Utilization of thermal power plant's fly ashes in the pigment production as an alternative raw material source

Abstract

At present time, considerable amount of fly ashes is disposed as a result of coal burning in thermal power plants. However, only minor parts of these ashes are evaluated and the rest is damped in stock areas. This is, of course, causing serious environmental problems. In the present study, it was tried to determine whether the fly ashes could be recycled in the way of colouring ceramic glazes and decorating ceramic objects, after being converted into pigment form. For such a purpose, fly ashes, (10-80 wt. %) Cr2O 3 and Al2O3 were used in the pigment production. Subsequent pigments were then employed in transparent wall and matte floor tile glazes, under-glaze decorations of white earthenwares. Finally, it was concluded that fly ash based pigments supplied ivory, brown and green colours in the related applications.