Home – Home – Jornals – Chemistry for Sustainable Development 2010 number 3

High-calcium volatile ash of brown coal from the Berezovsky open-pit mine of the Kansk-Achinsk basin selectively sampled from different points in the ash-collecting installation at BSRES-1 (convective pit, prechamber, and each of the four fields of electrofilters) was studied. Differences between these middlings in chemical composition, dispersity, binding properties were established. The types of volatile ash samples were determined in the system of their chemical classification. It was shown that the ash samples of Beresovsky, Nazarovo coal from the 1^st - 4^th fields of electrofilters differ from all the known kinds of ash by the maximally high calcium content. It follows form the phase diagram of the system СаО-Al₂O₃-SiO₂ that hydraulically active phases similar to the basic phases of the Portland cement clinker may be formed from the ash of electrofilters. Due to differences in the composition of ash samples, the ratio of these phases will be changed, too. Along with differences in particle size, this allows one to obtain Portland cement with special properties on this basis. Six fractions of magnetic microspheres of high purity were obtained; their chemical, quantitative phase composition and morphology were studied, including the contribution from globules of different kinds and the structural texture features of the material; methods of application were determined; the trends of changes in composition and morphology with changes in fraction size were established.