Silicates as inorganic binders and additives

BTC Europe offers silicate solutions of alkali metals as inorganic binders or formulation additives for the use in versatile industries. Silicates are also known as water glass or liquid glass. Silicate solutions of alkali metals are known mainly as sodium silicate or potassium silicate. Mainly alkali silicates provide alkalinity beside other properties like adhesion (binding) or stabilisation. The silicate composition and the used alkali metal (sodium, potassium or others) determine the final property of the silicate.

Alkali silicates are often as

• binders for construction formulations;
• deflocculants for slurries (ceramic slurries);

Properties of our silicates (water glass)

Alkali silicates are characterized by their weight ratio of xSiO2:yAlk2O (silica:alkali-metal ratio), which is often documented as molar ratio, or water glass modul. The final BTC silicate products depend on the alkali silicate lumps as base material and the further processing to get the final aqueous silicate solution.

Depending on the used molar weight and water content the silicate solutions are different in viscosity, density and pH-value. Generally all silicates are considered as alkaline (pH >9) solutions. With increasing alkali metal content the pH value increases and the adhesion and binding properties are also enhanced.

Potassium silicates differ in the following properties from sodium silicates:

• they provide less tackiness;
• no-efflorescence occurs;
• they show good solubility;
• they offer high temperature binding properties.

However sodium silicates solutions are economically more attractive if not specific properties like flame colour or no-efflorescence is needed.

Both, aqueous potassium and sodium silicates, are

• purely inorganic (inorganic silica-polymer solution);
• non-combustible;
• VOC-free;
• Odourless;
• UV-light, thermal and chemical resistant;
• non-toxicological (they show no allergenic or mutagenic potential);
• food-contact approved;
• free of preservatives.

Silicate solutions are sustainable products and thus they are used in many versatile applications.

Despite standard grades like potassium or sodium silicates special alkali silicate solutions are available under the brand names Grossil®, Nuclesil® and Trasol®. These grades differ besides the silica-alkali metal ratio also in terms of purity (less metal content), viscosity and transparency for certain applications.

Portil® is a solid silicate grade produced by a spray drying process. It has an amorphous structure and is easily soluble in case it has to be dissolved again in water.   

Applications of our silicates used as inorganic binders and additives

Soluble silicates are reactive raw materials. In almost all applications and uses, liquid silicates are finally converted into a solid silicate which is reversible unless an acidification occurs. The latter leads to a gelling or hardening with an irreversible character.

BTC’s potassium or sodium silicates and the grades Grossil®, Nuclesil® and Trasol® Portil®  are used as

• binders for silicate paints, e.g. protective & decorating coatings on mineral surfaces
• deflocculants for slurries (ceramic slurries);
• nano ceramic coating (Sol-Gel processing)"