Reduction in Aluminum Alloy Attack on Aluminosilicate Refractories by Addition of Rare‐Earth Oxides

Abstract

Several aluminosilicate compositions were tested for molten 7075 aluminum alloy attack with and without the addition of 10% Na 2 CO 3 . The extent of corrosion was proportional to the silica content of the refractory and especially of the matrix phase. The addition of rare earths up to 15% by weight to the aluminosilicates virtually eiiminated corrosion. Bastnasite, a rare‐earth concentrate, was found to be a more effective additive at low concentrations than either CeO 2 or La 2 O 3 alone in rendering the aluminosilicates corrosion resistant.