Abstract: Herein disclosed is a filter medium for molten metals which consists of a sintered body of a mixture comprising 100 parts by weight of at least one refractory grain selected from the group consisting of alumina particles and Al.sub.2 O.sub.3.MgO spinel crystal particles; and 5 to 25 parts by weight of an inorganic binder which comprises 60 to 90% by weight of Al.sub.2 O.sub.3.MgO spinel crystal powder, 5 to 12% by weight of B.sub.2 O.sub.3, and not more than 30% by weight of at least one oxide selected from the group consisting of Al.sub.2 O.sub.3, MgO and TiO.sub.2. The filter medium is used for filtering off solid impurities mixed in molten metals, in particular, molten aluminums.

Abstract: A ceramic filter used for filtering molten metal, particularly molten aluminum, made by sintering the composition comprising 90 parts by weight of electrofused alumina for an aggregate and 5 to 15 parts by weight of an inorganic binder. The inorganic binder comprises 5 to 15 wt % of B.sub.2 O.sub.3, 15 to 50 wt % of MgO, 3 to 10 wt % of SiO.sub.2 and the remainder Al.sub.2 O.sub.3.