What is High Zirconia Bricks？

High Zirconia Bricks

1.Has a high resistance to acids, alkalis and glass liquids

2.Used for contact with molten glass

3.Used in the upper structure of glass melting furnaces

High Zirconia Bricks Introduction

High Zirconia 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, refractory zirconia bricks are phased as eutectoids of the corundum phase and the zircon oblique phase, the glass phase is filled between their crystals.

High Zirconia Bricks Application

High Zirconia bricks has excellent corrosion resistance and very low blister and stoning potential. AZS refractory bricks has no contamination to molten glass nearly .The fused cast AZS bricks produce can be mainly used in sidewalls,throats, electrodes and dam of various glass furnaces,especially high quality furnaces and specially glass furnaces

High Zirconia Bricks Specification

High Zirconia Bricks Using Precautions in Glass Kiln

1.Irregular Changes in Thermal Expansion

The expansion curve of the zirconia refractory bricks 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, and the temperature of the AZS refractory brick for the glass kiln 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 zirconia 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, high zirconia brick will cause a leakage of glass liquid. When used in the upper flame space of the kiln, the service life is very long, there is no problem of running glass. Therefore, the casting port is used outwards to extend the service life.

3.Eutectic

The AZS refractory brick and the fire 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.