The technology of ceramic foam filtration outside the furnace has long been an important means of purifying molten aluminum. Reflected in the alloying, purification and refinement processing technology of the smelting process. The smelting of aluminum alloy is the first step in the aluminum alloy processing process, and it is also a crucial link.
The ceramic foam filter plate has a unique three-dimensional network framework and porous ceramic products with an interpenetrating pore structure.
The foam ceramic filter plate filters and removes impurities, which can significantly improve the quality of ingots and reduce the rejection rate. Since then, the corresponding research and development of foamed ceramic filter materials have been promoted in the metallurgical industry.
The production of ceramic foam filter (CFF) generally uses a three-dimensional network structure, and organic foam with connected pores as a carrier, immersed it in a special ceramic slurry with thixotropy, and adopts a special roll extrusion process to make The ceramic slurry is evenly spread on the skeleton of the carrier, but it is dried and solidified and then fired at a high temperature.
The ceramic foam filter molten aluminum filtration mechanism is generally described as diffusion interception and inertial collision interception or screening, sedimentation and deep bed filtration.
When the molten metal passes through the ceramic foam filter with complex structure, the filter medium filters out the inclusions larger than the pore size of the filter surface through mechanical separation, and makes them precipitate at the inflow end of the filter liquid metal.
As the accumulation of inclusions on the surface of the filter increases, a layer of “filter cake” will gradually form, which will further narrow the flow channel of the molten metal. Therefore, the surface of the filter medium can filter out finer inclusions. At the same time, the media also has a filtering function, and any area is a possible location for intercepting inclusions.