Explanatory notes
… Cr 2 O 3 6902.20 - Containing by weight more than 50 % of alumina (Al 2 O 3 ), of silica (SiO 2 ) or of a mixture or … chemical, ceramic, glass and other industries. It includes, inter alia : (1) Bricks of all shapes … wedge shaped, cylindrical, semi-cylindrical, etc.), including keystones and other specially shaped bricks (e.g., …