The foam ceramic filter plate is injected into the plastic sponge with a mixed slurry of alumina and phosphate. After drying and sintering, the plastic sponge is volatilized, thereby forming tortuous channels and holes in the filter plate. The Porous Ceramic Filters are mostly square.
When filtering, the aluminum liquid flows along the curved channels and pores of the filter plate, and the impurities and inclusions in the aluminum melt come into contact with the pores on the surface of the filter plate under the action of deposition, inertia and interception, and stay inside the filter plate. Aluminum impurities and inclusions in the melt are separated from the liquid aluminum in the filter plate.
The service life of a single ceramic foam filter plate depends on the size of the filter plate, the number of holes and the metal cleanliness of the single filter plate. The size and pore size of a single filter plate is fixed. In order to improve the filtering effect, some manufacturers consider the use of two-stage filtering. Generally, the combination is used to achieve a good filtering effect. For impurities and inclusions with a particle size of about 20~30um, the removal rate can reach 75%~90%. The cleaning of the filter box and the replacement of the filter plate are simple, convenient, and fast, and it is very flexible in the production of various alloys.
The main purpose of the Porous Ceramic Filters is to remove impurities. Although the degassing device can also remove impurities, the removal effect is limited. For the production of high-precision products, degassing is far from meeting the requirements for the quality of castings. Under normal circumstances, after degassing, the aluminum plant will add filtering equipment to improve the purity of the aluminum liquid. Porous Ceramic Filters are the most versatile and economical filtration method. In order to extend the service life of DBF and PTF filter, some aluminum plants also use ceramic filter plates before filtering, so as to remove larger impurities in molten aluminum.