Others
Uses of Monoaluminum Phosphate:
Monoaluminium phosphate is colorless transparent viscous liquid or white powder, easily soluble in water, and the aqueous solution is acidic.
Strong chemical bonding, curing at room temperature, high temperature resistance, strong infrared absorption ability and good insulation.
Monoaluminium phosphate is mainly used in the electrical industry, high temperature furnaces, heat treatment resistance furnaces and electrical insulation.
Monoaluminum Phosphate is also used in petroleum, chemical, shipbuilding and space technology.
Monoaluminum Phosphate can also be used as an inorganic coating in conjunction with an organic coating.
Monoaluminum Phosphate is mainly used as binder and curing agent in the production of hi-temp refractorymaterials for kiln, spray paint,Fire clay, casting and foundry industry.
Mono Aluminum Phosphate has an Al2O3 content of 60-90%, for instance, corundum, mullite and sintered bauxite, which is used for bonding refractory materials.
Furthermore, Monoaluminum Phosphate produces a very good bond with fire clay, silicon carbide, and chromites within certain limitations, with quartz.
Monoaluminum Phosphate is good thermal shock stability, wear resistance and high temperature toughness, and in low and high temperature have good mechanical strength, after years of use, by the majority of refractories manufacturing and use manufacturers welcome.
Use refractory spray paint, fire clay, castable and binders for casting industry
Monoaluminum Phosphate is mainly used in the production of corundum brick for refractory industry.
Monoaluminium phosphate is colorless, odorless, highly viscous liquid or white powder that dissolves easily in water.
Monoaluminum Phosphate is used as the binder of refractory materials, mainly used in electrical industry, high temperature furnace, heat treatment resistance furnace and electrical insulation.
Monoaluminium phosphate is also used in petroleum, chemical industry, shipbuilding and space technology.
Monoaluminum Phosphate can also be used as a combination of inorganic coating and organic coating.
Ceramic and Refractory Binder:
Monoaluminium phosphate is used as a chemical binder in the manufacturing of ceramics, thermal insulators, and refractory linings due to its ability to form a heat-resistant phosphate network upon curing.
Flame-Retardant Coatings:
Monoaluminium phosphate serves as a key component in intumescent (swelling) fire-retardant coatings, where it forms a protective char layer that insulates substrates during combustion.
Foundry and Casting Applications:
Monoaluminium phosphate acts as a binder for sand molds and cores in metal casting, providing strength and heat resistance to withstand molten metal temperatures.
Corrosion-Resistant Paints and Coatings:
Added to protective paints and coatings for metals, especially in acidic and high-temperature environments, due to its chemical inertness and strong adhesion.
Phosphate Cement Systems:
Monoaluminium phosphate is used as a setting agent in chemically bonded phosphate ceramics (CBPCs) and phosphate-based cements, particularly for toxic waste encapsulation and rapid repair mortars.
Electronics and Glass-Ceramic Bonding:
Employed in sealing and bonding of glass-ceramic materials, especially where electrical insulation, thermal stability, and low thermal expansion are needed (e.g., sensors, capacitors).
Battery Separator and Insulation Layers:
Monoaluminium phosphate is used as a coating material in lithium battery separators and electrical insulation systems, providing chemical resistance and thermal protection.
Catalyst Binder:
Monoaluminium phosphate acts as a binder for heterogeneous catalysts, especially those used in dehydration or oxidative reactions, where high thermal resistance is essential.
Textile and Paper Fire Retardants:
Monoaluminium phosphate applied as a fire retardant treatment for textiles, paper, and wood products, contributing to charring and reducing flammability.
Adhesive for Composite Materials:
Monoaluminium phosphate is used as a high-temperature adhesive for ceramic, glass, and metal composites, ensuring bonding strength even under thermal stress.
Industry Uses:
Catalyst
Dyes
Intermediates
Laboratory chemicals
Pigments
Process regulators
Processing aids, specific to petroleum production
UNAVOIDABLE IMPURITY
Consumer Uses:
Monoaluminum Phosphate is used in the following products: coating products, fillers, putties, plasters, modelling clay, inks and toners, polymers, adhesives and sealants, pharmaceuticals and cosmetics and personal care products.
