Aluminum sulfate

Aluminum sulfate (CAS 10043-01-3), commonly known as alum, is an inorganic salt used primarily as a coagulant and flocculant.

Where is Aluminum sulfate used?

• Water and wastewater treatment: dosed into raw water to aggregate colloidal solids, turbidity and organic matter ahead of clarification
• In wastewater treatment, used to remove phosphates.
• Pulp and paper: rosin sizing, water resistance and fiber retention on the wire
• In waste paper processing, used as a flocculant to remove ink particles and other contaminants during recycling.
• Textile and leather processing: mordant and tanning auxiliary that fixes dyes and prepares hides
• Building and construction: set accelerator in concrete and cement formulations, reducing cure time
• Used in fire extinguishing systems.
• Aluminum Sulfate 50% is used as an oilfield and drilling fluid additive.
• It destabilizes suspended particles in water and process streams, enabling removal through settling or filtration.

Formulation notes

• Alternatives as a precipitant include iron(III) chloride, polyferric sulfate, or polyaluminum chloride (PAC).
• Reacts with bases.
• Reacts violently with strong oxidants, producing heat and toxic and corrosive fumes including sulfur oxides.
• Attacks many metals in the presence of water.

Typical specification

• Maximum iron (Fe) content is 0.02%.
• Minimum Al2O3 content is 17%.
• Solid aluminum sulfate has 0.08–0.10% water-insoluble matter.
• The assay as available water-soluble Al2O3 is minimum 8.0%.

Regulatory status

• Aluminum sulfate products are manufactured in accordance with TS EN 878 and TS 1867 standards.
• Aluminum sulfate is not subject to restriction under REACH.
• Aluminum sulfate is not classified as a substance of very high concern (SVHC).
• The product is suitable for use as a coagulant in drinking water treatment plants.

Storage, packaging and handling

• Commonly solid aluminum sulfate is also supplied in 1000 kg or 1200 kg big bags.
• Store aluminum sulfate separated from bases and strong oxidants, in a dry area without floor drains or sewer access.

Frequently asked questions about Aluminum sulfate

What is the pH of aluminum sulfate solutions?

The pH of the solution is between 1.4 and 2.6.

What grade and form is Aluminum Sulfate 50%?

Aluminum Sulfate 50% is supplied as a technical grade aqueous solution at 50% concentration.

Which standards and authorizations apply to aluminum sulfate for water treatment and food use?

DIN 19606 covers aluminum sulfate for water treatment, and it is authorized as food additive E 520 in the EU.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.