Description of Corundum Castable
Corundum concrete mix is an unmolded refractory material formed by mixing corundum and superbauxite clinker as aggregate and powder, and some amount of pure calcium aluminate cement, binders and additives. The alumina content of corundum casting is more than 90%, which provides a large amount of corundum as the main crystalline phase. Its advantages are high strength, volume stability and corrosion resistance. Corundum casting materials are usually made by pouring method, which can be cast in one-piece liners or spliced in situ.
Characteristics of Corundum Castable
| Name of indicator | Norma |
|---|---|
| Fire resistance, ℃, max. | 1800 |
| Mass fraction, %: | |
| Al2O3, not less | 90 |
| Fe2O3, not less | 1 |
| CaO , %, not less than | 0,4-0,5 |
| SiO2, % | electively |
| Compressive strength, MPa, after heat treatment at: | |
| - 110oC, not less | 60 |
| - 1350oC, not less | 30 |
| Mass fraction of moisture, %, within limits | 0,5-1 |
| Linear shrinkage, %, at temperature 1350 oC, not more, | 1 |
| Grain composition, %: | |
| - residue on grid No. 5, not more than | 10 |
| - residue on grid No. 2, not more than | 45 |
| - residue on mesh No. 0.5, not more than | 70 |
| - residue on grid No. 009, not more than | 80 |
Classification of Corundum Castable
Zirconia corundum castable
Zirconium corundum concrete mixes are basically refractory castings with ZrO2 and Al2O3 as the main components. The addition of ZrO2 improves the performance of the castings by providing excellent thermal shock resistance and stability. It has excellent corrosion resistance and high temperature resistance.
Chrome-corundum concrete mixes
Chrome corundum concrete mixes are mainly made of high-strength refractory materials such as corundum and Cr2O3 in the form of aggregates and fine powders. It belongs to the series of composite corundum casting materials and is a neutral refractory material. The addition of chromium oxide improves the characteristics of the casting material, making it particularly suitable for applications requiring high wear and corrosion resistance.
Method of construction of concrete corundum mix
Surface treatment
Ensure that the construction surface is clean, dry, smooth and free of other contaminants
Mixing molding materials
Mix several bags of molding materials according to the required materials and add a certain amount of water to adjust the moisture content according to the construction moisture requirements
Stirring
Add the potting and glue mixture to the mixer, add water and mix until the color is uniform and lumps can be picked up with your hands without leaking (completed within 30 minutes).
Vibration
The casting material should also be poured using a plug-in vibrator or flat vibrator, and the height of the casting layer should not exceed 400 mm. Castings applied by vibration can help eliminate porosity and improve the compactness and strength of the cladding.
Curing
The finished structure body should be cured naturally in a dry environment for 5-7 days at a temperature of 5-35℃. Avoid vibration of the structure body during maintenance.
Application of Corundum Castable
Metallurgy
SBC is used for refractory walls and intermediate layers in high-temperature furnaces and chambers, such as steel or aluminum melting chambers. It has high heat resistance and the ability to withstand aggressive chemical media.
Chemical industry
SBC is used for chemical resistant surfaces and structures used in aggressive environments such as reactors, separators, pipelines and tanks.
Furnaces and combustion chambers
SBC is used to create refractory walls and flooring in furnaces, boilers and combustion chambers where high heat and abrasion resistance is required.
Abrasive tools
SBC can be used for abrasive tools such as grinding wheels and stones due to its high abrasion resistance.
