Porous Ceramics
Porous ceramics are often used as filters for metal castings. These filters must effectively remove slag impurities, inclusions and remain inert to the metal in order to prevent oxidation. The filters must also have controlled thermal expansion and thermal shock resistance as they often encounter thermal cycling conditions.
Alumina is used in ceramic foam filters as an inert substrate material that can withstand the temperatures required for molten metal casting. Alumina-based foam filters are used for primary aluminum casting, foundry castings of steel, aluminum and other non-ferrous alloys, investment casting, and chemical processing.
Almatis aluminas for porous ceramic applications include soft and hard calcined aluminas available in continuous ground and batch ground versions. These aluminas have controlled crystal morphology, tight particle size distributions and specified impurity levels to ensure consistent performance and chemical inertness.
Unground Calcined Aluminas
Primary Crystal Size = 1.7µm
Specific Surface Area = 0.90 m2/g
Na2O Content = 0.06%
Safety Data Sheet
Product Data Sheet
Continuous Ground Calcined Aluminas
Ground Median Size = 3.2µm
Ground Surface Area = 0.80 m²/g
Na2O Content = 0.03%
Ground Median Size = 3.9µm
Ground Surface Area = 0.90 m²/g
Na2O Content = 0.06%
Ground Median Size = 5.0µm
Ground Surface Area = 0.70 m²/g
Na2O Content = 0.30%
Ground Median Size = 4.5µm
Ground Surface Area = 0.70 m²/g
Na2O Content = 0.11%
Ground Median Size = 4.8µm
Ground Surface Area = 0.70 m²/g
Na2O Content = 0.12%
Ground Median Size = 4.0µm
Ground Surface Area = 0.85 m²/g
Na2O Content = 0.12%
Ground Median Size = 3.5µm
Ground Surface Area = 0.90 m²/g
Na2O Content = 0.12%
Technical PaperGround Median Size = 3.4µm
Ground Surface Area = 1.0 m²/g
Na2O Content = 0.12%
Ground Median Size = 2.5µm
Ground Surface Area = 7.5 m²/g
Na2O Content = 0.20%
Batch Ground Reactive Aluminas
Ground Median Size = 1.2µm
Ground Surface Area = 4.8 m²/g
Na2O Content = 0.08%
Ground Median Size = 0.4µm
Ground Surface Area = 8.8 m²/g
Na2O Content = 0.07%
Ground Median Size = 0.4µm
Ground Surface Area = 7.5 m²/g
Na2O Content = 0.08%
Ground Median Size = 0.6µm
Ground Surface Area = 8.2 m²/g
Na2O Content = 0.07%
Ground Median Size = 1.8µm
Ground Surface Area = 2.0 m²/g
Na2O Content = 0.12%
Ground Median Size = 2.7µm
Ground Surface Area = 2.5 m²/g
Na2O Content = 0.07%
Ground Median Size = 3.1µm
Ground Surface Area = 1.1 m²/g
Na2O Content = 0.06%