Abstract

Glassy slag of CaO–SiO₂–FeO_x systems is an important mineral phase of steelmaking slag when being used as a fertilizer for paddy fields, because this glassy phase can easily dissolve Fe and can stabilize hydrogen sulfide and suppresses over reduction. Structural analysis using Raman spectroscopy and ²⁹Si NMR was performed to clarify the mechanism of dissolution of the glassy slag of CaO–SiO₂–FeO_x systems in aqueous solutions, similar to the soil conditions of a paddy field. These results were then compared to the leaching results reported previously. The structural unit of SiO₄ tetrahedra in the glassy oxide showed a decrease in the fraction of Q² and Q³ and an increase in the fraction of Q⁰ and Q¹ with increasing basicity and FeO content. Both the Raman and NMR spectra showed a significant decrease in Q⁰ and Q¹ peaks after leaching, indicating that the Q⁰ and Q¹ in the glassy slag were selectively dissolved. A comparison between the average number of bridging oxygens measured by Raman spectroscopy and the amount calculated by composition showed that a deviation occurs and increases when the basicity and FeO content are high. Based on this, it was assumed that some FeO started to bond to bridging oxygens.

Graphical Abstract

中文翻译：

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玻璃结构对CaO-SiO 2 -FeOx系统玻璃渣中Fe溶解行为的影响

摘要

CaO-SiO ₂ -FeO _x系统的玻璃渣是炼钢炉渣的重要矿物相，当用作稻田肥料时，因为该玻璃态相易于溶解Fe，可以稳定硫化氢并抑制过度还原。使用拉曼光谱和²⁹ Si NMR进行结构分析，以阐明CaO-SiO ₂ -FeO _x系统的玻璃状炉渣在水溶液中的溶解机理，类似于稻田的土壤条件。然后将这些结果与先前报道的浸出结果进行比较。玻璃态氧化物中SiO ₄四面体的结构单元表明Q ²的分数降低和Q ³和增加的比例Q ⁰和Q ¹随碱度和FeO含量。浸出后，拉曼光谱和NMR光谱均显示Q ⁰和Q ¹峰显着下降，表明玻璃渣中的Q ⁰和Q ¹被选择性溶解。通过拉曼光谱法测量的平均桥连氧的数量与通过组成计算的量的比较表明，当碱度和FeO含量高时，会出现偏差并增加偏差。基于此，可以认为某些FeO开始键合到桥接氧上。

图形概要