Molten Al Filtering by advanced ceramic foam filter

AdTech provides an advanced alumina ceramic foam filter for molten Al filtering, it has an improved efficiency of removing especially fine inclusions of about 10 to 25 μm. Ceramic foam filters are widely used for molten aluminum filtration in primary and secondary aluminum foundries, they are also applied as filtering media in gas-liquid and liquid-solid separation engineering.

Molten Al Filtering

Recycling aluminum scrap (i.e. remelting the aluminum scrap for use as raw material to be melted) can give a considerably large amount of energy savings and thus bring great advantages.

However, aluminum scrap generally contains various impurities at high concentrations. Thereby, the molten aluminum or molten aluminum alloy obtained by remelting such an aluminum scrap is likely to contain a variety of inclusions including many kinds of non-metallic inclusions. The non-metallic inclusions are, for example, oxides contained originally in the aluminum scrap to be used as the raw material to be melted or oxides produced by the reaction of the impurities contained in the aluminum scrap with oxygen in the atmosphere during the remelting.

Consequently, in case of using such an aluminum scrap of aluminum alloy products as a part or all of the raw aluminum material, it is necessary to remove inclusions at least from the molten Al obtained by melting the raw aluminum material. Therefore, in addition to the refining process such as a degassing of the molten Al with using fluxes, performed has been a process of removing inclusions from the molten Al such as the killing method, active gas method and molten Al filtering.

AdTech provides an advanced ceramic foam filter with an improved filtering ability of removing particularly fine inclusion particles from molten aluminum or molten aluminum alloy. The advanced filter includes an aggregate meshed member made of a refractory material and a coating layer formed on a surface of the aggregate meshed member.

A ceramic foam filter for molten aluminum alloys chemical composition comprising: 20 – 70 wt% Al2O3, 20 – 60 wt% SiO2, 0-10 wt% CaO, 0-10 wt%; MgO and 2-20 wt% B2O3. Ceramic foam filter is a phosphate-free, high alumina-based product, It is characterized by high porosity and mechanochemical stability and excellent resistance to thermal attack and corrosion from molten aluminum, It can effectively remove inclusions, reduce trapped gas and provide laminar flow when filtrating molten aluminum, it is machined to tight dimensional tolerance during production, this combination of physical properties and precise tolerance make them first choice for molten non-ferrous filtration.