CEMENT PRODUCTION PROCESS Russian patent published in 2000 - IPC

FIELD: manufacture of building materials. SUBSTANCE: raw mix containing, in specified proportions, carbonate component, heat and power station ash-slag waste, air-slaked lime, sludgy chemical production wastes, and correcting additive containing metallurgical slag and/or quartz sand is fired to form cement clinker, which is then ground together with gypsum. Process is distinguished by that above sludgy wastes are sludge suspension prepared from chemical production effluents neutralized with lime, which together with air-slaked lime is preliminarily treated with carbon dioxide-containing gas at sludge suspension-to-gas weight ratio 1:(0.6-5.6) and temperature 80 to 150 C for 0,01 to 7 s and then dehydrated until moisture content 40-60% is attained. EFFECT: improved characteristic s of cement resulting in higher strength of cement products. 5 cl, 2 tbl