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Porous Ceramics

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

CL 2500

Primary Crystal Size = 1.7µm
Specific Surface Area = 0.90 m2/g
Na2O Content = 0.06%

Continuous Ground Calcined Aluminas

CL 2500 SG

Ground Median Size = 3.1µm
Ground Surface Area = 1.1 m²/g
Na2O Content = 0.06%

A 14 -325

Ground Median Size = 3.2µm
Ground Surface Area = 0.80 m²/g
Na2O Content = 0.03%

CL 3000 SG

Ground Median Size = 3.9µm
Ground Surface Area = 0.90 m²/g
Na2O Content = 0.06%

A 2 -325 CR

Ground Median Size = 5.0µm
Ground Surface Area = 0.70 m²/g
Na2O Content = 0.30%

A 35 -325 CR

Ground Median Size = 4.5µm
Ground Surface Area = 0.70 m²/g
Na2O Content = 0.11%

HVA FG

Ground Median Size = 4.8µm
Ground Surface Area = 0.70 m²/g
Na2O Content = 0.12%

WRA FG

Ground Median Size = 4.0µm
Ground Surface Area = 0.85 m²/g
Na2O Content = 0.12%

CT 800 FG

Ground Median Size = 3.5µm
Ground Surface Area = 0.90 m²/g
Na2O Content = 0.12%

CT 800 SG

Ground Median Size = 3.4µm
Ground Surface Area = 1.0 m²/g
Na2O Content = 0.12%

A 13 -325

Ground Median Size = 2.5µm
Ground Surface Area = 7.5 m²/g
Na2O Content = 0.20%

P 730

Ground Median Size = 2.2µm
Ground Surface Area = 9.0 m²/g
Na2O Content = 0.30%

Batch Ground Reactive Aluminas

CTC 40

Ground Median Size = 1.2µm
Ground Surface Area = 4.8 m²/g
Na2O Content = 0.08%

A 3000 FL C

Ground Median Size = 2.7µm
Ground Surface Area = 2.5 m²/g
Na2O Content = 0.07%

A 16 SG

Ground Median Size = 0.4µm
Ground Surface Area = 8.8 m²/g
Na2O Content = 0.07%

CT 3000 SG

Ground Median Size = 0.4µm
Ground Surface Area = 7.5 m²/g
Na2O Content = 0.08%

A 1000 SG

Ground Median Size = 0.6µm
Ground Surface Area = 8.2 m²/g
Na2O Content = 0.07%

A 1000 SGD

Ground Median Size = 0.6µm
Ground Surface Area = 8.2 m²/g
Na2O Content = 0.07%

CTC 20

Ground Median Size = 1.8µm
Ground Surface Area = 2.0 m²/g
Na2O Content = 0.12%

A 3000 FL

Ground Median Size = 2.7µm
Ground Surface Area = 2.5 m²/g
Na2O Content = 0.07%