Composition and structural properties of coal gasification fine slag and its classified products – a case study.

Coal gasification fine slag (CGFS) is a large solid waste in the field of coal chemical industry, and its land occupation and environmental pollution caused by stockpiling and landfill make its comprehensive utilization imminent. The composition and structure of CGFS is the basis of its resource utilization, particle size classification and density classification is the important means to achieve the separation and enrichment of components in CGFS, while there are significant differences in the properties of CGFS in different particle size and different density fractions. Therefore, a CGFS sample from Shaanxi, China was used as an example in this paper, and X-ray diffraction analyzer (XRD), X-ray fluorescence spectrometry (XRF), Fourier Transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and low-temperature N2 adsorption tester were applied to comprehensively analyze the compositional and structural properties of the raw as well as the graded (both size-graded and density-graded) samples. The results show that the proximate composition, mineral composition, elemental composition, surface functional groups, apparent morphology, and pore structure show a good regularity with the particle size and density of the samples. Meanwhile, these properties and their variations with particle size and density were analyzed for their implication in the separation of components and resource utilizations of CGFS. The findings of this study provide ideas and data support for large-scale dissipation and high value-added disposal of CGFS. [ABSTRACT FROM AUTHOR]