Product Description of Fused AZS Bricks For Glass Furnace Crowns
Fused zirconia corundum bricks are not only used in high-temperature and severely corroded areas that come into contact with molten glass but are also widely applied in the upper structures of glass furnaces.
Fused zirconia corundum bricks, also known as AZS bricks, are named based on the ternary phase diagram of Al₂O₃-ZrO₂-SiO₂. The chemical components are listed in order of their content: Al₂O₃ is represented by "A," ZrO₂ by "Z," and SiO₂ by "S." The standard abbreviations use this format, such as AZS-33# for 33-grade fused zirconia corundum bricks, AZS-36# for 36-grade, and AZS-41# for 41-grade.
Fused zirconia corundum bricks are formed by melting pure alumina powder and zircon sand, which contains approximately 65% zirconia and 34% silica, in an electric furnace. The molten material is poured into molds and cooled into solid white blocks. Their mineral structure consists of an eutectic composed of corundum and baddeleyite along with a glass phase. From a phase composition perspective, they are a eutectic of corundum and baddeleyite phases, with the glass phase filling the spaces between the crystals.
Fused zirconia corundum bricks are made by fully melting the raw materials, pouring them into molds, and allowing them to cool and solidify. The shrinkage cavities caused by volume contraction during solidification are critical considerations for their use. The casting methods for these bricks include standard casting, tilted casting, shrinkage-free casting, and quasi-shrinkage-free casting.
| Code | Name | Characteristics And Applications |
| PT | Standard Casting | Standard casting method, with shrinkage cavities located at the bottom. Mostly used for the upper structures of tank furnaces and other non-critical positions. |
| QX | Tilted Casting | Uses a tilted casting method, with shrinkage cavities located on one side. Mainly used for tank wall bricks. |
| WS | Shrinkage-Free Casting | Eliminates shrinkage cavities through precise casting to produce shrinkage-free products. Primarily used for critical positions like kiln roofs, tank walls, and areas subject to severe erosion. |
| ZWS | Quasi-Shrinkage-Free Casting | Similar to shrinkage-free casting, effectively reduces shrinkage cavities. Mainly used for tank wall bricks. |
