黔西南高砷煤中砷赋存状态的XAFS和铁的Moessbauer谱研究

黔西南高砷煤中砷赋存状态的XAFS和铁的Moessbauer谱研究

丁振华1 2, 郑宝山1, RBFinkelmam3, H E Belkin3, 胡天斗4, 刘涛4

1. 上海交通大学环境科学与工程学院，上海 200240; 2. 中国科学院地球化学研究所，环境地球化学国家重点实验室，贵阳 550002; 3.NationalCenter,U.S.GeologicalSurvey,RestonVA20192,USA; 4. 中国科学院高能物理研究所，北京正负电子对撞机同步辐射实验室，北京 100039

收稿日期:2003-06-20 修回日期:2003-06-20 出版日期:2003-06-20 发布日期:2003-06-20

Application of XAFS and Mossbauer Spectroscopy in Studying the Mode of Occurrence of Arsenic and Iron in High-As Coals from Southwest Guizhou Province

DING Zhen-hua1 2, ZHENG Bao-shan1, R B Finkelmam3, H E Belkin3, HU Tian-dou4, LIU Tao4

1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemitry, Chinese Academy of Sciences, Guiyang 550002; 2. School of Environmental Science and Engineering, Shanghai Jiaotong University, Minhang 200240; 3. National Center, U.S. Geological Survey, Reston VA,20192 USA; 4. BEPC NL, Beijing 100039, China

Received:2003-06-20 Revised:2003-06-20 Online:2003-06-20 Published:2003-06-20

摘要/Abstract

摘要： 利用X射线吸收精细结构分析(XAFS）和铁的穆斯堡尔谱(Moessbauer)对黔西南高砷煤中砷和铁的存在形式进行了研究。研究发现，高砷煤中的砷主要以高价砷的形式存在，也有少量以As2O3、砷黄铁矿、砷硫化物的形式存在。除1个样品中的铁全部以顺磁性针铁矿或超顺磁性的针铁矿的形式存在外，其它样品中的Fe主要是黄铁矿中的Fe，约占全铁的60％－91％；其次是黄铁钾矾中的Fe，约占全铁的9％－40％。

Abstract: Some small coal mines in Southwest Guizhou Province have high arsenic content，sometimes up to 3.5％．The application of high As-bearing coals has ca used about 3，000 people in arsenic poisoning in several villages．Coal samples from endemic arsenosis areas have been analyzed with instrument neutron activation analysis(INAA)，X-ray absorption fine structure(XAFS)，and Mossbauer spectroscopy．The modes of occurrence of arsenic and iron in high As-coals are discussed．Arsenic has different modes of occurrence in different samples ． XAFS show that arsenic mainly exists in the form of As5+．The arsenic XANES spectra．with a main peak and a shou1der，indicate the presence of at least two different arsenic forms in each sample，with the possible exception of sample J1-As6-97A．The radial structure functions (RSFs)show one major peak at about 0.125 nm，corresponding to the As -O distance in the AsO43- anion unit，and a small peak at around 0.27 nm，corresponding to As2O3．For sample J1-As6-97A，the RSF peak at 0.125 nm is more intense ，and arsenate is the dominant species of arsenic．Except for sample J1-As6-97A，the Mossbauer spectra show that 60％～91％ of iron is in the form of pyrite．For sample J1-As6-97A all iron is present as paramagnetic or superparamagnetic goethite(α-FeOOH )．The results demonstrate that arsenic exists mainly in the form of high valence，while the As203 ，arsenic pyrite and other sulfides comprise only a small fraction．Iron exists mainly in the form of pyrite(60％～91％)and jarosite (9％～40％)with one exception where all iron is present as paramagnetic or superparamegnetic goethite(α—FeOOH)．The difference between XAFs results and Mossbauer spectra indicates that arsenic and iron initially existed in different forms．It should be emphasized that in interpreting the results of XAFs spectroscopy other analytical results should also be considered．

丁振华 , 郑宝山, RBFinkelmam, H E Belkin, 胡天斗, 刘涛. 黔西南高砷煤中砷赋存状态的XAFS和铁的Moessbauer谱研究[J]. J4.

DING Zhen-hua1 2, ZHENG Bao-shan1, R B Finkelmam3, H E Belkin3, HU Tian-dou4, LIU Tao4. Application of XAFS and Mossbauer Spectroscopy in Studying the Mode of Occurrence of Arsenic and Iron in High-As Coals from Southwest Guizhou Province[J]. J4.