Crystal clear: the role of potassium carbonate in glass manufacturing

Glass is an unmissable part of our daily lives. From reading glasses, windowpanes, and mirrors to smartphone screens, artwork, and tableware, glass can be found throughout our homes. Glass is also indispensable for industry and science. To give a few examples: high-temperature glass walled furnaces, microscopic and telescopic lenses, test tubes, and so much more.

With so many different applications, it’s not a surprise that there are many different types of glass, each with slightly different properties but all offering the functionality and beauty that we expect. Potassium carbonate from Vynova plays a vital role in many different glass applications, increasing the resistance, transparency, and refractive coefficient of glass to give it excellent clarity.

What is glass made from?

The most basic form of glass consists of a mixture of sodium silicate, calcium silicate, and silica. However, this form isn’t suitable for the majority of uses that we encounter daily. Elements that are commonly added to glass include bleaching powder, oxides of alkaline metals, calcium oxide (lime), and potassium carbonate. In fact, thousands of different chemical compositions can be used to make glass, each affecting the mechanical, electrical, chemical, optical, and thermal properties of the glass that is produced, making it suitable for different uses.

Glass usually contains formers, fluxes, and stabilizers.

  • Formers: the largest part of the glass mixture. This is often silica, or sand.

  • Fluxes: lower the temperature at which the formers will melt. Potassium carbonate, which is produced at the Vynova sites in Tessenderlo (Belgium) and Thann (France), is a common flux.

  • Stabilizers: ensure the glass is strong and water resistant. As the formers and fluxes are water soluble, a stabilizer is necessary so the glass doesn’t dissolve due to water or humidity.

Glass is manufactured by transforming these elements into a fine micro powder, which is fused then melted in a furnace. Depending on the type of glass required, the composition of the glass mixture, the temperature of the furnace and the finishing process can all vary.

Potassium carbonate in glass

Vynova is a preferred partner of the glass industry. We supply several grades of potassium carbonate for a wide range of glass manufacturing applications. Potassium carbonate (K2CO3) is produced by carbonating potassium hydroxide (KOH) with CO2.

Potassium carbonate is primarily used as a flux in glass production. It increases the resistance, transparency, and refractive coefficient of glass to give it excellent clarity, making it ideal for use in spectacles, glassware, television screens and computer monitors. And it looks stunning when used in glass sculptures and other artworks.

Potassium carbonate is an essential ingredient for various specific types of glass and is used to lend them some unique properties:

  • Potash glass is a hard glass that is made with potassium carbonate, calcium carbonate, and silica. It can withstand higher temperatures and is more resistant to the actions of acids. It is used in hard glass laboratory apparatus as well as in glass utensils.

  • In Pyrex glass, potassium carbonate is used to give the glass its high heat resistance. This heat-resistant glass, also known as borosilicate glass, is made from sodium carbonate, potassium carbonate, silica, borax, and aluminium oxide. Thanks to its heat resistant qualities, Pyrex glass is ideal for high-temperature laboratory equipment as well as domestic ovenware.

  • Optical glass thanks its high refractive index to potassium carbonate. This type of glass requires a careful manufacturing process to remain free of strains or other defects. This ensures the resulting glass has a high refractive index which is useful in eyeglasses, cameras, microscopes, telescopes, and other optical instruments.

  • In lead crystal glass, which is used for expensive glassware and decorative objects, the glass’s sparkle and exceptional transparency comes from its mixture of potassium carbonate, lead oxide and silica.

  • Potassium carbonate is also used for the production of strengthened glass, lending it exceptional durability, strength and properties that allow it to be used in extreme conditions, for example in airplanes.



Contact Vynova

Vynova is a leading European supplier of potassium derivatives with manufacturing sites in Belgium and France. Our potassium derivatives are used in numerous applications that benefit health and improve our quality of life – like potassium derivatives used in glass. Find out more about potassium derivatives from Vynova or contact one of our sales representatives here.



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