Aluminium silicate, also known as kaolin, has several major and common uses, including:
- Ceramics and Refractory Materials: Aluminium silicate is widely used in the production of ceramics and refractory materials due to its high temperature resistance, low thermal expansion, and good mechanical properties. It is used to make high-quality porcelain, fine china, and other ceramics that are durable and have a smooth finish. In refractory materials, it is used as a component in firebrick, insulation, and castables.
- Paints, Coatings, and Pigments: Aluminium silicate is used as a filler and extender in paints, coatings, and pigments to improve their properties such as opacity, brightness, and resistance to wear and tear. It is also used as a flatting agent to reduce gloss in coatings.
- Plastics: Aluminium silicate is used as a filler in plastics to improve their mechanical properties such as stiffness, strength, and dimensional stability. It is also used as a flame retardant to reduce the flammability of plastics.
- Paper: Aluminium silicate is used as a filler in paper to increase its brightness, opacity, and printability. It also improves the paper’s surface smoothness and reduces ink absorption.
- Personal Care Products: Aluminium silicate is used as an ingredient in personal care products such as cosmetics, soaps, and toothpaste. It acts as a thickener, opacifying agent, and abrasive.
- Pharmaceuticals: Aluminium silicate is used as an inactive ingredient in some pharmaceuticals such as tablets and capsules. It is used as a diluent or filler to improve the flowability and compressibility of the active ingredient.
Overall, aluminium silicate has a wide range of industrial applications due to its unique properties and versatility.