Silicates are key constituent of many construction materials. They serve as binders in paints, reinforce fire-resistant glass and are incorporated in concrete finishes. They are also used in drilling applications on mining and civil engineering projects, for soil stabilization and as adhesive systems.
Fire-resistant glass comprises a sandwich-type assembly of glass and silicate. The silicate solution, containing additives for enhanced flexibility, is allowed to dry on the surface of the glass. This is then enclosed in a steel frame.
In case of fire, the heat is absorbed by the silicate interlayers, which contain bound water. As the temperature rises, the water in the interlayers evaporates and the resulting glass foam expands to form an insulating barrier. When the top layer of glass shatters due to the excessive heat, the foamed water glass holds the fragments together.
When used as a binder in paints, potassium silicates will adhere to the mineral substrate by a process of silicification (chemical reaction between binder and substrate). This stabilizes the substrate and creates a durable chemical bond between substrate and coating.
Silicate treatments can be used to improve the properties of concrete surfaces. The greater abrasion and chemical resistance, in particular, will extend the service life of concrete floors.
The liquid silicate penetrates the surface and, upon reaction with the free calcium in the concrete, forms a calcium silicate hydrate gel that cures to a vitreous structure within the concrete pores. Lithium and composite lithium/potassium silicates are particularly suitable for this application.
In the course of civil engineering works, the ground is required to support heavy construction plant. The porosity and resulting water permeability of the soil increases its instability. To ensure safe working conditions, it thus requires appropriate treatment.
One proven method involves the use of sodium silicate as a stabilizing agent. The sodium silicate is injected into the ground together with a hardener to speed up the reaction. The required degree of soil stabilization and impermeability is achieved by varying the dilution level and hardener quantity.
Geopolymers are aqueous silicate solutions mixed with reactive mineral fillers. They are used in a wide variety of applications: as mineral adhesives, as mineral coatings, as binders in fibre composites and as a new type of cement, designed to replace concrete. One of the key benefits offered by geopolymers is their drying speed: depending on their composition, they can dry within minutes or only a few hours at room temperature. With a production-related carbon footprint far superior to that of standard Portland cements, geopolymers also offer an eco-efficient alternative.
We develop geopolymers that are precisely tailored to our customers' needs, specifically in terms of their physical and chemical properties. These properties then pave the way for the use of geopolymers as a substitute for organic polymers, ceramics or cements in many applications.
Sodium and potassium silicates are used for ground stabilization during drilling operations. Experts typically distinguish between three basic types of drilling fluid, based on their effectiveness in stabilizing the borehole wall, environmental compatibility and cost:
Systems based on natural or synthetic oils are now largely obsolete for both economic and ecological reasons. Compared to OBM systems, sodium and potassium silicates offer equivalent – and, in some applications, superior – stabilizing performance, even in loose rock strata. They also have the additional advantage of being ecologically harmless.
SILACOLL is one of the big success stories in the history of research at vanBaerle. The mineral-based SILACOLL adhesives are fireproof and heat-stable while also offering excellent wet adhesion.
They are used in the construction industry, e.g. to fix insulation board to walls and ceilings, and for the industrial production of fire-resistant elements.
Sodium and potassium silicates are used in the manufacture of fire-resistant vermiculite, perlite and exfoliated graphite insulation board.
The inert silicate is blended with the material and, if necessary, an additional hardener to form a homogeneous mass. The insulation mix is then pressed into shape in a mould and heat-cured.
The terms "anti-corrosion" or "corrosion-inhibiting" are used to describe measures taken to suppress or slow down the destruction of materials, usually metal, through the action of water and oxygen. Such measures are based on one of two fundamentally different methods:
1. Passive corrosion protection: The metal surface is protected from contact with water and oxygen, e.g. by means of a coated finish.
2. Active (cathodic) corrosion protection:The metal requiring protection is either coated by a less noble metal (i.e. a metal lower in the galvanic series) or connected to a "sacrificial anode". Although this does not prevent corrosion, it is only the "sacrificial metal" and not the protected metal that decomposes.
With silicate-bound zinc coatings, the two mechanisms operate in tandem, thus offering double protection.
For best results, ceramic production requires easily pourable slurries with a high solids content to ensure proper homogenization of the raw materials.
A further advantage of the wet process consists in the lower energy consumption for wet grinding in comparison to dry grinding. Silicate-based dispersants allow the achievement of higher concentrations while maintaining the ideal viscosity. It is also possible to make targeted adjustments to the rheological properties of the slurry.