Abstract:
Effect of ashing temperature on sintering behavior of ashes from combustion of coal and straw blends was investigated. Blends of a Chinese anthracite, Jincheng coal, and wheat straw were burned at three different temperatures. The resulting ash samples were then subjected to the sintering temperature measurement using a pressure-drop sintering device, morphological and mineralogical characterization with scanning electron microscope (SEM) fitted with X-ray energy dispersive spectroscopy (EDS) and X-ray diffractometry analyzer (XRD), respectively. For the same coal and biomass blends but different ashing temperatures, their sintering temperatures decrease in different extent. In addition, sintering temperatures of the blends under lower ashing temperature are lower than that under the higher ashing temperature. SEM imaging show that the texture of ash samples from lower ashing temperature is irregular, loose and more fibrous. The ashes under higher ashing temperature are mostly in spherical-shape, indicating ash melting has occurred during combustion. The XRD analysis reveals that blends of ash from Jincheng coal and straw under low ashing temperature has low sintering temperature due to more fluxing minerals, like K-containing mineral. The high sintering temperature of the ash blends depends on the Ca-containing minerals like anorthite with high melting temperature.