| 常压盐溶液法转化脱硫石膏制备α-半水石膏的相变机理 |
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| 引用本文： | 吴晓琴,杨有余,裘建军.常压盐溶液法转化脱硫石膏制备α-半水石膏的相变机理[J].武汉冶金科技大学学报,2011(1):37-41. |
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| 作者姓名： | 吴晓琴 杨有余 裘建军 |
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| 作者单位： | 武汉科技大学化学工程与技术学院,湖北武汉430081 |
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| 基金项目： | 国家“863”计划资助项目（2006AA06Z385）; 武汉科技大学杰出青年基金资助项目（2008RC06） |
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| 摘 要： | 采用常压复合盐溶液水热法对钙基湿法烟气脱硫（FGD）工艺的副产品FGD石膏进行转化,以制备α-半水石膏。利用DSC/TG综合热分析、SEM和化学分析对转化后的石膏样品进行研究。结果表明,FGD石膏转化为α-半水石膏的过程遵循溶解-重结晶机理。在重结晶诱导期内,FGD石膏首先在热盐溶液中溶解,形成硫酸钙过饱和溶液,在一定的过饱和度区域内,α-半水石膏雏晶直接从溶液中析出,发生石膏晶体亚微观结构上的改变。随后石膏雏晶继续生长,形成了均匀粗大的棱柱状α-半水石膏晶体,实现结晶物质在各个晶体上的重新分布。
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| 关 键 词： | 脱硫石膏 α-半水石膏 复合盐溶液 石膏转化 相变 机理 |
Mechanism of α-calcium sulfate hemihydrate produced from FGD gypsum in thermal solution |
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| Authors: | Wu Xiaoqin Yang Youyu Qiu Jianjun |
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| Affiliation: | (College of Chemical Engineering and Technology,Wuhan University of Science and Technology,Wuhan 430081,China) |
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| Abstract: | α-calcium sulfate hemihydrate was produced from FGD gypsum converted in compound salt solution,and the hemihydrate sample was studied with DSC/TG thermal analysis,metallographic microscope and chemical analysis.The experiment shows that the transformation of FGD gypsum follows the dissolution and recrystallization mechanism.During the induced phase of conversion process,FGD gypsum forms supersaturated solution first,and young crystals of α-calcium sulfate hemihydrate precipitates within certain range of the solution supersaturated degree.With the change of submicroscopic structure of FGD gypsum crystal,the young crystals grow into even stubby prismy α-calcium sulfate hemihydrate crystal in short time.The matter redistribution of calcium sulfate is accomplished and the transformation of FGD gypsum completed. |
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| Keywords: | FGD gypsum α-calcium sulfate hemihydrate compound salt solution gypsum conversion phase transformation mechanism |
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