The ceramic filter board is referred to as CFF (ceramic foam filter). Ceramic Foam Filter CFF is a sponge-like product made of aluminum oxide, chromium oxide, etc. CFF has a unique three-dimensional network skeleton and interpenetrating pore structure. PPI is the number of holes per inch of length is used to express its specifications. The ceramic foam filter is relatively fragile and must be cleaned carefully after installation.
The aluminum melt smelted by electrolytic aluminum liquid has increased the gas content and slag content of the melt of remelted aluminum ingots. Therefore, the refining and filtering of the melt should be done well, and the slag content and slag content in the melt should be removed as much as possible. Gas content is the purpose of refining and the key to ensuring and improving product quality.
Although most of the slag inclusions are removed from the aluminum melt during refining, some fine slag particles, especially slag particles below a few microns, are difficult to remove by furnace refining and online refining, and they are still suspended in the aluminum melt. It is necessary to carry out strict filtration treatment before casting and rolling to allow the aluminum melt to pass through a certain filter medium, so that the impurity particles in the melt are intercepted by the surface of the filter medium, or captured by the inside of the filter medium, so as to achieve the purification of the aluminum melt.
The requirements of the ceramic foam filter plate are: the size specifications must be accurate; the flatness of the ceramic filter plate must be ensured; the porosity must be accurate to select according to the filtration accuracy and flow; there must be a certain air permeability. It must have a certain sintering strength as a parameter to measure whether the slag is dropped; the surface hardness of the filter plate must be high, and it must be coated with a special coating. The filter plate should be made of heat-resistant aluminum alloy. Since the high-temperature aluminum liquid suddenly contacts the filter during discharge and makes the filter close to the temperature of the aluminum liquid, the filter should have a smaller linear expansion coefficient. Because it is immersed in molten aluminum, the filter is not allowed to be washed out and softened. The chemical stability of the filter should be high, and it will not react with aluminum at high temperatures.