Other release to the environment of this substance 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.
Other Consumer Uses:
Building/construction materials not covered elsewhere
Catalyst
Fabric, textile, and leather products not covered elsewhere
Floor coverings
Furniture and furnishings not covered elsewhere
Paints and coatings
Plastic and rubber products not covered elsewhere
Other uses:
Along with aluminium hydroxide, aluminium phosphate is one of the most common immunologic adjuvants (efficiency enhancers) in vaccinations.
Aluminium adjuvant use is widespread due to their cheap price, long history of use, safety and efficiency with most antigens.
Monoaluminum Phosphate unknown how such salts function as adjuvants.
Similar to aluminum hydroxide, AlPO4 is used as an antacid.
Monoaluminum Phosphate neutralizes stomach acid (HCl) by forming AlCl3 with Monoaluminum Phosphate.
Up to 20% of aluminum from ingested antacid salts can be absorbed from the gastrointestinal tract – despite some unverified concerns about the neurological effects of aluminum, aluminum phosphate and hydroxide salts are thought to be safe as antacids in normal use, even during pregnancy and breastfeeding.
Additional uses for AlPO4 in combination with or without other compounds are white colorants for pigments, corrosion inhibitors, cements and dental cements.
Related compounds have also similar uses.
For example, Al(H2PO4)3 is used in dental cements, metal coatings, glaze compositions and refractory binders; and Al(H2PO4)(HPO4) is used cement and refractory binders and adhesives.
Properties of Monoaluminum Phosphate:
Aluminium dihydrogen phosphate is a type of colorless and odorless but extremely sticky liquid, freely soluble in water and solidifiable at normal room temperature.
Monoaluminum Phosphate has strong binding force in liquid or solid states and good resistance to peeling, high temperature, vibration and hi-temp air stream.
Besides Monoaluminum Phosphate has good infrared absorbability and insulativity.
Physical properties of Monoaluminum Phosphate:
Aluminium dihydrogen phosphate is a type of colorless and odorless but extremely stickyliquid, freely soluble in water and solidifiable at normal room temperature.
The liquid and solid have strong chemical binding force, high temperature resistance，vibration resistance,peelingresistance, and high temperature airflow erosion resistance.
And has good infrared absorption capacity and insulation.
Chemical Properties:
Now let us go through the chemical properties of Aluminium Phosphate AlPO4.
Aluminium Phosphate reacts with Hydrochloric Acid to form Aluminium Trichloride and Phosphoric acid.
The reaction is as follows:
AlPO4 + 3HCl → AlCL3 + H3PO4Aluminium Phosphate reacts with Magnesium Chloride to form Magnesium Phosphate and Aluminium Trichloride.
The reaction is given as follows:
2AlPO4 + 3MgCl2 → Mg3(Po4)2 + 2AlCl3
Structure of Monoaluminum Phosphate:
Monoaluminum Phosphate generally occurs as an anhydrous salt.
However, Monoaluminum Phosphate dihydrate and pentahydrate structures occur as well, which are represented as AlPO4.2H2O and AlPO4.5H2O.
The Aluminium Phosphate compound is formed by the Phosphate anion and Aluminium cation.
Monoaluminum Phosphate anhydrous salt structure is much similar to several other minerals like quartz and has a trigonal crystal structure.
However, Monoaluminum Phosphate dihydrate form has a structure similar to NaCl in which 6 cations are coordinated to 6 anions.
The structure of Aluminium Phosphate AlPO4 is shown below.
This representation is commonly used for organic molecules.
Chemical Formula of Aluminium Phosphate of Monoaluminum Phosphate:
Let us take a look at what is the chemical formula for aluminium phosphate.
Aluminium Phosphate is also called Aluminium Monophosphate or Mono-Aluminium Phosphate.
Monoaluminum Phosphate is formed by the Phosphate anion PO43-, and the Aluminium cation Al3+.
Hence, the chemical or molecular formula of Aluminium Phosphate is AlPO4.
Monoaluminum Phosphate occurs as a white crystalline powder.
However, Monoaluminum Phosphate is a colourless liquid in Monoaluminum Phosphate aqueous form.
