The micro-structure of fused cast AZS block has a big effect on the properties and performance of fused cast AZS block. The main crystal phase of fused cast AZS consists of corundum, baddeleyite and glass phase.

Generally, corundum and baddeleyite exist in eutectic crystals, which contribute greatly to the stable structure of fused cast AZS block. Some products may contain mullite which has bad effect on the performance of AZS. With the presence of mullite in the boundary of ZrO2 crystals, glass phase caot fully absorb the stress caused by the volume expansion due to crystalline transformation, which may result in cracks.

After the fused cast AZS molten is cast into the mold, it must be subjected to thermal aealing to make the molten crystallized slowly. Since the sidewall and the central region are cooling at different speed, the surface is cooling faster and first forms a layer with uniform fine grain structure, which is called dense layer. The chemical composition of the dense layer is substantially the chemical composition of the original design and the main crystal phase is C+Z.

Along the sidewall to the center of the mold, the cooling speed gradually slows and forms the slow cooling layer. Baddeleyite first separates out in the form of primary crystals and is precipitated and enriched by gravity to form the zirconia-rich layer. Finally as the residual liquid phase of the melt is concentrated, it separates out as stacked and oriented eutectic crystals. Thus, along the solidification temperature gradient, different layers have different chemical composition and phase composition, resulting in segregation of the main phase. The higher the ZrO2 content, the larger the size, the more remarkable the segregation.

Although the chemical compositions of fused cast AZS from different manufacturers are similar, the micro-structure can be quite different. The differences between the micro-structures of AZS are mainly owed to the cooling and aealing rate. Lower cooling and aealing rate will cause the enrichment or separation of minerals in some regions and the decrease of corundum and baddeleyite eutectic crystals. Therefore, an appropriate increase in cooling and aealing rate is the key to obtain fused cast AZS blocks with even component distribution, reasonable crystal size and excellent performance.

In the fused cast AZS, ZrO2 has the best corrosion resistance. The increase of ZrO2 content can improve the corrosion resistance. However, the increase of the corrosion resistance is not proportional to the content of ZrO2, as it will increase the difficulty of manufacturing and has a bad effect on the performance of fused cast AZS.

Zhengzhou Sunrise is a refractory material supplier from China, offering high quality refractory materials for glass fuaces, including fused cast AZS block, fused cast alumina block, fused cast high zirconia block, mullite brick, zircon brick, alumina bubble brick, magnesia brick, sillimanite brick, corundum brick, low porosity fireclay brick, high alumina brick, all kinds of glass fuace ramming masses, etc..

Refractories are the main materials used in the glass fuaces and have big influence on the service life of glass fuaces, the quality of glass, the energy consumption and the cost. The development of the manufacturing technology of glass greatly depends on the the development of refractory technology and improvement of the quality of refractories.

Glass is melt at more than 1600℃, so the refractories will suffer from corrosion during the manufacturing process. The corrosion resistance performance and corrosion rate of refractories determines the service life of glass fuaces. The larger the scale of glass fuaces is, the bigger the production capacity is. The quality and accuracy of refractories has direct influence on the scale of glass fuaces. The application of the oxygen-fuel technology and reduced pressure technology depends on the performance of refractories, since those technologies increase the concentration of alkali vapor and water vapor, make the refractories more serious and have more demanding performance on the performance of refractories. Since the corrosion of refractories can also cause glass defects such as stones, bubbles and stripes, the corrosion resistance performance has a big influence on the quality of glass.

According to the types of glass produced, the size and structure of fuaces, the quality of glass required and the production capacity, different refractories are selected. So far, refractories for the glass industry, especially the float glass fuaces, include fused cast refractories, silica bricks and magnesia refractories.

Fused Cast Refractories

Fused cast refractories are refractories made by melting the raw materials and then casting the melt into a mold. Fused cast refractories for glass fuaces mainly include fused cast AZS, fused cast alumina block and fused cast high zirconia block. Fused cast AZS and fused cast alumina block are the main refractories used in float glass fuaces, Electronic glass fuaces, household glass fuaces, and pharmaceutical glass fuaces. Besides glass contact areas, they are also used in demanding areas such as the beast wall and the crown.

Silica brick

Silica brick is a traditional refractory used in glass fuaces, especially in the crown and superstructure. The quality of glass fuaces will affect the normal operation and service life of glass fuaces.

Magnesia refractories

Magnesia refractories are alkali refractories, including fused cast magnesia brick, high pure magnesia brick, direct bonded magnesia chrome brick and magnesia zircon brick. Magnesia refractories are mainly used in the regenerator.

Zhengzhou Sunrise is a refractory material supplier from China, offering high quality refractory materials for glass fuaces, including fused cast AZS block, fused cast alumina block, fused cast high zirconia block, mullite brick, zircon brick, alumina bubble brick, magnesia brick, sillimanite brick, corundum brick, low porosity fireclay brick, high alumina brick, all kinds of glass fuace ramming masses, etc..