The effect of BaCO3 addition on the sintering behavior of lignite coal fly ash

Abstract

The effect of BaCO 3 (witherite) addition on the sintering behavior of lignite coal fly ash taken from the Seyitömer power plant of Kütahya/Turkey was examined at temperatures of 1100, 1150 and 1200 C in air atmosphere. Bloating of the fly ash samples sintered at 1150 C was prevented, that is, the decomposition temperature of CaSO in the fly ash is shifted to a higher temperature, and their physicomechanical properties (porosity, water absorption, bulk density and bending strength) were improved with BaCO 3 4 addition. Positive effects of BaCO , however, were not seen on the fly ash samples sintered at 1100 C. All the fly ash samples sintered at 1200 C were bloated due to the gas evolving and also they melted. During the thermal treatment at 1150 C a phase transformation from CaSO (Barite) occurred in the fly ash with BaCO 3 3 4 addition as seen from the X-ray diffraction (XRD) patterns and the bar shaped fly ash samples with BaCO 3 (anhydrite) to BaSO saved their structural integrity up to 1150 C.

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