尧璟云-硅酸盐水泥硬化体中Pb的存在形态20071025.pdfVIP

硅酸盐水泥硬化体中 Pb 的存在形态 1，2 1，2 1，2 1，2 尧 云 ，白瑞英 ,余其俊 ，韦江雄 璟 （1.华南理工大学材料学院，2.华南理工大学特种功能材料教育部重点实验室，广州 510640 ） 摘要：以纯硅酸盐水泥为研究对象，采用改进的Tessier A 连续提取法，研究了硅酸盐水泥硬化体中 Pb 的存在形态。 结合 X-ray 衍射（XRD ）、扫描电镜/能谱（SEM/EDS）测试手段，分析了不同形态 Pb 在水泥水化产物中的分布。 结果表明, 随龄期不同,纯硅酸盐水泥中有效态 Pb 占Pb 总量的 2～4% ，主要以吸附和沉淀形式存在于颗粒表面；铁 锰氧化态 Pb 主要以包裹形式存在于水泥水化矿物 AFt 和 C-S-H 中，约占 6～10%；残渣态的比例达 84～88%，为 Pb 的主要分布形态。随龄期延长，铁锰氧化态逐渐向残渣态转变。 关键词：水泥；Pb ；化学形态；分布 中图分类号：X75 文献标识码：A 文章编号： Speciation of Pb in Hardened Portland Cement 1,2 1,2 1,2 1,2 Yao Jingyun ,Bai Ruiying ，YU Qijun ，Wei Jiangxiong (1.College of Materials Science and Engineering, 2.Key Laboratory of Specially Functional Materials of Ministry of Education, South China University of Technology, Guangzhou 510640, China) Abstract: In this paper, a modified Tessier’s sequential extraction procedure was employed to investigated the speciation of Pb in hardened portland cement. The fraction distribution of lead with different speciation in the hydration products was accessed by X-ray diffraction(XRD) and scanning electronic microscope with energy dispersive spectrometer(SEM/EDS). The results show that: according to age, the 2～4% of total Pb in Portland cement is potential active which is adsorbed and deposited in the surface of grain; Fe/Mn oxide bounded fraction is mainly included in the AFt 和 C-S-H and about 6～10% percentage of Pb; Residual fraction of Pb is about 84～88%, which is the predominant fraction. The Pb which was Fe/Mn oxide bounded would changed into residual fraction gradually. Keywords ：cement; Pb; chemistry Speciation ; distribution 0.引言 作用对重金属等有毒有害组分进行固化[2] 。水 目前，利用水泥窑