Synergistic behaviors of anthracite and dried sawdust sludge during their co-combustion: Conversion ratio, micromorphology variation and constituents evolutions

This paper studied the synergistic behaviors of anthracite and dried sawmill sludge (DSS) in the conversion ratio (CR) of combustible substances, micromorphology variation and constituents' evolutions. The results showed that the blend CRs were the highest, and CRs increased with O2 and temperature. In ash formation, DSS mainly contributed to the fly ash yield, while anthracite determined the morphology of bottom ash. The carbon proportion of combusted blend decreased to 0, revealing its thorough combustion, thereby proving the synergistic effects between anthracite and DSS. The disappearances of CC, CH2 and OH determined by FT-IR indicated the burning losses of kinds of hydrocarbons, meanwhile the identified enlarged bands of SiO, AlO and FeO suggested the formations of inorganic compounds. The XRD results further demonstrated the formations of SiO2, Al2O3, CaSO4 and Fe2O3, the rising temperature promoted their melting/conglomeration process, thereby lowering the XRD peaks since the mischcrystals generations. The oxygen-enrich atmosphere inhibited the formations of SiO2 and Al2O3 but promoted the generation of Fe2O3, and accelerated the formation of porous-smooth ash. The addition of CaCO3 assisted the pore formation and integrated the metal-oxides crystals. Urea made the particles welly dispersed, and weakened the XRD peaks since it improved the melting process.