Monoaluminum Phosphate is insoluble in water and occurs in the form of a mineral berlinite.
Aluminium phosphate is found in minerals like variscite and meta-variscite in Monoaluminum Phosphate dihydrate form.
Since Monoaluminum Phosphate has piezoelectric properties, Monoaluminum Phosphate is widely used in the electronic and electrical industries.
Now that you know about what is Aluminum Phosphate and what is the chemical formula for Aluminum Phosphate, let us take a look at some of Monoaluminum Phosphate properties.
Pharmacology and Biochemistry of Monoaluminum Phosphate:
MeSH Pharmacological Classification of Monoaluminum Phosphate:
Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level.
The classical agents (Freund’s adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens.
Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1).
Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens.
The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.
Mechanism of Action of Monoaluminum Phosphate:
Aluminum Acetate is an astringent.
An astrignent is a chemical that tends to shrink or constrict body tissues, usually locally after topical medicinal application.
The shrinkage or constriction is through osmotic flow of water (or other fluids) away from the area where the astringent was applied.
Astringent medicines cause shrinkage of mucous membranes or exposed tissues and are often used internally to check discharge of blood serum or mucous secretions.
This can happen with a sore throat, hemorrhages, diarrhea, or with peptic ulcers.
Externally applied astringents, which cause mild coagulation of skin proteins, dry, harden, and protect the skin.
Acne sufferers are often advised to use astringents if they have oily skin.
Astringents also help heal stretch marks and other scars.
Mild astringent solutions are used in the relief of such minor skin irritations as those resulting from superficial cuts, allergies, insect bites, or fungal infections such as athlete’s foot.
Production of Monoaluminium Phosphate:
Monoaluminium phosphate is typically produced via a controlled neutralization reaction between phosphoric acid (H₃PO₄) and an aluminum source such as aluminum hydroxide [Al(OH)₃], aluminum oxide (Al₂O₃), or aluminum salts like aluminum nitrate [Al(NO₃)₃] or aluminum sulfate [Al₂(SO₄)₃].
The reaction is carried out in aqueous medium under acidic conditions to favor the formation of the monobasic phosphate salt.
Typical Reaction:
Al(OH)3+3H3PO4→Al(H2PO4)3+3H2O
This reaction yields monoaluminium phosphate and water as a by-product.
The precise molar ratio of reactants and pH control are critical to ensure that only the monobasic form (Monoaluminium phosphate) is produced, rather than di- or tri-basic aluminum phosphates.
Production Steps:
Preparation of Solution:
A concentrated solution of phosphoric acid is prepared.
Aluminum hydroxide (or alternative aluminum compound) is slowly added under constant stirring.
Controlled Reaction:
The temperature is maintained between 50°C and 90°C to facilitate dissolution and reaction.
pH is closely monitored and maintained in the acidic range (pH ~1.5–2.5) to ensure formation of monoaluminium phosphate.
Aging and Homogenization:
The resulting slurry or solution is aged for several hours to ensure complete reaction and homogeneity.
For high-purity applications, filtration or centrifugation may be performed to remove any insoluble residues.
Formulation and Adjustment:
The final product can be formulated as a clear, viscous solution or spray-dried to form a fine, white powder, depending on the end use.
Stabilizers may be added to prevent premature polymerization or gelling during storage.
Quality Control:
Monoaluminium phosphate is tested for parameters such as P/Al molar ratio, viscosity, density, pH, and solubility.
Trace metal impurities (e.g., Fe, Na, Ca) are monitored, especially for electronic or high-performance applications.
General Manufacturing Information of Monoaluminum Phosphate::
Industry Processing Sectors:
All other basic inorganic chemical manufacturing
Custom compounding of purchased resin
Furniture and related product manufacturing
Paint and coating manufacturing
Paper manufacturing
Petroleum refineries
Plastic material and resin manufacturing
Plastics product manufacturing
Printing and related support activities
Reclamation
Synthetic dye and pigment manufacturing
Wholesale and retail trade
Related compounds of Monoaluminum Phosphate:
AlPO4·2H2O dihydrate is found as the minerals variscite and meta-variscite.
