The casting ceramic filters are composed of many uniform and numerous micropores. When the aluminum liquid passes through these micropores, the suspended matter is trapped on the surface of the filter medium, and the fluid passes through the micropore channels to produce various physical effects, so as to achieve the effects of mechanical filtration, purification, diffusion, and fluidization.
The metal filter screen and fiber cloth filter can only remove the larger inclusions in the aluminum alloy melt, but cannot remove the inclusions below the micron level. The metal filter screen will also pollute the aluminum alloy. The ceramic foam filter plate can filter out fine inclusions and significantly improve the mechanical properties and appearance quality of the castings.
Studies have shown that while removing slag, casting ceramic filters can also reduce the hydrogen content in the aluminum melt. Because of its good slag removal effect, simple operation, easy matching with other parts, and low cost, it has become a conventional purification method in the aluminum processing industry.
Aluminum production is composed of bauxite mining, alumina production, aluminum electrolysis, smelting and casting and other production links.
The bauxite ore is first mined, and aluminum ore powder is produced through processes such as water washing and grinding, and then alumina is obtained through four complex processes such as roasting.
Alumina manufacturers have adopted different production processes in their production, mainly including Bayer process, soda lime sintering process and Bayer-sintering combined process. Generally, high-grade bauxite is produced by the Bayer method, and medium and low-grade bauxite is produced by the combined method or the sintering method. Due to its simple process and low energy consumption, the Bayer process has become the most important method used in the current alumina production, and its output accounts for about 95% of the total global alumina production.
Alumina electrolyzes aluminum metal under the action of a strong current, and this process is called electrolytic aluminum.
In terms of metallurgy, the use of ceramic foam filter plates to remove foreign impurities in the aluminum melt, such as slag and inclusions, is one of the most effective melt purification methods.