News

How boron enhances ceramic glazes

:: Thursday, July 10, 2025 :: Posted By Maryam Moravej

The ceramics industry is changing fast and so are the pressures facing manufacturers. Glaze formulations today are expected to:

  • Withstand faster firing cycles at higher temperatures
  • Meet tighter emissions and health regulations
  • Satisfy evolving global quality standards

As a result, traditional materials such as lead and high-alkali oxides are seeing greater scrutiny due to toxicity and durability concerns.

In their place, refined borates such as boric oxide (B2O3) and anhydrous borax are helping whiteware ceramics manufacturers achieve better glaze results more efficiently.

Boron’s impact on glaze behavior

Boron oxide is a key fluxing oxide in ceramic glazes. It helps lower melting temperatures, stabilizes other oxides, and improves flow behavior. Using boron oxide in your frits helps:

  • Reduce melting points, saving energy
  • Achieve better glass clarity and homogeneity
  • Fine-tune thermal expansion, minimizing glaze stress
  • Improve chemical durability, especially for demanding end-use environments

Boron acts as both a network former and modifier in the glassy phase of ceramic glazes. As a network former, boric oxide can replace a portion of the silica that typically forms the backbone of the glass structure (most of which comes from the frit).

Unlike silica, which requires very high temperatures to melt, boron lowers the melting point, allowing glass to form more easily while saving energy.

As a network modifier, boron disrupts the silica structure, reducing the rigidity of the glass network. This lowers viscosity and improves melt flow, which is a major advantage during fast firing cycles where there’s less time for the glaze to fully mature and flow properly. A lower-viscosity melt ensures the glaze can form a smooth, even layer before cooling starts.

This dual-role—reinforcing the glaze structure while also enhancing its processing characteristics—makes boron especially effective for balancing melting behavior, thermal expansion on the substrate, and long-term chemical durability.

Choose the right borate product for your glaze

Correct borate use remains a key factor in optimal frit performance. When choosing a borate product, consider:

  • Processing conditions of the final ceramic articles
  • Composition of the final glaze and requirements for secondary oxides such as sodium and calcium
  • Cost and availability of borates

It’s important to use a refined product such as Neobor® or Dehybor®, to avoid defects and ensure you get consistent results.

Using unrefined borates can increase the likelihood of pinholing, crazing, color pigmentation issues, surface defects, and introduction of toxic heavy metals such as arsenic. These issues are costly and can cause irreparable damage to your organization’s reputation.

Anhydrous advantage

As you evaluate your ceramic process, it’s important to know that anhydrous borates offer performance advantages across your production.

Higher boric oxide content
Anhydrous borates create more efficient fluxes due to higher boron content, which helps lower glaze melting points without compromising quality.

No water of hydration
Eliminating the chemically bound water provides greater formulation stability, reduces batch variability, and lowers furnace emissions.

Smoother, glossier finishes
Glazes using anhydrous borates typically see improved flow, gloss, and uniformity thanks to better melt behavior.

More reliable performance
Greater control over firing behavior reduces the risk of pinholing, crazing, and blistering.

For these reasons, many glaze manufacturers prefer Dehybor, an anhydrous borate product from U.S. Borax. In addition to production benefits, Dehybor features a higher bulk density, which can lower shipping costs.

Download Dehybor's product data sheet

Need help with your ceramic glaze formulation? Let’s talk.

If you’re considering a change to your glaze process, contact our technical team. We can help you fine-tune your glaze formulation with a borate product that’s tailored to your unique needs and firing environment.

 

Resources

U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 650 customers with more than 1,800 delivery locations globally. We supply around 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles northeast of Los Angeles.  Learn more about Rio Tinto.

Copyright © 2025 Rio Tinto. All Rights Reserved.
Terms and conditions Privacy and cookies Modern slavery statement
AB 1305 Cookie preferences