BTC offers silicate solutions of alkali metals which are used in the paper and pulp industry for uses like
- stabilizers for pulp bleaching;
- additive for de-inking of recycled paper;
- adhesive for the production of cardboard and industrial paper board.
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.
Properties of our silicates for pulp and paper
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.
Sodium silicates are
- purely inorganic (inorganic silica-polymer solution);
- 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 the standard sodium silicates a special alkali silicate solution is available under the brand name Hyporan® for pulp and paper applications.
Applications of our silicates for pulp and paper
Sodium silicate solutions are used in the paper and pulp industry in a variety of ways providing
- peroxide stabilization,
- deflocculation (peptization),
Especially the bleaching process in pulp and paper is done nowadays with hydrogen peroxide whereas sodium silicates act as stabilizer. Sodium silicates with a low molecular ratio like Hyporan® for example provide additional alkalinity compared to standard sodium silicate solutions. The following advantages are offered:
- no additional need for caustic soda (NaOH);
- less flocculation tendency of silicate anions;
- better whiteness of paper;
- better fibre swelling.
In the production of cardboards or industrial paper products, sodium silicate is used as an
- additive for de-inking of recycled paper.
Further products used in combination with our silicates
Explore also our
- Complexing agents > for bleach stabilisation in the pulp industry
- Surfactants > as defoaming agents
- Dispersing agents > for stabilisation of dispersions in industrial applications
- Additives > for rheology modification and thickening
- Pigments and dyes > for speciality colouration in paper and board
- Aqueous dispersions (Latex) > for technical applications
BTC Europe is BASF's European sales organization for small and medium-sized customers focused on specialty chemicals. Our silicates are used in a variety of industries as
- anorganic binders and additives
- for corrosion inhibition in water systems (pipes)
- as flame retardant
- as stabilizers
- as binder for coatings for mineral surfaces