| 摘要 |
PURPOSE:To obtain a filter material for metallic molten metal having high collecting capacity for impurities and long service life by binding ceramic aggregate particles with an inorganic binder of a frit having a specified compsn. constituted of B2O3, Al2O3, CaO and MgO and having specified particle size. CONSTITUTION:Ceramic aggregate particles are binded with an inorganic binder to obtain a porous filter material. At this time, as the above binder, a frit constituted of, by weight, 15 to 80% B2O3, 2 to 60% Al2O3, 0 to 30% CaO and 5 to 50% MgO and having <=35mum 50% average particle size is used. Furthermore, as the above aggregate, ceramic particles of alumina or the like having about 0.3 to 3.0mm average particle size and about 100 to 130 shape index are suitably used. This aggregate, 100 pts.wt., is blended with the above binder by about 4 to 20 pts.wt., which is heated to about 1200 to 1400 deg.C to melt the binder, and after that, gradual cooling is executed to form a porous filter material. In this way, the filter material for metallic molten metal having high bending strength and high collecting capacity for impurities by formed aluminum boride crystals can be obtd. |
