基于Rietveld方法的脱硫石膏晶须生长机理研究  

Growth Mechanism of Desulfurized Gypsum Whisker with Rietveld Method

作　　者：李亚茹 丁宏政 张小婷 汪潇 王继娜 苗蕾 LI Yaru;DING Hongzheng;ZHANG Xiaoting;WANG Xiao;WANG Jina;MIAO Lei(School of Chemistry and Materials Science,Henan University of Urban Construction,Pingdingshan 467036,Henan,China;School of Physical Science and Engineering,Guangxi University,Nanning 530004,Guanxi,China)

机构地区：[1]河南城建学院材料与化工学院,河南平顶山467036 [2]广西大学物理科学与工程学院,广西南宁530004

出　　处：《陶瓷学报》2024年第1期97-102,共6页Journal of Ceramics

基　　金：2022年度河南省高等学校重点科研项目(22B430007);河南城建学院2022年大学生创新创业训练计划项目(CX-X2022025)。

摘　　要：为了阐释水热环境下的脱硫石膏晶须(Calcium Sulfate Whisker,HH-CSWs)的生长机理,以提高脱硫石膏(Flue Gas Desulfurization,FGD)的高附加值利用,在120℃的硫酸溶液中,保温时间为60 min的水热条件下合成了大长径比半水硫酸钙晶须。通过Rietveld方法拟合精修了HH-CSW样品及脱硫石膏的XRD曲线。根据Rietveld拟合结果,建立了HH-CSW样品及脱硫石膏的结构模型。晶体结构模型对比分析结果表明,脱硫石膏与HH-CSW晶须的晶体结构存在着明显区别:一是在脱硫石膏结构中有六个Ca-O-S键和两个Ca-O-H键,在HH-CSW结构中有八个Ca-O-S键;二是脱硫石膏结构中有两个H_(2)O通道(分别沿c轴和a轴方向),而HH-CSW结构中只有一个H_(2)O通道。据此可以推断脱硫石膏水热制备HH-CSW的形成机理是脱硫石膏结构中两个Ca-O-H键断裂释放H_(2)O,并与S结合形成两个新的Ca-O-S键,沿c轴释放H_(2)O分子从而失去部分结晶水形成了HH-CSW,为制备大长径比脱硫石膏晶须提供理论依据。In order to explain the growth mechanism of desulphurized gypsum whisker in hydrothermal environment and improve its high value-added utilization,calcium sulfate whisker(HH-CSWs) was synthesized in sulfuric acid solution at 120 ℃ for 60 min under hydrothermal conditions.XRD curves of HH-CSW and desulfurized gypsum were fitted and refined by using Rietveld method.According to the Rietveld fitting results,the crystal structure model of HH-CSW and desulfurized gypsum was established.Their crystal structures are obviously different in two aspects.On one hand,there are 6Ca-O-S bonds and 2 Ca-O-H bonds in the desulfurized gypsum structure,while there are 8 Ca-O-S bonds in the HH-CSW structure.On the other hand,the desulfurized gypsum structure has two H_(2)O channels(along the c and a axes,respectively),whereas the HH-CSW structure has only one H_(2)O channel.It can be concluded that,the formation of HH-CSW prepared by using hydrothermal method in flue gas desulfurization(FGD) is through the two Ca-O-H bonds in the structure of desulphurized gypsum break to release H_(2)O and the combination with S to form two new Ca-O-S bonds,so as to release H_(2)O molecules along the c-axis and lose part of the crystalline water to form HH-CSW.This can be used as a theoretical basis for preparing desulfurized gypsum whisker with high ratio of length to diameter.

关 键 词：脱硫石膏 HH-CSW Rietveld拟合 晶体结构 

分 类 号：TQ174.75[化学工程—陶瓷工业]