Generalized Bogue computatiqns to forecast the mineralogical composition of sulfoaluminate cements based on fly ashes

Fly ashes, from an extensive database showing extremes in ratios of major o xides, are considered as potential raw meal ingredients for preparation of sulfoaluminate cements. Simple algorithmized, essentially Bogue-like, compu tations are performed in order to create a link between the chemical compos ition of raw meals and their mineralogical composition, as expected to resu lt from their burning The computations refer to a set of three-component ra w meals, all containing limestone and gypsum but differing in the kind of f ly ash introduced as the third raw meal component. The individual raw meal compositions are identified in computations, yielding three phase products, composed of C2S, C(4)A(3)(S) over bar and C(4)AF: The content of each phas e is within the following limits. C2S, 60.7-83.4 wt %; C(4)A(3)(S) over bar , 4.2-27.2 wt %; and C(4)AF 2.6-30.5 wt %. As a result, fly ashes are thus convenient raw soul-ces for, production of sulfoaluminate cements. Of speci al interest are fly ashes low in SiO2/A(2)O(3) or SiO2/(Al2O3 + Fe2O3) rati os, providing clinkers with the preferred proportions of the mineral phases .