Characteristics of AZS bricks
| Subject/Level | AZS33-Y | AZS36-Y | AZS41-Y | |
|---|---|---|---|---|
| Chemical composition/% | Al2O3 | （Marja） | ||
| ZrO2 | 32.00~36.00 | 35.00~40.00 | 40.00~44.00 | |
| SiO2 ≤ | 16.00 | 14.00 | 13.00 | |
| Na2O ≤ | 1.45 | 1.45 | 1.30 | |
| (Fe2O3+TiO2+CaO+CaO+MgO+Na2O+K2O) ≤ | 2.00 | 2.00 | 2.00 | |
| （Fe2O3+TiO2） ≤ | 0.30 | 0.30 | 0.30 | |
| Bulk density (dense part) (g/cm³) ≥ | 3.75 | 3.80 | 3.95 | |
| Apparent porosity/% ≤ | 1.50 | 1.00 | 1.00 | |
| Erosion rate of antimole glass under static conditions (ordinary soda-lime glass , 1500 ℃ × 36h)/(mm/24h) ≤ | 1.60 | 1.50 | 1.30 | |
| Initial liquid phase precipitation temperature ℃ ≥ ≥ | 1400 | 1400 | 1400 | |
| Bubble release rate % (1300°C X 10 hours, plain soda-lime glass) ≤ | 2.00 | 1.50 | 1.00 | |
| Exudation of vitreous phase (1500 ℃×4 hours)/% ≤ | 2.00 | 3.00 | 3.00 | |
| Thermal expansion rate (room temperature ~1000 ℃)/% ≤ | Provide measured data | |||
| Bulk density /(kg/m3) | TP、QX ＞ | 3400 | 3450 | 3550 |
| ZWS ＞ | 3600 | 3700 | 3850 | |
| WS ＞ | 3700 | 3750 | 3900 | |
PRODUCT DESCRIPTION
Bacor refractories (bacor)Baddeleytocorundum refractories belong to the Al2O3 -ZrO2 - SiO2 system. The area of the most common compositions of bacor refractories, containing 30 to 42% ZrO2, is determined by the position of the ternary eutectic with a melting point of 1765℃.
Baddeleyite-corundum refractories, known as AZS electric smelting zirconia corundum brick, AZS brick, fused AZS brick. According to the Russian mark, baddeleyite-corundum refractories are divided into BK-33, BK-36, BK-41. According to the international mark, they are divided into AZS-33, AZS-36, AZS-41. Of these, 33, 36 and 41 are named according to their Al2O3 content. For example, AZS33 refers to fused zirconia corundum brick with alumina content of 33%.
Пproduction and Methods Рazlyva
Bacor refractories are produced by melting mixtures of technical alumina, zircon and baddeleyite in electric arc furnaces. The melt is poured into refractory molds, and after its solidification residual stresses are relieved by additional heat treatment.
Fig. 1 schematically shows the macrostructure of bacors at different variants of refractory block casting.
With normal filling (NC), shrinkage shells are formed at 1/3-1/2 of the thickness of the product. By means of a special arrangement of the sprue hole and the mold during casting, a lumber with oriented shrinkage shells (OS) is obtained. If a much larger volume is poured and the gutter and porous parts are subsequently trimmed on a machine with a diamond tool, blocks with a small shrinkage sink at the end (RC) or without shrinkage sinks (FS) are produced - solid-filled (high-density) blocks.
Fig. 1. Macrostructure of bacors at different pouring variants: NC - normal shrinkage shell; OC - oriented shell; RC - reduced shell; FC - without shrinkage shells
Premmuschestvo Baddeleyite-corundum refractory
AZS bricks have excellent high-temperature refractoriness and can withstand very high temperatures, typically up to 1500°C or more.
The corrosion resistance of bakor refractories increases with increasing ZrO2 content. Thus, increasing the amount of ZrO2 from 33% to 41% increases the corrosion resistance at cooking temperature by 1.3-1.5 times.
he zirconium and aluminum oxide in baddeleyite-corundum refractory is highly chemically stable. This means that it does not react or change in a wide range of chemical media, which ensures its long-term stability and reliability.
AZS bricks have good thermal shock resistance and are able to rise and fall rapidly at high temperatures without breaking down. This characteristic allows it to be used in processes requiring frequent temperature changes or exposure to sudden temperature fluctuations.
Application
Electro fused zirconia corundum brick is the second most used and most important type of brick for float glass kilns. In large-scale furnaces, it is mainly used in the melting section and pool wall, the breast wall of the melting section, the sidewalk bricks at the bottom of the pool, the entire small furnace and key parts of the heat storage room.
