In this paper, the fusibility of biomass ashes with varying chemical and mineral compositions were investigated and their mineral phase transformations were characterised in-situ by using the HT-XRD technique. Results showed that ash fusion temperatures (AFTs) of the analysed biomass increased in the order of walnut shell (WS) < wheat straw (WHS) < peanut shell (PES) < pine sawdust (PS). This is attributed partially to their chemical compositions, since WS and WHS ashes had high K₂O contents (30.77%), but the PES and PS ashes were abundant in SiO₂, Al₂O₃ and/or CaO. HT-XRD analysis showed that K-bearing minerals were firstly identified but then diminished in WS ash as temperature, confirming their role for slag formation. For WHS ash, the release of KCl and the formation of K silicates or aluminosilicate at different temperatures were confirmed, leading consequently to a decreased AFTs. In the PES ash, SiO₂, MgO, CaAl₂Si₂O₈, CaAl₂SiO₆ were identified, which also did not melt at the temperatures examined. Likewise, minerals in PS ash including CaO, Ca₃SiO₅ and Ca₂SiO₄ remain identified at elevated temperatures. Macro- and micro-morphological analysis shows that the WS and WHS ashes were prone to be sintered at temperatures as low as 650 °C, yet PES and PS ashes were less sintered even at 850 °C. These were confirmed by thermodynamic calculations when the phase and mineral transitions were considered. These mineral phases were also compared with those from conventional XRD, confirming the advantages of HT-XRD in determining mineral phase transformation and comprehending fusibility of the biomass ashes.

在本文中，研究了具有不同化学和矿物成分的生物质灰的可熔性，并使用 HT-XRD 技术对其矿物相变进行了原位表征。结果表明，所分析生物质的灰熔化温度 (AFT) 按核桃壳 (WS) < 麦秸 (WHS) < 花生壳 (PES) < 松木屑 (PS) 的顺序增加。这部分归因于它们的化学成分，因为 WS 和 WHS 灰具有高 K ₂ O 含量 (30.77%)，而 PES 和 PS 灰富含 SiO ₂、Al ₂ O ₃和/或氧化钙。HT-XRD 分析表明，首先鉴定出含钾矿物，但随后随着温度的升高在 WS 灰分中减少，证实了它们在熔渣形成中的作用。对于 WHS 灰分，确认了在不同温度下 KCl 的释放和硅酸钾或硅铝酸盐的形成，从而导致 AFT 降低。在 PES 灰分中，鉴定出 SiO ₂ 、MgO、CaAl ₂ Si ₂ O ₈、CaAl ₂ SiO ₆，它们在检测的温度下也不熔化。同样，PS 灰中的矿物质包括 CaO、Ca ₃ SiO ₅和 Ca ₂ SiO ₄在高温下仍能识别。宏观和微观形态分析表明，WS 和 WHS 灰烬在低至 650 °C 的温度下易于烧结，而 PES 和 PS 灰烬即使在 850 °C 下也不易烧结。当考虑相变和矿物转变时，这些通过热力学计算得到证实。还将这些矿物相与传统XRD 的矿物相进行了比较，证实了 HT-XRD 在确定矿物相变和理解生物质灰的可熔性方面的优势。