Effect of biomass ashes on sintering characteristics of high/low melting bituminous coal ash

In this study, the effects of two biomass ashes (corn stalk (CS) and wood pellet (WP)) on the sintering behaviors of two types of coal (high melting Shanxi coal (SX) and low melting Shenhua coal (SH)) were investigated in a horizontal chamber furnace. The results show that CS 10%, CS 50%, and WP 10% promote the ash sintering of SX coal ash and SH coal ash, while WP 50% inhibits the sintering of SH coal ash. The higher blend ratio of CS ash strengthens the promoting effects on sintering of both coals. According to the results of SEM-EDX and XRD, the low blend ratio of biomass ash has limited influence on chemical compositions and minerals distribution of SX ash. Anorthite and low melting albite generate after adding 50% CS, which promotes the sintering of SX ash. 50% WP promotes the conversion of mullite to anorthite and gehlenite of SX ash by significantly increasing the content of calcium. CS ash promotes SH ash sintering by accelerating the formation of diopside and amorphous minerals. XRD analysis revealed that the calcium plays a vital role during the sintering of high blend ratio of WP.