Physico-Chemical Characteristics and Mineral Transformation Behavior of Ashes from Crop Straw

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• 作者：Youqing Wu ; Shiyong Wu ; Ye Li ; Jinsheng Gao
• 刊名：Energy & Fuels
• 出版年：2009
• 出版时间：October 15, 2009
• 年：2009
• 卷：23
• 期：10
• 页码：5144-5150
• 全文大小：906K
• 年卷期：v.23,no.10(October 15, 2009)
• ISSN：1520-5029

文摘

In this paper, the physicochemical characteristics and mineral transformation behavior of three crop straw ashes (rice straw, wheat straw, and cotton straw) were investigated using ICP-AES, XRF, SEM-EDS, XRD, and ash fusion point analyzer. It was found that these ashes had quite high content of alkali metals (especially K) and quite low fusion point (especially cotton straw ashes) and caused easily the corrosion, slagging, and fouling of equipments. These straw ash particles were uniformly distributed in the small, medium, and large size. As the ashing temperature increased, some amounts of K (in the form of KCl) were released into the gas phase, quartz transformed to cristobalite and then keatite, and some mineral components also occurred to transform. Up to 1088 K, K₂O and Na₂O separately reacted with Al₂O₃ and SiO₂ to produce albite (K−Al−Si) and sanidine (Na−Al−Si). Above 1273 K, other alkaline earth oxides also participated in the above reactions to form amorphous matters like augite. Meanwhile, comprehensive utilization of crop straw ashes is also worth our attention, due to their special compositions.