Combustion characteristics of spherical particles mixed with coal slime and sawdust

Abstract

ABSTRACT In the presence of N2/O2, a mixed sample of ShanXi Lvliang Lin Xian coal slime and sawdust was burned in a continuously weighed vertical tube furnace to study the influence of temperature and the sawdust mixing ratio on the combustion characteristics of the mixed sample. In addition, the sintering characteristics of the sample were investigated. An O2 and N2 ratio of 21%:79%, temperatures of 800°C, 850°C, 900°C, 950°C, and 1000°C, and sawdust mixed ratios of 5%, 10%, 15%, and 20% were used. Scanning electron microscopy (SEM), x-ray diffraction (XRD), and mercury intrusion porosimetry (MIP) analyses were performed on the combustion samples with a furnace at temperatures of 800°C, 900°C, and 1000°C for a mixing ratio of 20%. The results show that increasing the furnace temperature or increasing the proportion of sawdust accelerates the combustion of the mixed sample and shortens the ignition delay and burnout time. The combustion process of the dry mixed sample can be divided into four parts: sawdust volatile combustion, coal slime volatile combustion, sawdust fixed carbon combustion, and coal mud fixed carbon combustion. The test results show that at 800°C, the ash sample with a sawdust ratio of 20% was not sintered, while at 900°C and 1000°C, the ash samples with sawdust ratios of 20% were sintered.