C | CHEMISTRY; METALLURGY |
04 | CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES |
B | LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE |
2235 | Aspects relating to ceramic starting mixtures or sintered ceramic products |
02 | Composition of constituents of the starting material or of secondary phases of the final product |
30 | Constituents and secondary phases not being of a fibrous nature |
32 | Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides |
3231 | Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof |
3251 | Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof |