AZS fused brick

AZS fused brick, also known as fused zirconium corundum brick, is a high-performance refractory material.

1. Naming and composition

Naming: AZS is the abbreviation of the three chemical components (alumina, zirconium oxide, silicon dioxide) of the Al2O3-ZrO2-SiO2 ternary phase diagram arranged in order of their content, where Al2O3 is A, ZrO2 is Z, and SiO2 is S. For example, the abbreviation of No. 33 fused zirconium corundum brick is AZS-33#, No. 36 and No. 41 are AZS-36# and AZS-41# respectively.

Composition: AZS fused brick is mainly composed of pure alumina powder, zirconium oxide (ZrO2 about 65%) and silicon dioxide (SiO2 about 34%) and other raw materials. It is melted at high temperature in an electric furnace and then injected into the mold for cooling.

2. Manufacturing process

1). Mix selected zircon sand and industrial alumina powder in a certain ratio (usually 1:1), and add a small amount of Na2O (added in the form of sodium carbonate) and B2O3 (added in the form of boric acid or borax) as flux.

2). After mixing evenly, melt at high temperature (such as 1800~2200℃) and cast into shape.

3). After cooling, cut and process to make AZS fused bricks with specific shapes and sizes.

3. Structure and performance

Structure: The petrographic structure of AZS fused bricks consists of the eutectoid of corundum and zirconite and the glass phase. From a phasic point of view, it is the eutectoid of corundum phase and zirconite phase, and the glass phase is filled between their crystals.

Performance:

1). High temperature resistance: It can withstand long-term use in high temperature environment without deformation or damage.

2). High strength and high compressive resistance: It has excellent mechanical properties and compressive resistance.

3). Excellent thermal shock resistance: able to withstand rapid temperature changes without cracking or breaking.

4). High bulk density and thermal conductivity: has high bulk density and good thermal conductivity.

5). Good wear resistance and acid resistance: can maintain a long service life in harsh environments.

6). Alkali corrosion resistance: has strong resistance to alkaline substances.

4. Application fields

AZS fused bricks are widely used in various high-temperature industrial fields due to their excellent performance, such as:

1). Glass industry: mainly used as refractory materials for glass pool kilns, glass electric kilns and other equipment, especially for the most severely eroded and corroded parts such as melting pools.

2). Steel industry: used for slideways in steel production and other parts that require high temperature resistance and erosion resistance.

3). Soda ash industry: refractory materials for soda ash kilns.

5. Casting method

The casting method of AZS fused bricks varies according to their application requirements and process characteristics, mainly including:

1). Ordinary casting method: suitable for the manufacture of AZS fused bricks with general requirements, but may produce larger shrinkage cavities.

2). Inclined casting method: suitable for the manufacture of long bricks, which can condense shrinkage cavities at one end of the product and improve the density of the product.

3). Quasi-shrinkage-free casting: similar to shrinkage-free casting, but a small amount of shrinkage cavities may remain on the upper part of the brick body.

4). Shrinkage-free casting method: can completely eliminate shrinkage cavities, making the product composition uniform and the structure dense.

In summary, AZS fused bricks are a high-performance refractory material with excellent performance and a wide range of applications. Through different casting methods and process parameter adjustments, the needs of different industrial fields for refractory materials can be met.