Foam ceramic filtration is the last step in the purification of aluminum melt, and it is particularly important to choose the second generation of foam ceramic filter plates. Correct selection of filter plates can improve the cleanliness of the aluminum melt.
The selection of foam ceramic filter plates should first be determined according to the impurity content in the aluminum melt, the melt transfer flow rate and the quality requirements of cast aluminum products.
The aluminum melt contains a lot of impurities, and the quality requirements of the cast products are general, and a foam ceramic filter plate with a larger hole mesh can be used, and a glass fiber cloth is added in front of the filter plate for coarse filtration. In this case, it is important to use glass wool cloth for coarse filtration when casting aluminum melt semi-continuously. It can intercept the slag flowing out when the furnace is opened and the slag washed off on the launder to prevent the filter plate from being blocked.
When the quality requirements of casting products are high, a new generation of foam ceramic filter plates with small holes and large meshes are used. For example, an aluminum company produces aluminum foil blanks, aluminum company 1 produces high-quality hot-rolled slabs, aluminum company 2 produces high-quality military aluminum products, and aluminum company 3 produces high-quality industrial aluminum profiles. The foam ceramic filter plate produced by our company. If the ceramic plates of 30ppi and 60ppi are 305mm×305mm×50mm, 381mm×381mm×50mm, 432mm×432mm×50mm, 508mm×508mm×50mm for filtering, the aluminum melt can be more ideally clean. Spend.
The selection of filter plate specifications is determined according to the flow rate of aluminum melt per unit time and the total throughput of aluminum melt. If the flow rate is large and the total throughput is large, and the aperture of the filter plate is small, the larger size filter plate is selected.
When choosing a filter plate, you should also watch its color, shoot its body, and burn its objects.
The color of the filter plate is pure and free of impurities, indicating that the material is uniform. It is sticky but not sticky, which means that the surface is not sprayed with adhesive, which will not cause secondary pollution of aluminum liquid.
Holding the filter plate with one hand and slapping the filter plate with the other hand in a clapping style to continuously drop the ceramsite, it is an inferior filter plate, which will cause secondary pollution of molten aluminum.
Use an open flame or electric heating to heat the filter plate to red, and immediately cool it at room temperature without cracking and slag, it is a good filter plate.
The effective specific surface area or porosity of the foam should be carefully evaluated when purchasing filter plates. The mesh uniformity of the surface layer of the filter plate can be observed, and then it is cut open to observe the mesh uniformity of the section. If possible, the porosity can be calculated by the drainage method. If the three-dimensional mesh is uniform and the porosity is relatively large, it is an excellent foam ceramic filter plate.
It should be specially pointed out that the secondary pollution of the melt that may occur during the solidification and forming process after the aluminum melt leaves the filter box should be prevented. In this process, the sintered flow tank, front box, distribution plate and hot cap made of fused silica ceramics with long life, high strength, non-stick aluminum and good thermal insulation are used, and dehumidified and cleaned in time to eliminate possible pollution sources. , to ensure the cleanliness of the aluminum melt can not be ignored.