METHOD OF BINDING AGENT PREPARING Russian patent published in 1997 - IPC

FIELD: building industry. SUBSTANCE: invention relates to method of preparing the binding agent of low water requirement that has clay shale roasted at 550-950 C. Clay shale has the following composition, wt.-%: SiO₂, 50-54; Al₂O₃, 18-22; Fe₂O₃, 9-10; CaO, 0.5-0.9; MgO, 2-4; R₂O, 1.5-2.5; TiO₂, 0.5-1.2; and nonidentified components, the balance. Method of preparing binding agent involves grinding the mixture of portland cement clinker, gypsum and superplasticizer agent up to specific surface 3000-3500 cm²/g. Then intermediate binding agent is ground additionally with the indicated roasted clay shale to obtain the final specific surface value of clinker component 4000-5500 cm²/g and that of specific surface of the roasted clay shale - 6000-9000 cm²/g. EFFECT: improved method of preparing. 3 tbl