不同粒度煤气化渣的组成结构特征与烧失行为研究OA

This study systematically investigated the composition-structure characteristics and thermochemical behaviors of gasification slag with different particle sizes,aiming to elucidate the influence mechanism of particle size distribution on thermal stability and provide a theoretical founda-tion for the resource utilization of coal gasification slag.Through particle size classification of fixed-bed coal gasification slag(GS),eight progressively finer samples(GS00-GS200)were obtained.A combination of techniques including proximate analysis,ultimate analysis,XRD,SEM,and FTIR was employed to characterize the compositional and structural evolution across different particle frac-tions.Thermogravimetric analysis coupled with macrokinetic modeling was implemented to investi-gate thermal decomposition characteristics and dynamic parameters.The experimental results reveal that ash content exhibits a positive correlation with particle size,while fixed carbon demonstrates an inverse relationship.GS00 displays prominent Si—O—Si stretching vibrations in FTIR spectra and distinct SiO2 diffraction peaks in XRD patterns,indicating its higher silica content;morphological evo-lution shows a gradual reduction in bulk particle size with increasing classification severity,accompa-nied by predominant flocculent structures in finer fractions,suggesting effective preliminary separation of ash components from residual carbon through particle size screening.Thermochemical behavior analysis demonstrates that the maximum weight loss rate and total mass loss decrease significantly with increasing particle size.Notably,GS00 exhibits minimal mass loss(3.42%)and superior ther-mal stability.Under nitrogen atmosphere,all samples undergo intense decomposition between 580℃and 745℃.Kinetic analysis using reaction order models revealed optimal fitting(R＞0.969)with third-order reaction kinetics.Particularly,GS00 requires the highest activation energy(193.996 kJ/mol)under this reaction order,indicative of thermally stable compounds such as carbonates or aluminosili-cates.These findings suggest that the ash-rich fraction(GS00)possesses significant potential for molecular sieve synthesis applications due to its elevated silica content and exceptional thermal stability.