Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to analyze individual microspheres, 1–2 μm in size, located in coal char particles of Inertoid and Fusinoid/Solid morphological types. It was shown that PM_1–2 (where PM = inorganic particulate matter) is formed in the porous structure of the carbon matrix, which controls the microsphere size, from authigenic minerals that determine their composition. Depending on the contents of SiO₂, Al₂O₃, and FeO, the studied microspheres fall into various groups differing in mineral precursors. The precursor of the Group 1 microspheres with the specific composition of SiO₂ + Al₂O₃ > 95 wt % and FeO ≤ 1.5 wt % is NH₄–illite. Microspheres containing SiO₂ + Al₂O₃ < 95 wt % and FeO in increasing content amounts up to 4, 6, and 10 wt %, included in Group 2, Group 3, and Group 4, respectively, are formed from mixed-layer K–illite–montmorillonite minerals subjected to cationic substitution with iron, followed by the entry of Fe³⁺ in interlayer sites. Calcite, dolomite, gypsum, magnesite, rutile, and siderite are involved in the formation of Group 5 microspheres with a high content of Ca, Mg, Ti, or Fe. The significant part of PM_1–2 is represented by microspheres of Groups 2, 3, and 4 regardless of the type of coal char particles (62% for Inertoid ones and 75% for Fusinoid/Solid ones). About one-third of the microspheres for both char morphotypes refer to Group 5. Microspheres of Group 1 (8%) are located only in the Inertoid char particles, which results from the characteristic effect of the maceral–mineral composition of original coal. It has been suggested that Inertoid and Fusinoid/Solid char particles are formed from various macerals, semifusinite and fusinite, respectively. Due to the closed-cell structure, semifusinite contains noncation-exchanged NH₄–illite, the mineral precursor of microspheres with low contents of Fe, K, Na, and Mg. The fusinite structure allows cationic substitution in NH₄–illite with the formation of mixed-layer K–illite and montmorillonite, the mineral precursors of a significant part of PM_1–2.

中文翻译：

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扫描电子显微镜–能量色散X射线光谱法（SEM–EDS）分析不同形态的煤焦颗粒中的PM _1-2微球

扫描电子显微镜和能量色散X射线光谱法用于分析大小为1-2μm的单个微球，它们位于惰性和Fusinoid / Solid形态类型的煤焦颗粒中。结果表明，PM _1-2（其中PM =无机颗粒物）形成在碳基质的多孔结构中，该结构控制着确定其组成的自生矿物，从而控制了微球的尺寸。根据SiO ₂，Al ₂ O ₃和FeO的含量，所研究的微球分为矿物前体不同的各种组。具有特定组成SiO ₂ + Al ₂ O ₃的第1组微球的前体> 95 wt％且FeO≤1.5 wt％为NH ₄伊利石。由混合层形成分别包含在第2组，第3组和第4组中的包含SiO ₂ + Al ₂ O ₃ <95 wt％和FeO含量分别增加至4、6和10 wt％的微球体K-伊利石-蒙脱石矿物经过铁的阳离子取代，然后Fe ³⁺进入层间位点。方解石，白云石，石膏，菱镁矿，金红石和菱铁矿参与形成了高含量的Ca，Mg，Ti或Fe的第5组微球。_1-2号纸机的重要部分不论煤焦颗粒的类型如何（第2组，第3组和第4组的微球都代表）（惰性颗粒为62％，而熔融/固体颗粒为75％）。两种炭形态的微球约有三分之一属于第5组。第1组（8％）的微球仅位于Inertoid炭颗粒中，这是由原始煤的矿物-矿物组成的特征作用所致。有人提出，惰性化合物和Fusinoid /固体炭颗粒分别由各种显微材料，半熔融沸石和Fusinite形成。由于具有闭孔结构，半纤锌矿包含非阳离子交换的NH _4-伊利石，这是微球中Fe，K，Na和Mg含量低的矿物前体。方铁矿结构允许在NH _4中进行阳离子取代-伊利石，形成了混合层的K-伊利石和蒙脱石，这是PM _1-2的重要部分的矿物前体。