RAW MIX FOR PREPARING SULFOFERRITE CEMENT CLINKER Russian patent published in 2000 - IPC

FIELD: building materials, industry, more particularly preparation of shrinkage-free cements. SUBSTANCE: in order to prepare such cements, sulfoferrite clinker is added to ordinary portland clinker in amount of 4-10 wt. %. Raw mix comprises carbonate component, ferrous component and gypsum-containing component, fuel ash resulting from combustion coal or brown coal, said ash containing at least 19 wt of aluminium oxide, ratios of components being as follows, wt.%: ferrous component, 25- 40; gypsum-containing component, 11-12; said ash, 1-5; and carbonate component, the balance. Raw mix may comprise, as gypsum containing component, natural or chemical gypsum which is production waste. EFFECT: improved properties of the raw mix. 2 cl, 2 tbl