摘要
模拟水泥窑高温煅烧掺有Cd、Ni化学试剂的水泥生料,由制取的水泥熟料制备水泥净浆片.通过电子探针的点、线、面分析,研究了水泥净浆中Cd、Ni的整体分布和在不同矿物相中的具体分布特征.结果表明,Cd、Ni在水泥净浆中均出现了富集现象:元素分布图像显示Cd主要赋存于水化氢氧化钙(CH)晶体中,主要以Cd/Ca氢氧化物形式存在于水泥净浆中,线分析结果指出水化氢氧化钙(CH)晶体中Cd含量自晶体内部向外递减;面或点分析表明其它矿物相中Cd含量较低,其中点分析结果显示中间相中Cd浓度均低于1%.Ni富集区域面积都较小,元素分布图像和线分析结果都表明Ni与Mg的分布有着较好的一致性,主要形成Ni-Mg化合物,以独立矿物相形式随机分布于水泥净浆中;面或点分析表明其它水化产物中Ni含量较低,其中点分析结果显示中间相中Ni浓度均在1%左右.
Clinker acquired from a cement calcinations simulation of raw materials containing Cd and Ni chemical reagents were used to prepare cement paste.According to the electron probe microanalysis（EPMA） of point,line and surface analysis,the whole distribution situation of Cd and Ni in cement paste and the concrete distribution characters in different mineral phases were identified.The results show that,Cd and Ni both accumulate in the cement paste：the elemental distribution maps illustrate that Cd accumulates in the CH crystal,the main existing form of Cd in the cement paste is Cd/Ca hydroxides and the line analysis results further indicate that the Cd content in the CH crystal decreases gradually from the inside of the crystal to the outside;the surface and point analysis shows that the Cd content in other mineral phases is small,especially the point analysis results indicate that Cd concentration in middle phases is lower than 1%.The high concentration areas of Ni are all small,and the elemental distribution maps and the line analysis results both provide evidences that Ni and Mg have well correspondence in distribution,indicating that Ni is mainly existed as the Ni-Mg compound with independent random distribution in the cement paste;the surface and point analysis reveals that Ni content in other mineral phases is small,particularly the point analysis results indicate that the Ni concentration in middle phases is around 1%.
出处
《环境科学》
CAS
CSCD
北大核心
2011年第6期1825-1830,共6页
Environmental Science
基金
“十一五”国家科技支撑计划项目(2007BAC16B03,2006BAC02A19)
关键词
水泥窑
电子探针
重金属
分布
形态
cement kiln
electron probe microanalysis
heavy metal
distribution
speciation
