The influences of mineral behaviour on blended coal ash fusion characteristics

The ash fusion characteristics and mineral behaviour of three kinds of indi vidual coal ash and a series of two-component blended ashes were studied. T he ash fusibility and chemical composition were measured and analysed. The samples were heated progressively from 800 degrees C to the initial deforma tion temperature (IT) at 100 degrees C intervals in reducing atmosphere. Mi neral composition and type at each temperature interval were determined by X-ray diffraction (XRD) analysis. The results show that blended ash softeni ng temperatures do not change linearly with blending ratios. It can lie bet ween or lower or higher than that of the individual parent coals. Some comb inations of component coal's mineral produce low-melting eutectic minerals at high temperature and this is the main reason causing the non-arithmetic averaging of softening temperature of blended ash. It is consistent with th e results from the ternary system phase diagram. (C) 1999 Elsevier Science Ltd. All rights reserved.