How to reduce the firing temperature of ceramics by using sodium feldspar?

In the ceramic manufacturing process, high-temperature firing has always been the main factor affecting energy consumption and production costs. In recent years, researchers have found that by introducing sodium feldspar (NaAlSi₃O₈) as a flux, the firing temperature of ceramics can be significantly reduced, thereby reducing energy consumption and improving production efficiency. This technology has been applied in many ceramic companies and has achieved significant economic and environmental benefits.

Fluxing mechanism of sodium feldspar

Sodium Feldspar is a common silicate mineral, widely found in granite and pegmatite. Its chemical composition is mainly sodium oxide (Na₂O), aluminum oxide (Al₂O₃) and silicon dioxide (SiO₂), and it has a low melting point (about 1100°C). During the firing process of ceramics, sodium feldspar can reduce the firing temperature through the following mechanisms:

Forming a low eutectic system: Na₂O in sodium feldspar acts as a strong flux, which can react with SiO₂ and Al₂O₃ in the ceramic body to form a low eutectic glass phase. This glass phase can soften and fill the gaps between the particles of the body at a lower temperature, promoting densification.

Accelerating liquid phase sintering: sodium feldspar decomposes at high temperature and generates a liquid phase, accelerating the particle rearrangement and diffusion process, thereby reducing the temperature required to achieve complete sintering.

Optimize microstructure: The addition of sodium feldspar can improve the microstructure of the ceramic body, reduce porosity and enhance mechanical strength.

Data support: experimental results and industrial applications

To verify the actual effect of sodium feldspar, several ceramic research institutions and enterprises have carried out experiments and production tests. Here are some key data:

Laboratory data: An experiment by the Shanghai Institute of Silicates, Chinese Academy of Sciences, showed that after adding 8% sodium feldspar to the daily ceramic formula, the firing temperature dropped from 1280°C to 1180°C, and the sintering time was shortened by about 15%. The water absorption rate of the final product remained below 0.5%, meeting the standards of high-quality porcelain.

Industrial verification: A ceramic company in Jingdezhen introduced 10% sodium feldspar in its bone porcelain production line, and the firing temperature dropped from 1320°C to 1220°C, and the energy consumption per unit product was reduced by about 12%, saving about 5,000 cubic meters of natural gas each year. This not only reduces production costs, but also reduces carbon dioxide emissions by about 30 tons.

Performance improvement: A ceramic company in Guangdong optimized the ratio of sodium feldspar to kaolin (sodium feldspar accounts for 6%), and the compressive strength of ceramic tiles fired at 1150°C reached 60 MPa, and the thermal shock stability was improved by 20%, making it suitable for high-end building applications.

These data show that sodium feldspar can not only effectively reduce the firing temperature, but also achieve energy conservation and emission reduction while ensuring product quality.

Technical advantages and challenges

The application of sodium feldspar brings multiple advantages to the ceramic industry. First, lowering the firing temperature directly reduces fuel consumption and greenhouse gas emissions, which is in line with the global carbon neutrality goal. Second, sodium feldspar is relatively cheap and widely available, which can effectively control production costs. In addition, the optimized sintering process can also shorten the production cycle and improve the competitiveness of enterprises.

However, the application of sodium feldspar also faces some challenges. For example, excessive addition may cause deformation of the green body or increase in bubbles, affecting the appearance and performance of the product. In addition, the chemical composition of sodium feldspar varies depending on the origin, and strict raw material screening and formula adjustment are required to ensure stability.

Conclusion

As a high-quality sodium feldspar supplier, Henan Ankai New Materials Co., Ltd. continues to provide high-performance raw materials for the ceramic industry, helping enterprises achieve low-temperature firing, energy saving and consumption reduction. In the future, with the continuous advancement of technology, sodium feldspar will play a greater role in the green manufacturing of ceramics, and Ankai New Materials will continue to serve the development of the industry with high-quality products.