| 摘要 |
<p>PURPOSE:To obtain a high strength filter medium for molten metal excellent in filterability by mixing specific percentages of binding material having a specific composition consisting of Al2O3, B2O3, CaO, and MgO and also having respectively specified pore, amount of permeation, and strength with ceramic filler grains. CONSTITUTION:A porous filter medium is formed by adding and mixing 4-20 pts.wt. inorganic binding material into 100 pts.wt. ceramic filler grains. In the above filter medium, the above inorganic binding material has a composition consisting of, by weight, 2-60% Al2O3, 15-80% B2O3, 0-30% CaO, and 5-50% MgO. Further, average pore diameter, the amount of permeation (differential pressure 14mmAq) per unit area (cm<2>), and bending strength at room temp. are regulated to 100-300mum, >=0.45l/min, and 50kg/cm<2>, respectively. Moreover, it is preferable to regulate the shape index of the above ceramic filler grains to 100-130, and proper average grain size is about 0.3-3.0mm. By this method, the filter medium for molten metal excellent in molten metal permeability and inclusion collecting property, having high strength, and practically free from breakage can be obtained.</p> |
