Critical metals (REE, Sc, PGE) in Ni laterites from Cuba and the Dominican Republic
Critical metals (REE, Sc, PGE) in Ni laterites from Cuba and the Dominican Republic
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DOI：
10.1016/j.oregeorev.2015.10.010
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发表时间：
2016-03-01
影响因子：
3.3
通讯作者：
Durisova, Jana
中科院分区：
文献类型：
--
作者：
Aiglsperger, Thomas;Proenza, Joaquin A.;Durisova, Jana
镍红土被认为是重要金属（CM）勘探的重要目标，因为稀土元素（REE），Sc和铂族元素（PGE）可以在风化过程中富集，作为残留和次生富集的结果。本文提供了来自两种不同镍红土类型（i）古巴Moa Bay矿区（氧化物型）和（ii）多米尼加共和国Falcondo矿区（含水镁硅酸盐型）的CM的地球化学和矿物学数据。重点是检查他们的潜力，积累CM和所涉及的过程。结果表明，CM集中在特定区域的表面：（i）在粘土矿物丰富的层位和次生锰氧化物（S）的区域内的稀土元素，（ii）在富含次生铁和锰的氧化物（S）的区域内的Sc和（iii）在残留铬尖晶石和次生铁和锰的氧化物（S）的Ni红土剖面的上部水平的高浓度区的PGE。浓度因素涉及（一）残留富集强烈风化，（二）动员CM在不断变化的Eh和pH值条件下，随后再沉淀在有利的地球化学屏障和（三）生物圈和褐铁矿土壤之间的相互作用在最高水平的配置文件（关键区）与参与新生过程。与常规CM矿床相比，两种镍红土类型中CM的总含量较低，但具有经济意义，因为CM必须被视为Ni（+Co）生产过程中成本低廉的副产品。目前正在开发的创新提取方法被认为将提高镍红土作为未来非常规CM矿床的重要性。(C)2015 Elsevier B.V.版权所有。
Ni laterites are considered worthy targets for critical metals (CM) exploration as Rare Earth Elements (REE), Sc and platinum group elements (PGE) can be concentrated during weathering as a result of residual and secondary enrichment. In this contribution geochemical and mineralogical data of CM from two different nickel laterite types (i) from the Moa Bay mining area in Cuba (oxide type) and (ii) from the Falcondo mining area in the Dominican Republic (hydrous Mg silicate type) are presented. Emphasis is given on examining their potential to accumulate CM and on processes involved. Results show that CM are concentrated towards the surface in specific zones: (i) REE in clay minerals rich horizons and within zones composed of secondary Mn oxide(s), (ii) Sc within zones rich in secondary Fe and Mn bearing oxide(s) and (iii) PGE in zones with high concentrations of residual chromian spinel and secondary Fe and Mn bearing oxide(s) at upper levels of the Ni laterite profiles. Concentration factors involve (i) residual enrichment by intense weathering, (ii) mobilization of CM during changing Eh and pH conditions with subsequent reprecipitation at favourable geochemical barriers and (iii) interactions between biosphere and limonitic soils at highest levels of the profile (critical zone) with involved neoformation processes. Total contents of CM in both Ni laterite types are low when compared with conventional CM ore deposits but are of economic significance as CM have to be seen as cost inexpensive by-products during the Ni (+Co) production. Innovative extraction methods currently under development are believed to boost the significance of Ni laterites as future unconventional CM ore deposits. (C) 2015 Elsevier B.V. All rights reserved.