The filter molten aluminum filtration is set in the molten aluminum filter box to remove inclusions. The filter is an aggregate mesh member made of refractory material, and a coating is formed on the surface of the mesh member.
The energy required for remelting aluminum is only 1/30 times the energy required for electrolytic refining of aluminum ore. Therefore, recycled aluminum scrap (remelting the aluminum scrap used as scrap) can save a lot of energy and bring great benefits.
However, aluminum shavings usually contain high concentrations of various impurities. Therefore, the molten aluminum or molten aluminum alloy obtained by remelting such aluminum scraps may contain various inclusions, including various non-metallic inclusions. Non-metallic inclusions are, for example, oxides originally contained in aluminum scraps that will be used as a raw material to be melted, or oxides generated due to the reaction of impurities contained therein. During the remelting process, the aluminum chips are filled with oxygen in the atmosphere. Compared with the use of aluminum ore, when aluminum scrap is used as a raw material, the above-mentioned problem of oxide inclusions is more serious. Examples of such oxide inclusions are alumina (Al 2 O 3), spinel (MgAl 2 O 4) and magnesium oxide (MgO).
Therefore, in the case of using aluminum scrap of such an aluminum alloy product as a part or all of the aluminum raw material, at least the inclusions must be removed from the molten Al obtained by melting the aluminum raw material. Therefore, in addition to a refining process such as degassing molten Al using a flux, a process of removing inclusions in molten Al by a filter is also performed.
Because the specific gravity of the inclusions is different from that of the molten aluminum, they remain static, so that the inclusions float in the molten aluminum or settle to the bottom of the molten aluminum. Therefore, it is possible to separate the inclusions from the molten aluminum. Ceramic foam filter is suitable for molten aluminum filtration, it is widely used in aluminum foundry.