Sustainable Mining and Metallurgy

The composition of biomass and coal is very complex, and these components jointly determine the sintering or slagging characteristics of ashes in the thermal conversion process of mixed biomass and coal, which has an important impact on the application and promotion of thermal conversion technology of the mixed biomass and coal. In this paper, typical biomass straw and bituminous coal were used as raw materials, and the influence of different mixing ratios, burning temperature and time on the sintering characteristics of the combustion ash of mixed biomass and coal was deeply studied. The results indicated that the higher the mixing ratio of corn stalk, the more obvious the deashing effect was. The ash content of rice straw mixed with bituminous coal was higher than that of corn straw mixed with bituminous coal, which was mainly caused by the different chemical compositions and structure of the two kinds of straw biomass. Under the same sintering temperature and biomass mixing ratio, the effect of sintering time on ash content was not obvious. With the increase of burning temperature, the lower the ash content of the mixed ash samples obtained from the thermal conversion of mixed corn straw and bituminous coal, the more obvious the ash removal effect. When the mixing proportion of corn straw increased from 25% to 75%, the ash morphology varied from irregular shape or honeycomb structure to obvious melting and bonding phenomenon. The slagging tendency of the mixed combustion ash was enhanced by the increase of the ignition temperature, while the effect of the burning time on the microstructure of the ash sample was small.