C CHEMISTRY; METALLURGY
C04 CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
C04B LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
C04B7/00 Hydraulic cements
C04B7/36 Manufacture of hydraulic cements in general
C04B7/38 Preparing or treating the raw materials individually or as batches; , e.g. mixing with fuel;
C04B7/42 Active ingredients added before, or during, the burning process
C04B7/421 Inorganic materials