Zircon-Mullite Bricks Introduction
Zircon-Mullite Bricks for glass furnace is a white solid formed by pure alumina powder and zircon sand containing zirconia 65% and about 34% silica in the electric furnace and then injected into the mold to be cooled. The AZS bricks structure consists of an eutectoid and a glass phase of corundum and zirconium, AZS fused cast bricks are phased as eutectoids of the corundum phase and the zircon oblique phase, the glass phase is filled between their crystals.
Zircon-Mullite Bricks Application
Refractory zircon mullite brick is melted and casted in high temperature electric furnace by high quality mullite grops,AZS refractories brick is mainly used in areas that require good wear-resistance and high temperature resistance,such as gliding rail bricks in steel pusher metallurgical furnaces,the tapping platform(tapping spout)for tapping platform (tapping spout)style walking beam metallurgical furnaces,azs bricks also as the interior lining for destructors.
Zircon-Mullite Bricks Specification
| Al203 |
73% |
| Zro2 |
5.5% |
| SiO2 |
19% |
| Na2O |
1% |
| Corundum |
38% |
| Baddeleyite |
5% |
| Mullite |
40% |
| Vitreous Phase |
17% |
| True specific Gravity |
3.54g/cm3 |
| Cold Crushing Strength |
350Mpa |
| RefractorinessUnder Load of 0.2Mpa |
1700℃ |
| Thermal Expansion Rate |
0.8% |
| Thermal Conductivity |
4.6W/m.K |
| Apparent Porosity |
≤8% |
Zircon-Mullite Bricks Using Precautions in Glass Kiln
1.Irregular Changes in Thermal Expansion
The expansion curve of the zircon mullite firebrick has an anomaly near 1000 °C, the internal ZrO2 crystal undergoes a reversible crystal transformation with a large volume change. Therefore, AZS block product containing ZrO2 should not be used at around 1000 °C, the temperature is often A region that fluctuates sharply. When baking the kiln, the temperature change at 900~1150 °C should not be too large, generally can not exceed 15 °C / h, requiring a steady temperature rise. AZS fused cast bricks parts should be protected from blowing cold air and protected by other bricks to prevent cracking.
2.Shrinkage
When casting, there are often shrinkage holes in the casting mouth, and azs refractory brick body has more pores and poor density. Therefore, when the glass wall of the glass melting part is made, the shrinkage holes are directed toward the direction of the kiln. When AZS refractory brick is eroded to a very thin level, azs brick will cause a leakage of glass liquid. When used in the upper flame space of the kiln, the service life is very long, and there is no problem of running glass. Therefore, the casting port is used outwards to extend the service life.
3.Eutectic
The refractory zircon mullite brick and the clay brick are in contact with the clay brick. The eutectic phenomenon occurs at a high temperature of 1300 °C. Therefore, when the refractory material is selected, the two refractory materials with severe eutectic phenomena should be avoided from contact with the masonry, such as silica brick casting. Below AZS fused cast bricks ,AZS brick is most susceptible to erosion by the fused cast AZS brick.
Zircon-Mullite Bricks Packing & Delivery
Consider various and complex transportation conditions,all fused cast azs bricks products are packing following the highest standards with foam boards between every two blocks, corners protected with triangular hard card boards by steel bands and wrapping in plastic film on the outside.
For easy location of different materials,zircon mullite refractory bricks packing lists are places both inside and outside packages, and shipping marks are clearly painted on all cases.
