• 关键词：黄铁矿  碳酸盐  铊  相态分布  表面反应  释放  电感耦合等离子体质谱  漫反射红外光谱

• 基金项目：国家自然科学基金(No.20477007);广东省自然科学基金重点项目(No.36210);广州市属高校科技计划项目(No.62013)

• 张平
• 1. 广州大学广州发展研究所, 广州 510006; 2. 广州大学污染控制与同位素应用技术重点实验室, 广州 510006

• 杨春霞
• 广州大学污染控制与同位素应用技术重点实验室, 广州 510006

• 陈永亨
• 1. 广州大学广州发展研究所, 广州 510006; 2. 广州大学污染控制与同位素应用技术重点实验室, 广州 510006

• 彭平安
• 中国科学院有机地球化学国家重点实验室, 广州 510640

• 摘要：采用分级提取-电感耦合等离子体质谱法,对黄铁矿中铊的相态分布进行了考察.结果表明,黄铁矿中的铊主要以存在于硅酸盐相中和以酸可交换的形式存在于矿物结构中的铊为主,这部分铊分别占到58.3%和25.1%;以可氧化态形式结合在黄铁矿(FeS₂)中的铊次之,占11.2%;以易还原态形式存在于铁氧化物相中的铊最少,为5.4%.自然条件下铊的释放主要是酸可交换态铊和可氧化态铊的释放迁移过程.漫反射红外光谱表征发现,黄铁矿在表面氧化过程中其表面羟基增多,表明存在表面溶解及表面酸化现象.进一步的释放机理探讨认为,铊在黄铁矿表面存在一种“溶解-吸附沉淀”平衡,这一平衡由碳酸盐中和作用和黄铁矿表面氧化共同控制,并决定了铊的释放迁移.

• Abstract：Phase thallium in pyrite was analyzed by inductively coupled plasma mass spectrum (ICP-MS) with sequential extraction procedure. The results showed that thallium of pyrite existed mostly in silicate phase and mineral structure by acid-exchangeable state and the proportion were 58.3% and 25.1% respectively. Thallium existed less in pyrite (FeS₂) by oxidable state with 11.2%,and lest in iron oxides by reducible state with 5.4%.The release and migration behaviors of thallium in pyrite were mainly derived from acid-exchangeable and oxidable state thallium at natural environment. The surface reaction in pyrite was investigated by the diffuse reflectance FTIRspectroscopy (DRIFTS), and it was found that the surface hydroxyls in pyrite were strengthened in the process of surface oxidation; moreover, the surface dissolution and surface acidification were indicated. Athallium release mechanism was proposed that the dissolution-adsorption precipitation equilibrium was occurred, and the equilibrium was under the control of both neutralization reaction of carbonate and surface oxidation of pyrite, and finally decided the release and migration of thallium.

• Key words：pyrite  thallium  carbonate  phase of thallium  surface reaction  release  ICP-MS  diffuse reflectance FTIR spectroscopy

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