A study on the interaction between ferric ion and silicic acid in hydrosphere: Si-containing ferruginous deposits formed in neutral hot spring waters  

作　　者：Gaowa Naren Akane Miyazaki Motoyuki Matsuo BAI Shuqin Kotaro Yonesu Yoshihiro Okaue Takushi Yokoyama 

机构地区：[1]Department of Chemistry, Faculty of Science, Kyushu University [2]Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University [3]Department of Chemistry, Graduate School of Arts and Sciences, University of Tokyo [4]College of Environment and Resources, Inner Mongolia University [5]Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University

出　　处：《Chinese Journal Of Geochemistry》2013年第1期27-34,共8页中国地球化学学报

基　　金：financially supported by the Interdisciplinary Programs in Education and the Projects in Research Development, Kyushu University

摘　　要：Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), infrared (IR) spectroscopy, powder X-ray diffraction (XRD), and 57Fe Mssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite (12), but apparently close to those of siliceous ferrihydrite (0.250.5). Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio proposed by Henmi et al. (1981), all the deposits in this study were concluded to be mixtures of various siliceous ferri-hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring waters, the formation conditions of siliceous ferrihydrite were also discussed.Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis （DTA）, infra- red （IR） spectroscopy, powder X-ray diffraction （XRD）, and 57Fe M6ssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite （1-2）, but apparently close to those of siliceous ferrihydrite （0.25-0.5）. Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio pro- posed by Henmi et al. （1981）, all the deposits in this study were concluded to be mixtures of various siliceous ferri- hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring wa- ters, the formation conditions of siliceous ferrihydrite were also discussed.

关 键 词：温泉水 硅酸盐 三价铁离子 SI 相互作用 中性 铁质 伸缩振动频率 

分 类 号：P641.3[天文地球—地质矿产勘探] P314.1[天文地球—地质学]