世界海洋结核结壳稀土成因初探

Concentration of REY in world polymetallic nodules and cobalt-rich crusts

大洋海底蕴藏着丰富的稀土矿产资源,包括深海富稀土软泥和多金属锰结核和富钴结壳。本文则关注了多金属锰结核和富钴结壳中的稀土元素的富集机制。作者首先统计了全世界范围内各重要海域的结核与结壳的稀土元素和钇(REY)的含量,发现重稀土和钇(HEY)在结核结壳中的比重普遍大于15%,而结核与结壳的稀土含量则普遍高于深海洋泥,其中结壳的稀土含量普遍高于结核。针对这类重要的稀土矿藏,作者以库克群岛为例,初步研究了稀土富集机制。分析认为,稀土元素与铁和磷酸盐的含量具有强相关性,且铁锰结核或结壳中的稀土很可能是主要通过胶状羟基氧化铁吸附而缓慢富集起来的。

There are abundant mineral rare earth resources on the ocean floor such as abyssal rare earth mud,polymetallic nodules and cobalt-rich crusts.This paper focuses on the concentration mechanism of rare earth elements（REE）in polymetallic nodules and cobalt-rich crusts.The authors firstly sum up the content of REE and yttrium（∑REY）in polymetallic nodules and cobalt-rich crusts all over the world,finding that the proportions of their heavy REE and yttrium（HEY）are completely higher than 15%.In addition,∑REY in polymetallic nodules and cobalt-rich crusts is generally higher that in abyssal REE-rich muds,and∑REY in crusts is generally higher than that in nodules.Taking Cook Islands as an example,we study the concentration mechanism of∑REY in such significant rare earth resources.Analysis shows that there are strong correlations between∑REY with Fe and P.Also,it is most likely that∑REY in polymetallic nodules and cobalt-rich crusts is slowly concentrated by means of the adsorption of iron oxyhydroxide colloid.