Kaolin

Kaolin (CAS 1332-58-7), also known commercially as Bolus alba, is a naturally occurring hydrated aluminum silicate clay mineral processed for industrial use.

Where is Kaolin used?

• Pulp and paper: coating pigment and filler improving printability, brightness and surface smoothness
• Rubber: reinforcing filler in tire sidewalls and molded goods
• Personal care: absorbent and texture-modifying agent in face masks, dry shampoos and pressed powders
• Construction materials: functional extender in paints and ceramic bodies
• In cement-based products it controls viscosity and reduces raw material costs.
• In ceramic industry.
• In adhesives, sealants and mastics.
• In glass fiber batches, used as an Al2O3 source; lowers the melting temperature of the glass and prevents crystallization of the glass.

Good to know: Calcined forms offer higher brightness for coatings. USP and BP-compliant grades serve pharmaceutical and cosmetic applications.

Formulation notes

• In paints, calcined kaolin can reduce TiO2 usage by up to 20%.

Typical specification

• Mohs hardness of 2.
• Moisture content ≤ 1%.
• Calcined kaolin has a purity of 92–93%.

Regulatory status

• Permitted for use in organic farming.

Storage, packaging and handling

• Calcined kaolin should be stored in cool and dry environments.
• Calcined kaolin must be protected from moisture.
• Calcined kaolin should be kept closed in its original packaging.

Frequently asked questions about Kaolin

What are the main uses of kaolin in glass fiber production?

Kaolin is used in the production of glass fiber, which is used in automotive, boat, sports equipment, aviation and space industries.

Is kaolin suitable for filtration processes?

Kaolin is an essential auxiliary in filtration processes.

How does kaolin behave at high solids content?

Kaolin has low viscosity at high solids content.

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