论文部分内容阅读
借助相分析中的偏提取方法对取自东太平洋莱恩群岛水下海山上的水成型铁锰结壳进行了选择性提取实验.结果显示,稀土元素在结壳中的富集归因于其中的矿物或氧化物而受环境影响较小,主要富集于无定形铁的氧化物/氢氧化物相中而只有少量存在于δ-MnO2中,显示出无定形铁的氧化物/氢氧化物比δ-MnO2对稀土元素具有更强的络合能力.虽然稀土元素在海水中主要是以碳酸盐络合物的形式存在,但是无定形铁的氧化物/氢氧化物则主要与海水中的自由稀土元素离子络合,而δ-MnO2则直接吸附稀土元素的碳酸盐络合物.铁锰结壳中的Ce正异常是由于结壳生长处底层流中活跃的可溶性氧把可溶性的Ce3+氧化成不溶性的Ce4+并且主要被无定形铁的氧化物/氢氧化物络合,而不是由δ-MnO2将可溶性的Ce3+氧化成不溶性的Ce4+而发生沉淀从而导致的Ce正异常.
Selective extraction of water-forming ferromanganese crusts from submarine seamounts in the Ryne Archipelago in the Eastern Pacific Ocean was carried out by means of partial extraction in phase analysis.The results show that the enrichment of rare earth elements in crusts is attributed to the mineral Or oxide with less environmental impact, mainly enriched in the amorphous iron oxide / hydroxide phase and only slightly in δ-MnO2, indicating that the amorphous iron oxide / hydroxide ratio δ -MnO2 has a stronger ability to complex rare earth elements.Although rare earth elements mainly exist in seawater as carbonate complexes, the oxides / hydroxides of amorphous iron are mainly related to the free Rare earth elements ion complexation, and δ-MnO2 directly adsorbed rare earth carbonate complexes.Fe ferromanganese crust in the Ce positive anomaly is due to the bottom of the crust growth of soluble oxygen in the bottom flow of soluble Ce3 + oxidation Into insoluble Ce4 + and is mainly complexed by oxides / hydroxides of amorphous iron, rather than being precipitated by the oxidation of soluble Ce3 + by soluble δ-MnO2 to insoluble Ce4 +, resulting in a positive Ce anomaly.