Silicon nitride (Si3N4) rollers or balls

Ceramic proppants, containing aluminium oxide, silicon oxide and iron oxide

Supports for catalysts, consisting of porous cordierite or mullite ceramic pieces, of an overall volume of not more than 65 l, having, per cm² of the cross-section, not less than one continuous channel which may be open at both ends or stopped at one end

extruded fired ceramic bound multicellular cylindrical structure, -5 % or more by weight but not more than 70 % by weight of activated carbon, -30 % or more by weight but no more than 90 % by weight of ceramic binder, -with a diameter of 29 mm or more but no more than 41 mm, -a length of not more than 150 mm, -fired at temperature of 800 °C or more

2 % or more of diboron trioxide, - 28 % or less of silicon dioxide and - 60 % or more of dialuminium trioxide

Supports for catalysts, consisting of porous ceramic pieces, of a blend of silicon carbide and silicon, with a hardness of less than 9 on the Mohs scale, with a total volume of not more than 65 litres, having, per cm² of the surface of the cross section one or more closed channels at the tail end

Supports for catalysts or filters, consisting of porous ceramics made primarily from oxides of aluminium and titanium; with a total volume of not more than 65 litres and at least one duct (open on one or both ends) per cm² of cross section

Other