Refractory bricks, blocks, tiles and similar refractory ceramic constructional goods containing, by weight, > 7% but < 45% alumina, but > 50% by weight combined with silica
Opeka, bloki, ognjevarni, za vgraditev, nad 50% aluminijevega oksida (glinice), s 7% do 45% aluminijevega oksida (Al2O3)