Silicates > as corrosion inhibitor for metals or for water pipes

BTC offers silicate solutions of alkali metals which act as corrosion inhibitors in formulations to prevent alkaline attack on sensitive glazed dishware, glass or metallic surfaces. Liquid silicate solutions are also used as corrosion inhibitor for water pipes.

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.

Brands

Sodium Silicate

Potassium Silicate

Properties of our silicates for corrosion inhibition in water systems (pipes)

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.

Applications of our silicates for corrosion inhibition in water systems (pipes)

Soluble silicates are used as corrosion inhibitors because of several effects:

  • formation of physical barrier;
  • formation of protective monomolecular layer on metal surfaces;
  • increasement of pH value which makes metals less sensitive against corrosion;
  • complexing of metal ions.

To achieve the inhibiton effects, sodium silicates with a SiO2 content of 25%-30% are mainly used. The required concentration of SiO2 is provided by a sodium silicate solution with a molecular ratio between 2 and 3, for example sodium silicate 37/40 or sodium silicate 40/42 beside others. Potassium silicates offer an alternative if sodium is not tolerable.

Further products used in combination with our silicates

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About BTC

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

besides others.