Aluminium phosphate dihydrate (variscite and meta-variscite) has a structure that can be regarded as an assembly of tetra- and octahedral units of phosphate anions, aluminium cations and water.
Al3+ ions are 6-coordinate and PO43- ions are 4-coordinate.
A synthetic hydrated form, AlPO4·1.5H2O is also known.
History of Monoaluminium Phosphate:
The origins of monoaluminium phosphate can be traced back to the early 20th century, during the broader exploration of phosphate chemistry for industrial and military purposes.
As phosphate compounds gained attention for their unique chemical reactivity, binding strength, and flame resistance, researchers began to investigate various metal phosphate salts, including those of aluminum.
Monoaluminium phosphate was first recognized as a useful acidic binder in the 1940s and 1950s, particularly during World War II, when the demand for high-temperature resistant materials and non-combustible coatings surged.
In this period, aluminum phosphates were studied intensively for use in thermal insulation, fireproofing of naval vessels, and aircraft component protection.
Monoaluminium phosphate emerged as a leading candidate due to its ability to form strong, insoluble, heat-resistant phosphate networks upon curing.
By the 1960s and 1970s, Monoaluminium phosphate began to be commercially produced and applied in the ceramics industry and refractory formulations, where its thermal stability and adhesive properties made it an ideal binder.
Monoaluminium phosphate’s use expanded further with the development of chemically bonded phosphate ceramics (CBPCs) in the 1980s and 1990s, as Monoaluminium phosphate played a critical role in forming fast-setting, chemically durable matrices for toxic waste encapsulation, dental cements, and structural repair materials.
In more recent decades, Monoaluminium phosphate has found a place in high-tech industries, including electronics, batteries, and optical materials, driven by its non-toxic, VOC-free, and flame-retardant nature.
With the push for sustainable and green chemistry solutions, monoaluminium phosphate continues to gain relevance due to its environmentally friendly profile and multifunctional performance.
Handling and Storage of Monoaluminum Phosphate:
Handling:
Use in well-ventilated areas.
Avoid inhalation of dusts or aerosols and prolonged skin contact.
Use non-reactive containers and tools, preferably glass or polyethylene, to avoid contamination and premature polymerization.
Prevent contact with alkalis or reactive metal powders that may neutralize or alter Monoaluminium phosphate.
Storage:
Store in a cool, dry place, away from moisture and direct sunlight.
Keep containers tightly sealed.
Aqueous solutions should be stored in acid-resistant plastic drums or containers (e.g., HDPE).
Avoid freezing for liquid Monoaluminium phosphate.
Monoaluminium phosphate may lead to precipitation or viscosity changes.
Reactivity and Stability of Monoaluminum Phosphate:
Chemical Stability:
Stable under recommended storage and handling conditions.
In aqueous form, Monoaluminium phosphate remains stable in acidic conditions but may polymerize or gel over time, especially when exposed to elevated temperatures.
Reactivity:
Reacts with alkaline substances, metal oxides, and strong bases, which can neutralize the acidic phosphate and alter Monoaluminium phosphate’s functionality.
May slowly dehydrate or condense upon heating, forming pyrophosphate or metaphosphate phases.
Hazardous Decomposition Products:
Upon combustion or high thermal degradation, may emit phosphorus oxides (POₓ) and water vapor.
First Aid Measures of Monoaluminum Phosphate:
Inhalation:
Move the person to fresh air.
Seek medical attention if respiratory irritation or discomfort persists.
Skin Contact:
Wash thoroughly with soap and water.
Remove contaminated clothing.
Seek medical attention if irritation develops.
Eye Contact:
Rinse immediately with plenty of clean water for at least 15 minutes.
Seek medical attention promptly.
Ingestion:
Do not induce vomiting.
Rinse mouth with water.
Seek immediate medical assistance.
Firefighting Measures of Monoaluminum Phosphate:
Suitable Extinguishing Media:
Use water spray, dry chemical, foam, or carbon dioxide (CO₂).
Specific Hazards:
Although Monoaluminium phosphate is non-flammable, thermal decomposition can generate irritating or toxic fumes, especially phosphorus oxides.
Protective Equipment:
Firefighters should wear self-contained breathing apparatus (SCBA) and full protective clothing due to the risk of hazardous combustion products.
