铬离子在水泥硬化体中的迁移转换及再分配  

Transportation and Re-distribution of Addition Chromium in Hardened Portland Cement

作　　者：尧璟云[1,2] 余其俊[1,2] 韦江雄[1,2] 白瑞英[1,2] 

机构地区：[1]华南理工大学材料科学与工程学院,广州510640 [2]华南理工大学特种功能材料教育部重点实验室,广州510640

出　　处：《武汉理工大学学报》2009年第14期5-9,共5页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(50772038)

摘　　要：采用BCR连续浸提法,结合紫外-可见分光光度计和XRD等方法研究了不同掺量Cr在水泥硬化体中的形态分布。研究结果表明:外加水溶性Cr掺量从0增加到300 mg/kg时,其在水泥硬化体中主要以残渣态和可氧化态形式为主,达95%以上,可交换态含量在1%以内;随着水溶性Cr的加入,水泥硬化体中各形态Cr绝对含量均呈线性增加,其中,可氧化态增长最快,酸可提取态增加最慢,而残渣态Cr绝对含量虽然增加,但相对含量减少;同时随着外加Cr掺量的增加,Cr的形态再分配系数由1增加到1.35,其结合强度系数由0.94降低到0.84,说明Cr在水泥硬化体中的固化稳定性随可溶性Cr的掺量的增大而降低。XRD研究表明外加Cr离子优先富集在AFt中。The transportation and redistribution in hardened Portland cement with addition chromium were investigated by BCR Sequential extraction procedure, Ultraviolet, Visible Spectrophotometer and X-ray Diffraction. The results show that： （1） When the added soluble chromium vary from 0 to 300 mg·kg^-1, oxidizable and residue form are dominant fraction, account for beyond 95 %, acidic exchangeable form only take about 1% ; （2） the content of different chemical form chromium would be linear increase with the addition soluble chromium. Among these the content of oxidizable form increases fastest, and the acidic exchangeable form is the lest slowly, but the relative content of residue form reduces from 86.8 % to 67.4 % ; （3） While the addition chromium increasing, the redistribution index increase from 1 to 1.35 while the metal binding intensity index reduce from 0.94 to 0.84. These two indices indicate that the chromium would be in unstable form when addition soluble chromium in Portland cement. The X-ray Diffraction also proves that addition chromium will accumulate in AFt firstly.

关 键 词：铬 形态 再分配 迁移转换 水泥硬化体 

分 类 号：TQ172.1[化学工程—水泥工业]