China Suppliers Factory Fused Cast β-Alumina Block RTK-H for Superior Corrosion Resistance and Low Contamination
Fused and cast alumina products are alumina series fused and cast blocks made of high-purity alumina raw materials, which are melted in an electric arc furnace at a high temperature above 2000℃. Due to the use of high-purity raw materials, less impurities and almost no matrix glass phase, it has excellent low contamination performance to the molten glass.
The crystal phase structure of the fused alumina series is composed of α-alumina and β-alumina, which has different composition ratios. The products of different varieties have different properties and can meet different operating conditions. According to its crystal phase structure, it is divided into α-β corundum brick (RTK-M), β-corundum brick (RTK-H) and α-corundum brick (RTK-A). Further classification shall be made according to the appearance quality specification level and casting method. These classifications can meet the different application requirements of fused cast corundum series in glass furnaces and metallurgical electrolyzers.
RTK-H Key Features:
RTK-H is composed of nearly 100% β-alumina with a dense structure and high resistance to spalling. It especially shows extremely high corrosion resistance to strong alkali vapor, contains almost no glass phase, and causes no contamination to molten glass. It can be used for superstructures with little glass raw material scattering or oxy-fuel combustion furnaces, where it can give full play to its excellent performance.
| Chemical Composition | Typical Value |
|---|---|
| Al₂O₃ % | 92.5 |
| Na₂O % | 6.5 |
| SiO₂ ＋ CaO ＋ Fe₂O₃ ＋ TiO₂ % | ≤1 |
| Physical Property | Typical Value |
|---|---|
| Bulk density (dense part) g/cm³ | 2.9 |
| Normal temperature compression resistance MPa | 80 |
| Load softening start temperature (0.2 MPa) | 1700 |
| Calculate Specific Gravity | Typical Value |
| PT g/cm³ | 2.6 |
| WS g/cm³ | 2.8 |
What are fused and cast alumina products?
Fused and cast alumina products are high-purity refractory blocks melted in an electric arc furnace at temperatures exceeding 2000℃. They feature minimal impurities and almost no matrix glass phase, providing excellent low-contamination performance for molten glass.
What is the composition and main feature of RTK-H?
RTK-H is composed of nearly 100% β-alumina. It has a dense structure, high resistance to thermal spalling, and outstanding corrosion resistance to strong alkali vapors, ensuring no contamination to the molten glass.
Where is RTK-H typically applied in glass furnaces?
RTK-H is ideal for superstructures with minimal glass raw material scattering and is highly recommended for oxy-fuel combustion furnaces to resist strong alkali vapor corrosion.
How are fused cast alumina series classified?
They are classified based on their crystal phase structure into α-β corundum brick (RTK-M), β-corundum brick (RTK-H), and α-corundum brick (RTK-A), as well as by casting methods and appearance specifications.
Why do these alumina products offer low contamination to molten glass?
Because they are manufactured using high-purity alumina raw materials, resulting in extremely low impurity levels and the virtual absence of a matrix glass phase, which prevents glass defects.