The structure of the particle ceramic filter is a support plate with holes on the top and bottom, the particle filler is in the middle, and a layer of active adsorption material is plated on the particles, see the following figure. The thickness of the support plate is generally 12 mm, and the hole diameter is 4.5 to 13 mm.
The particulate ceramic filter uses MgO or Al2O3 as the filler, and the active adsorbent is selected according to the type of inclusions to be filtered. For high-temperature alloys treated with rare earth metals, rare earth metals are used as activators, and the problem of waterproofing should be solved when using calcium oxide particles.
CaO refractories are good filler materials for particulate ceramic filters. It can not only rely on the principle of physical adsorption, but also remove inclusions through chemical reactions. But there are two reasons that limit its large number of applications: First, it requires extremely high sintering temperature (above 1800 ℃) to obtain the necessary density and mechanical strength. The second is easy to hydrate under normal temperature and atmosphere.
The advantages of CaO refractories are high refractoriness, high alkalinity, good filtering properties of molten steel, and extremely rich resources. The way to improve the hydration resistance of CaO refractories for steel liquid filtration is to vigorously improve the sintering degree of CaO refractories, large crystal grain size, use ultra-high calcination or fused lime; form a protective film on the surface of CaO; fire in CaO The product is impregnated with tar or organic resin film as an intermediate transition measure; adding a small amount of chemical additives to CaO, its role is to reduce the sintering temperature of CaO, and at the later stage of sintering, a part of the liquid phase is generated inside the sintered body to promote the CaO grains. grow up.