Accidental Release Measures of Monoaluminum Phosphate:
Personal Precautions:
Use personal protective equipment (PPE):
Gloves, goggles, and a lab coat.
Avoid dust formation if solid, and contain spills if liquid.
Environmental Precautions:
Prevent entry into drains, sewers, or surface waters.
Cleanup Procedures:
For solids:
Sweep up and place in appropriate containers for disposal.
For liquids:
Absorb with inert materials (e.g., vermiculite or sand) and collect for proper disposal.
Clean spill area with water and mild detergent.
Exposure Controls / Personal Protective Equipment of Monoaluminum Phosphate:
Engineering Controls:
Ensure adequate ventilation, especially in confined or enclosed spaces.
Use fume hoods or local exhaust systems for laboratory work.
Personal Protective Equipment (PPE):
Respiratory protection:
Not required under normal conditions; if dust or mist is present, use a NIOSH-approved dust mask or respirator.
Eye protection:
Wear chemical safety goggles or face shields.
Skin protection:
Use nitrile or neoprene gloves, long-sleeved clothing, and protective footwear.
Hygiene Measures:
Wash hands before eating, drinking, or using the restroom.
Avoid eating or drinking in the working area.
Identifiers of Monoaluminum Phosphate:
CAS Number:
7784-30-7
22784-12-9 (trihydrate)
ChEMBL: ChEMBL3833315
ChemSpider: 58204
DrugBank: DB14517
ECHA InfoCard: 100.029.142
EC Number: 232-056-9
PubChem CID: 64655
RTECS number: TB6450000
UNII: F92V3S521O
UN number: 1760
CompTox Dashboard (EPA): DTXSID5064839
InChI:
InChI=1S/Al.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+3;/p-3 check
Key: ILRRQNADMUWWFW-UHFFFAOYSA-K check
InChI=1/Al.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+3;/p-3/rAlO4P/c2-6-3-1(4-6)5-6
Key: ILRRQNADMUWWFW-ITXURHEJAW
InChI=1/Al.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+3;/p-3
Key: ILRRQNADMUWWFW-DFZHHIFOAZ
SMILES:
O=P12O[Al](O1)O2
[Al+3].[O-]P([O-])([O-])=O
Chemical Name: Monoaluminium Phosphate
CAS Number: 13530-50-2
EC Number: 236-875-2
Molecular Formula: Al(H₂PO₄)₃
Molecular Weight: 299.95 g/mol
UN Number: Not classified as hazardous for transport (no UN number assigned)
PubChem CID: 17817852
InChI: InChI=1S/Al.3H3O4P/c;3*1-4(2,3)5/h;3*(H3,1,2,3,5)
SMILES: O=P(O)(O)O[Al](OP(=O)(O)O)OP(=O)(O)O
Chemical Formula: Al(H₂PO₄)₃
Molecular Weight: 299.95 g/mol
Appearance: White crystalline powder or viscous, clear to hazy solution
Odor: Odorless
pH (1% aqueous solution): ~1.5 – 2.5
Solubility in Water: Highly soluble (especially in acidic aqueous media)
Boiling Point: Not applicable (decomposes before boiling)
Melting Point: Decomposes upon heating (> 300°C, loses water and forms polyphosphates)
Density: Approx. 2.5 g/cm³ (for solid form)
Thermal Stability: Stable up to ~300°C; above that, condenses to form aluminum pyrophosphates
Refractive Index: Not applicable (typically measured for solution, varies with concentration)
Hygroscopicity: Hygroscopic in powder form
Flash Point: Not flammable
Conductivity: Conductive when in aqueous solution due to ionization
Properties of Monoaluminum Phosphate:
Chemical formula: AlPO4
Molar mass: 121.9529 g/mol
Appearance: White, crystalline powder
Density: 2.566 g/cm3, solid
Melting point: 1,800 °C (3,270 °F; 2,070 K)
Boiling point: Decomposes
Solubility in water: 1.89×10−9 g/100 ml
Solubility product (Ksp): 9.84×10−21
Solubility: Very slightly soluble in HCl and HNO3
Refractive index (nD): 1.546
Molecular Weight: 121.953
Hydrogen Bond Donor Count: 0
