What is the Production Process of Zircon Mullite Bricks?

Zirconia mullite brick is a refractory product made of mullite and zirconia. Zircon mullite fused cast brick has dense crystal structure, high softening temperature, good thermal stability, high mechanical strength, good wear resistance, good thermal conductivity and good corrosion resistance. Zircon brick series products are based on α-Al2O3, with partially stabilized zirconia and zirconia corundum clinker as raw materials. After mixing, molding, drying, and high-temperature firing in a shuttle kiln. Zirconium bricks have compact structure, high volume density and large capacity. High mechanical strength, good thermal shock stability, reheating shrinkage, low high temperature creep, high chemical stability, corrosion resistance to alkali medium.

Rongsheng Zircon Mullite Brick

Introduction to the Production Process of Zirconium Mullite Brick

By introducing ZrO2 into A12O3-SiO2 series bricks, the structure of mullite can be improved. It can improve the chemical resistance of mullite, and has the characteristics of thermal shock resistance and low expansion coefficient. The production of zirconium mullite bricks (http://www.aluminabricks.com/refractory-bric/zircon-fire-brick/zircon-mullite-bricks/) is generally produced by electric melting method and also by sintering method.

Sintered zirconia mullite brick is a special refractory material made of industrial alumina and zircon concentrate, and zirconia is introduced into the mullite matrix through a reaction sintering process. The introduction of zirconia into the phase transition toughness of mullite bricked zirconia can greatly improve the high temperature mechanical properties of mullite materials. Zirconia can promote the sintering of mullite materials, and the addition of ZrO2 can accelerate the generation of low melting point and the formation of vacancies in the dense sintering process of ZTM materials. When the mass fraction of ZrO2 is 30%, the relative theoretical density of the fired body at 1530°C reaches 98%, the strength reaches 378MPa, and the toughness reaches 4.3MPa·m1/2.

Zircon mullite bricks made of industrial alumina and zircon by reaction sintering are difficult to control due to simultaneous reaction and sintering. Usually, the firing temperature is 1450°C to make it dense. Then the temperature is raised to 1600°C for reaction, and ZrSiO4 is decomposed into ZrO2 and SiO2 at greater than 1535°C, among which SiO2 and Al2O3 react to produce mullite. Because the reaction produces mullite, a partial liquid phase appears when ZrSiO4 decomposes. The decomposition of ZrSiO4 can refine the particles and increase the specific surface area, thereby promoting sintering.

Studies have shown that when the amount of zircon added is less than 54.7%, the microstructure of the sintered sample gradually transitions from columnar corundum network to columnar mullite network structure with the increase of zircon content. The high-temperature flexural strength (1400°C) of the sample increases with the increase of zirconia content, a larger value appears when the zirconia content is 23.7%, and then the strength decreases. The addition of zircon helps improve thermal shock resistance.

Sintered Zirconia Mullite Brick

Sintered zircon mullite bricks (http://www.aluminabricks.com/refractory-bric/zircon-fire-brick/zircon-mullite-bricks/) are made of industrial alumina and zircon concentrates through a reaction sintering process. Sintered zircon mullite brick is a high-grade refractory brick made by introducing ZrO2 into the mullite matrix. There are two production processes for sintered zirconia mullite bricks. One is to complete the reaction sintering in the production process of refractory bricks to obtain a complete phase change microstructure. The second is a partial phase transition, maintaining an unbalanced combination. The two production processes have their own characteristics, and both can produce refractory bricks with excellent performance. In industrial production, in order to reduce the price of refractory bricks, high bauxite is often used instead of industrial alumina to produce zirconium-containing mullite bricks.

Rongsheng Zirconium Mullite Brick Manufacturer

Rongsheng refractory brick production and sales manufacturer is a powerful refractory brick manufacturer. Rongsheng's refractory brick products include not only zirconia mullite bricks, sintered zirconia mullite bricks, but also various high-grade refractory brick products. Refractory bricks can also be customized according to the actual production needs of customers. Contact us for free price and samples.