Refractory assembly for containment of molten Al-Li alloys

Claim 1

A refractory assembly suitable for containment of molten aluminum-lithium alloys, comprising (a) a refractory brick comprising (i) about 80 to 95 wt % silicon carbide, and (ii) about 3 to 20 wt % of a nitride bonding agent dispersed throughout said silicon carbide, said bonding agent being selected from the group consisting of silicon nitride, silicon oxynitride and mixtures thereof, and (b) a seam joined to said brick, said seam comprising a mortar mix applied to said brick and then fired at an elevated temperature, said mortar mix comprising (i) about 50 to 85 wt % of a particulate nitride refractory filler selected from the group consisting of silicon nitride, silicon oxynitride, silicon aluminum oxynitride wherein the aluminum and oxygen are in a solid solution of silicon nitride, and mixtures thereof, (ii) about 15 to 50 wt % of a colloidal sol binder comprising an aqueous suspension of binder solids selected from the group consisting of silica, silicon nitride, silicon oxynitride and silicon aluminum oxynitride wherein the aluminum and oxygen are in a solid solution of silicon nitride, the quantity of binder and the concentration of binder solids in said suspension being sufficient to coat substantially all of the particulate filler and to form a plastic mixture therewith, and (iii) less than about 2 wt % of the oxides or hydroxides of magnesium, calcium, chromium and manganese.

Claim 12

A method for making a refractory assembly comprising the steps of (a) preparing a mortar mix comprising (i) about 50 to 85 wt % of a particulate nitride refractory filler selected from the group consisting of silicon nitride, silicon oxynitride, silicon aluminum oxynitride wherein the aluminum and oxygen are in a solid solution of silicon nitride, and mixtures thereof, (ii) about 15 to 50 wt % of a colloidal sol binder comprising an aqueous suspension of binder solids selected from the group consisting of silica, silicon oxynitride, silicon nitride and silicon aluminum oxynitride wherein the aluminum and oxygen are in a solid solution of silicon nitride, the quantity of binder and the concentration of binder solids in said suspension being sufficient to coat substantially all of the particulate filler and to form a plastic mixture therewith, and (iii) less than about 2 wt % of the oxides or hydroxides of magnesium, calcium, chromium and manganese: (b) applying the mortar mix to form a seam between a pair of opposed refractory bricks each comprising (i) about 80 to 95 wt % silicon carbide, and (ii) about 3 to 20 wt % of a nitride bonding agent dispersed throughout said silicon carbide, said bonding agent being selected from the group consisting of silicon nitride, silicon oxynitride and mixtures thereof, said seam and bricks comprising, in combination, a refractory assembly.

Claim 13

A method for making a refractory assembly comprising the steps of (a) preparing a mortar mix comprising (i) about 50 to 85 wt % of a particulate nitride refractory filler selected from the group consisting of silicon nitride, silicon oxynitride, silicon aluminum oxynitride wherein the aluminum and oxygen are in a solid solution of silicon nitride, and mixtures thereof, (ii) about 15 to 50 wt % of a colloidal sol binder comprising an aqueous suspension of binder solids selected from the group consisting of silica, silicon oxynitride, silicon nitride and silicon aluminum oxynitride wherein the aluminum and oxygen are in a solid solution of silicon nitride, the quantity of binder and the concentration of binder solids in said suspension being sufficient to coat substantially all of the particulate filler and to form a plastic mixture therewith, and (iii) less than about 2 wt % of the oxides or hydroxides of magnesium, calcium, chromium and manganese: (b) applying the mortar mix to form a seam between a pair of opposed refractory bricks each comprising (i) about 80 to 95 wt % silicon carbide, and (ii) about 3 to 20 wt % of a nitride bonding agent dispersed throughout said silicon carbide, said bonding agent being selected from the group consisting of silicon nitride, silicon oxynitride and mixtures thereof, said seam and bricks comprising, in combination, a refractory assembly.