华南花岗岩风化壳中稀土的存在形态及迁移富集模式

本文从化学形态角度，确立了一个ＲＥ形态分析流程，得出风化壳中ＲＥ化学形态可分为活性态，Ｆｅ，Ａｌ共沉淀态及有机结合态３种，全风化层样品中ＲＥ多数以活性态为主，但平远Ｃ剖面ＲＥ却以有机结合态占大多数，活性态、有机结合态ＲＥ与粘土矿物关系密切，而Ｆｅ，Ａｌ共沉淀态的ＲＥ与粘土矿物关系不大，原岩溶出试验表明，ＲＥ在有机介质中的溶出量一般高于无机介质，ＲＥ最大可能是呈有机无机混配络离子迁移，迁移、富集过程是络合、水解、沉淀和吸附反应同时出现，反应受ｐＨ控制，本文初步建立了花岗岩风化壳中ＲＥ往下迁移、富集的模式。

Transforming and Accumulating Behaviors and Existing Species of REE in the Weathering Crust of Granites in South China

An analytical method of REE chemical speciation has been established andthree kinds of REE chemical species which are activated species,Fe-Al co-depositedspecies and organic binding species in the weathering crust of granites have been deter-mined in this paper. REE of specimens from complete weathering crust exists mainly inactivated species with the exception of REE from Section C of Pingyuan Mine which ex-ists mostly in organic binding species. Of the three REE chemical species, the activatedand the organic ones are closed related to clay minerals,but the Fe-Al co-depositedspecies of REE has no such relationship. By testing REE solvency from original rocks,ithas been proved that the amount of REE dissolved in organic media are larger than thatin inorganic media, REE transformed probably in mixed organic and inorganic co-ordi-nate complex ions. Complexing,hydrolysis, deposition and absorption of REE whichare controlled by pH value coexist in the process of REE taransformation and accumula-tion,A preliminary model of transformation and accumulation of REE in the weatheringcrust of granites has been proposed at the end of the paper.