Aluminium sulfate
[CAS# 10043-01-3]

Identification

• Classification: API >> Special medicine >> Surgical medication
• Name: Aluminium sulfate
• Molecular Formula: Al₂^.(SO₄)₃
• Molecular Weight: 342.14
• CAS Registry Number: 10043-01-3
• EC Number: 233-135-0
• SMILES: [O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Al+3].[Al+3]

Properties

• Density: 2.71 g/mL (Expl.)
• Melting point: 770 ºC (decomp.) (Expl.)
• Water solubility: soluble Expl.)

Safety Data

• Hazard Symbols: GHS05 Danger
• Hazard Statements: H290-H318
• Precautionary Statements: P234-P264+P265-P280-P305+P354+P338-P317-P390-P406

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin corrosion	Skin Corr.	1A	H314
Oxidising solids	Ox. Sol.	2	H272

• Transport Information: UN 1760;UN 3077

Discovory and Applicatios

Aluminium sulfate is an inorganic compound with the formula Al₂(SO₄)₃. It is a widely used chemical substance with applications in water treatment, paper manufacturing, and various industrial processes. Aluminium sulfate is commonly encountered as a white crystalline solid, often in its hydrated form, and is highly soluble in water. It has been known and utilized for centuries, particularly for its coagulating properties in water purification.

The discovery and early use of aluminium sulfate date back to ancient times, particularly in dyeing and fabric treatment. It was historically employed as a mordant in textile dyeing, a role it still fulfills today. The compound's ability to help fix dyes onto fabrics made it a valuable substance in early textile production. Its large-scale production and industrial use expanded significantly in the 19th and 20th centuries with advancements in chemical manufacturing.

One of the most significant applications of aluminium sulfate is in water treatment. It serves as a coagulating agent in municipal and industrial water purification processes. When added to water, aluminium sulfate hydrolyzes to form aluminum hydroxide, which acts as a flocculant. This process helps aggregate fine particles and impurities, making them easier to remove through filtration or sedimentation. The use of aluminium sulfate in water treatment has been well-established as an effective means of improving water clarity and quality by reducing turbidity and removing suspended solids.

In the paper manufacturing industry, aluminium sulfate plays an essential role in the sizing process. It is used in conjunction with rosin to improve the paper’s resistance to water and ink penetration. By reacting with rosin, aluminium sulfate helps form a stable and uniform coating on paper fibers, enhancing printability and durability. This application has been a standard practice in the paper industry for many years.

Aluminium sulfate is also used in agriculture as a soil amendment. It can be applied to alter soil pH, particularly in cases where increased soil acidity is required. Gardeners and farmers use it to lower the pH of alkaline soils, creating a more favorable environment for acid-loving plants such as hydrangeas, blueberries, and azaleas. The reaction of aluminium sulfate with water releases hydrogen ions, which contribute to soil acidification.

Another well-established application of aluminium sulfate is in the production of deodorants and antiperspirants. In this context, it functions as an astringent, helping to reduce perspiration by constricting sweat gland openings. Although alternative compounds are now more commonly used, aluminium sulfate has been historically significant in this field.

In addition to these major applications, aluminium sulfate is used in fireproofing textiles, tanning leather, and as a component in certain pharmaceuticals. Its ability to react with proteins and other organic compounds makes it useful in diverse industrial processes.

The handling and storage of aluminium sulfate require caution due to its acidic nature. When dissolved in water, it forms a strongly acidic solution, which can cause irritation or corrosion to certain materials. Proper safety measures are necessary to avoid direct contact with skin and eyes. While aluminium sulfate is generally considered safe for its intended applications, excessive exposure or improper handling can pose health and environmental risks.

Aluminium sulfate remains an important industrial chemical with a long history of use. Its role in water treatment, paper manufacturing, agriculture, and other industries highlights its significance in modern applications. The compound’s well-documented effectiveness in coagulation, pH adjustment, and material treatment ensures its continued use in various sectors.

References

2024. Poria cocos polysaccharide-loaded Alum Pickering emulsion as vaccine adjuvant to enhance immune responses. Colloids and Surfaces B: Biointerfaces, 244.
DOI: 10.1016/j.colsurfb.2024.114144

2024. Green hybrid coagulants for water treatment: An innovative approach using alum and bentonite clay combined with eco-friendly plant materials for batch and column adsorption. Environmental Research, 259.
DOI: 10.1016/j.envres.2024.119569

2024. Removal of acephate and methamidophos from water: Coagulation and adsorptive treatment approaches. Environmental Pollution, 357.
DOI: 10.1016/j.envpol.2024.124514