What Is Potassium Silicate Used For

Bisley InternationalFAQs

Potassium silicate is an inorganic compound composed of potassium, silicon and oxygen. It presents itself as either a white solid or colourless liquid and is alkaline, with a PH of 11.3. Potassium silicates have many uses, including as a concrete densifier, plant fertiliser and corrosion inhibitor. It’s also used as a fire retardant in wooden houses. Bisley International stocks and sells potassium silicates. We’ll look at a few of the uses for this versatile compound below.

Xeolith® LS250 Potassium Lithium Silicate

Building Industry

In the building industry, potassium silicate is primarily used as a concrete densifier. It has excellent sealing properties and gives the surface good sheen and anti-abrasive properties. The silicate works by combining with free limes to strengthen the concrete and seal the pores.

Mortars also make use of this versatile compound. Mortars containing potassium silicate show higher resistance to acidic environments and withstand hotter temperatures. Their application is also more straightforward, as these mortars have more body and don’t stick to the trowel.

Potassium silicate also finds use as a base for paints. The silicate binds to masonry in the same way as it does when used as a densifier. Using potassium silicate in paints gives a waterproof, washable and fire retardant coating to the surface. Zinc-rich, anti-corrosion coatings also make use of the properties of this compound.

Wood coatings for wooden houses also contain this compound as a binding and fire-retarding agent.


Plants need both potassium and silica to aid their growth. The silica acts as the building blocks for the plant’s stem and roots. The potassium acts as both an insecticide and a fungicide. The compound also aids in combating heat and water stress in plants during dry seasons. It can be administered either as a spray or added to the growth medium. Growers of cannabis even report higher THC levels when using potassium silicate. It works well as a nutrient booster, especially with hydroponic systems.

Other Uses in Industry

Welding rods use potassium silicate as a binder and flux. It’s advantageous in low hydrogen and stainless steel rods but is also used for mild steel welding. These rods produce a steady, hot arc at lower voltages without spluttering.

Soaps and detergents use potassium silicate to prolong shelf life and improve their cleaning and wetting ability. The silicate also acts as a corrosion preventative for metal surfaces. Oil and gas drilling use it as an alternative to oil-based drilling fluids since it’s considered environmentally safe.


Although best known as a concrete densifier, potassium silicate has many uses over varied industries. This compound is found in paints, detergents, fertilisers and welding rods. The excellent binding properties and heat resistance make this compound suitable for many applications.

In many of its uses, potassium acts as a transport agent for silica. Still, in others, potassium also plays an important role. Horticultural applications can’t make use of lithium or sodium silicates. They’re toxic to plants. Still, potassium acts as a fungicide for the plant as the silica helps it to grow.