6903200000 80
- Containing, by weight, more than 50 % of alumina (Al@2O@3) or of a mixture or compound of alumina and of silica (SiO@2)
6903201000 80
- - Containing, by weight, less than 45 % of alumina (Al@2O@3)
6903209000 80
- - Containing, by weight, 45 % or more of alumina (Al@2O@3)