【摘要】 通过选择性化学提取法,对太平洋结壳调查区海山上富钴结壳和基岩样品中稀土元素(REEs)进行分级提取实验,利用电感耦合等离子体质谱仪(ICP-MS)测定了稀土元素含量,建立了富钴结壳中稀土元素化学相态分析方法。结果表明,富钴结壳中稀土元素在各个化学相态中富集顺序为:铁氧化物相>锰氧化物相>残渣态>碳酸盐相>吸附态,稀土元素主要富集于铁氧化物相中,所占比例为70.2%~73.9%,回收率为94.8%~105.9%。这主要受控于富钴结壳中非晶态铁氧/氢氧化物矿物(Fe OOH)。在不同地质体中,稀土元素赋存状态存在显著差异。碳酸盐岩中,稀土元素主要富集于碳酸盐相中;玄武岩和磷块岩中,稀土元素主要富集于残渣态中;富钴结壳和多金属结核中,稀土元素主要富集于铁氧化物相中。在不同构造层富钴结壳中,新壳层中稀土元素主要赋存于铁氧化物相中,老壳层中稀土元素主要赋存于残渣态中,表明磷酸盐化作用对老壳层稀土元素的富集具有显著影响。更多还原

【Abstract】 Selective chemical extraction method was utilized to fractionally extract rare earth elements( REEs) in cobalt-rich crusts and bedrock samples from the Pacific survey area,and REEs concentrations were determined by inductively coupled plasma mass spectrometry( ICP-MS). A method was established for the chemical phases analysis of REEs in cobalt-rich crusts. The results showed that the REEs enrichment in different phases in cobalt-rich crusts conformed to the following order: iron oxide phase > manganese oxide phase > residual phase > carbonate phase > adsorbed phase. About 70. 2%- 73. 9% of total REEs contents were mainly enriched in the iron oxide phase and the recoveries were 94. 8%- 105. 9%. Therefore,most of REEs were controlled by amorphous Fe OOH minerals. In different geological bodies,occurrence phase of REEs had significant difference. REEs were mainly enriched in the carbonate phase in carbonate rock,the residual phase in basalt and phosphate rock,and the iron oxide phase in cobalt-rich crusts and polymetallic nodules. In different structural layer of cobalt-rich crusts,REEs in the new layer were mainly enriched in the iron oxide phase,and REEs in the old layer were mainly enriched in the residual phase. It suggested that phospharization played a more significant role on the REEs enrichment in the old layer.更多还原