Fine slag (FS) is an unavoidable by-product of coal gasification. FS, which is a simple heap of solid waste left in the open air, easily causes environmental pollution and has a low resource utilization rate, thereby restricting the development of energy-saving coal gasification technologies. The multiscale analysis of FS performed in this study indicates typical grain size distribution, composition, crystalline structure, and chemical bonding characteristics. The FS primarily contained inorganic and carbon components (dry bases) and exhibited a "three-peak distribution" of the grain size and regular spheroidal as well as irregular shapes. The irregular particles were mainly adsorbed onto the structure and had a dense distribution and multiple pores and folds. The carbon constituents were primarily amorphous in structure, with a certain degree of order and active sites. C 1s XPS spectrum indicated the presence of C–C and C–H bonds and numerous aromatic structures. The inorganic components, constituting 90% of the total sample, were primarily silicon, aluminum, iron, and calcium. The inorganic components contained Si–O-Si, Si–O–Al, Si–O, SO₄²⁻, and Fe–O bonds. Fe 2p XPS spectrum could be deconvoluted into Fe 2p_1/2 and Fe 2p_3/2 peaks and satellite peaks, while Fe existed mainly in the form of Fe(III). The findings of this study will be beneficial in resource utilization and formation mechanism of fine slag in future.

细渣（FS）是煤气化过程中不可避免的副产品。 FS是一种简单的露天堆放固体废物，易造成环境污染，资源利用率低，制约了节能型煤气化技术的发展。本研究中进行的 FS 多尺度分析表明了典型的晶粒尺寸分布、成分、晶体结构和化学键合特征。 FS主要含有无机和碳成分（干基），并表现出晶粒尺寸的“三峰分布”和规则的球状以及不规则的形状。不规则颗粒主要吸附在结构上，分布密集，孔隙和褶皱较多。碳成分主要是无定形结构，具有一定程度的有序性和活性位点。 C 1 s XPS 光谱表明存在 C-C 和 C-H 键以及许多芳香结构。无机成分占样品总量的90%，主要是硅、铝、铁和钙。无机成分含有Si-O-Si、Si-O-Al、Si-O、SO ₄ ^2-和Fe-O 键。 Fe 2 p XPS谱图可以解卷积成Fe 2 p _1/2和Fe 2 p _3/2峰以及卫星峰，而Fe主要以Fe(III)的形式存在。本研究的结果对于今后的资源利用和细渣形成机制的研究具有重要意义。