Hydrogen Bond Acceptor Count: 4
Rotatable Bond Count: 0
Exact Mass: 121.9349589
Monoisotopic Mass: 121.9349589
Topological Polar Surface Area: 86.2 Ų
Heavy Atom Count: 6
Complexity: 36.8
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: 2
Compound Is Canonicalized: Yes
Chemical Name: Monoaluminium Phosphate
Chemical Formula: Al(H₂PO₄)₃
Molecular Weight: 299.95 g/mol
Physical State: Solid (powder) or aqueous solution (viscous liquid)
Appearance (solid): White to off-white crystalline powder
Appearance (solution): Clear to hazy, viscous, colorless or slightly yellowish liquid
Odor: Odorless
Solubility: Freely soluble in water; insoluble in organic solvents
pH (1% aqueous solution): Approximately 1.5–2.5
Thermal Decomposition: Begins above 300°C, forming aluminum pyrophosphate and eventually aluminum metaphosphate
Melting Point: Decomposes before melting
Boiling Point (solution): Water component evaporates; Monoaluminium phosphate decomposes rather than boiling
Density (solid): ~2.5 g/cm³
Density (solution): ~1.45–1.60 g/cm³ (varies with concentration)
Viscosity (solution): Medium to high, depends on concentration and temperature
Hygroscopicity: Hygroscopic in powder form; absorbs moisture from air
Electrical Conductivity: Conductive in aqueous solution due to ionic dissociation
Flammability: Non-flammable
Reactivity: Reacts with bases, metal oxides, and alkalis; forms stable complexes with magnesium, zinc, etc.
Toxicity: Generally considered low toxicity; safe under standard handling conditions
Stability: Stable under acidic and dry storage; may polymerize in solution
Specifications of Monoaluminum Phosphate:
Appearance (Powder): White or off-white fine crystalline powder
Appearance (Solution): Clear to slightly hazy, viscous, colorless or pale yellow
Al₂O₃ Content (as % by weight): 9.0 – 11.5%
P₂O₅ Content (as % by weight): 43.0 – 46.0%
Free Phosphoric Acid (%): ≤ 2.0%
Insoluble Matter: ≤ 0.2%
pH (10% solution): 1.5 – 2.5
Specific Gravity (liquid): 1.40 – 1.60 g/cm³
Viscosity (25°C): 50 – 300 cP (varies by grade and concentration)
Loss on Drying: ≤ 25% (mainly water content in solution form)
Solubility in Water: Complete, forming a stable acidic solution
Heavy Metals (as Pb): < 10 ppm (depending on grade) Iron (Fe) Content: < 100 ppm Chloride Content (as Cl⁻): < 0.05% Storage Stability: Minimum 6–12 months in sealed containers Names of Monoaluminum Phosphate: Regulatory process names: Aluminium orthophosphate Aluminium orthophosphate aluminium orthophosphate Aluminium orthophosphate, natural Aluminiumphosphat Aluminophosphoric acid Aluminum acid phosphate Aluminum monophosphate Aluminum phosphate Aluminum phosphate (1:1) Aluphos FFB 32 Monoaluminum phosphate Phosphalugel Phosphoric acid, aluminum salt (1:1) CAS name: Phosphoric acid, aluminum salt (1:1) IUPAC names: [phosphato(3-) -kappa~3~O,O',O'']aluminum [phosphato(3-)-kappa~3~O,O',O'']aluminum Al-phosphat Aluminium monophosphate Aluminium orthophosphate aluminium orthophosphate Aluminium Orthophosphate Aluminium orthophosphate Aluminium ortphosphate Aluminium phosphate Aluminium Phosphate aluminium(3+) phosphate Trade names: PHOSPHINAL PZ04 Registration dossier Other names: Aluminum phosphate Aluminium monophosphate Phosphoric acid, aluminium salt (1:1) aluminum;phosphate MONOALUMINUM PHOSPHATE Phosphoric acid, aluminum salt (1:1) MeSH of Monoaluminum Phosphate: aluminum monophosphate aluminum phosphate aluminum phosphate (3:1) aluminum phosphate (3:2) aluminum phosphate dihydrate Phosphalugel