滇东地区中-高硫煤中放射性元素铀的地球化学特征

以滇东部分地区中-高硫煤为研究对象，利用高分辨率电感耦合等离子质谱(HR ICP-MS)对煤中铀进行测试，采用逐级提取实验分析了其中铀的赋存状态，研究了铀与形态硫、灰分、挥发分等煤质参数之间的相关性,探讨了煤中铀的分布规律与赋存状态并分析了其富集成因。结果表明：滇东地区中-高硫煤中铀均值为4.47 μg/g，高硫煤中铀的含量要高于中硫煤，用浓集系数判别大部分煤样都属于铀富集型。煤中铀多以有机结合态为主。煤中铀的相对富集是成煤时期沉积环境的氧化环境以及部分煤样发生的铀矿化和海水的影响、沉积火山灰共同作用的结果。

Geochemical characteristics of uranium in medium to high sulfur coals from Eastern Yunnan,China

High-resolution inductively coupled plasma mass spectrometry (HR ICP-MS) was used to measure the uranium concentration in medium-high sulfur coals from eastern Yunnan,China.Sequential chemical extraction procedures were adopted to investigate the mode of occurrence of uranium in studied coals.Correlation analysis was taken to study the relationship among uranium and different sulfur forms,ash yield,and volatile matter.The results show that in the coals from eastern Yunnan,uranium varies from 0.54 to 8.28 μg/g,with an average value of 4.47 μg/g.The uranium concentration in high sulfur coals is higher than that in medium sulfur coals.Some studied coals are uranium enriched with respect to concentration coefficient.Uranium is mainly associated with organic matter in the coals from eastern Yunnan,China.The causes of uranium enrichment are the oxidation environment during sedimentary period,uranium mineralization in some coals,marine transgression and regression,and the deposition of volcanic ash.