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| Ratie, G.; Garnier, J.; Calmels, D.; Vantelon, D.; Guimaraes, E.; Monvoisin, G.; Nouet, J.; Ponzevera, Emmanuel; Quantin, C.. |
| Ultramafic (UM) rocks are known to be nickel (Ni) rich and to weather quickly, which makes them a good candidate to look at the Ni isotope systematics during weathering processes at the Earth’s surface. The present study aims at identifying the Ni solid speciation and discussing the weathering processes that produce Ni isotope fractionation in two deep laterite profiles under tropical conditions (Barro Alto, Goiás State, Brazil). While phyllosilicates and to a lower extent goethite are the main Ni-bearing phases in the saprolitic part of the profile, iron (Fe) oxides dominate the Ni budget in the lateritic unit. Nickel isotopic composition (δ60Ni values) has been measured in each unit of the regolith, i.e., rock, saprock, saprolite and laterite (n=52).... |
| Tipo: Text |
Palavras-chave: Nickel cycle; Lateritic regolith; Nickel isotopes; XANES; Ultramafic environment; Weathering. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00436/54712/56149.pdf |
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| Ratie, G.; Quantin, C.; Jouvin, D.; Calmels, D.; Ettler, V.; Sivry, Y.; Cruz Vieira, L.; Ponzevera, Emmanuel; Garnier, J.. |
| Nickel isotope ratios were measured in ores, fly ash, slags and FeNi samples from two metallurgical plants located in the Goiás State, Brazil (Barro Alto, Niquelândia). This allowed investigating the mass-dependent fractionation of Ni isotopes during the Ni-laterite ore smelting and refining. Feeding material exhibits a large range of δ60Ni values (from 0.02 ± 0.10 ‰ to 0.20 ± 0.05 ‰, n=7), explained by the diversity of Ni-bearing phases, and the average of δ60Nifeeding materials was found equal to 0.08 ± 0.08‰ (2SD, n=7). Both δ60Ni values of fly ash (δ60Ni = 0.07 ± 0.07‰, n=10) and final FeNi produced (0.05 ± 0.02 ‰, n=2) were not significantly different from the feeding materials ones. These values are consistent with the very high production yield of... |
| Tipo: Text |
Palavras-chave: Nickel; Isotope; Smelting; Refining; Source; Soil. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00278/38961/37501.pdf |
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| Ratie, G.; Jouvin, D.; Garnier, Julien; Rouxel, Olivier; Miska, S.; Guimaraes, E.; Cruz Vieira, L.; Sivry, Y.; Zelano, I.; Montarges-pelletier, E.; Thil, F.; Quantin, C.. |
| Although Ni isotopes have been shown to be significantly fractionated in terrestrial samples, their use in continental environmental studies has not yet been evaluated. The present study focuses on an ultramafic (UM) massif (Barro Alto, Goias, Brazil) because such areas are naturally rich in Ni. We present developed lateritic weathering profiles. The goal of the study is to evaluate the potential of using Ni isotopes in environmental continental studies by combining its isotopic signature with mineralogy, in order to better understand the geochemical cycling of Ni in UM settings during weathering. As such, Ni isotope values were measured in samples from the Barro Alto UM complex in the main stages of the lateritic weathering profile of UM rocks, including... |
| Tipo: Text |
Palavras-chave: Nickel; Isotope; Weathering; Mineralogy; Soil. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36553/35098.pdf |
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| Ratie, G.; Quantin, C.; Maia De Freitas, A.; Echevarria, G.; Ponzevera, Emmanuel; Garnier, J.. |
| Ultramafic derived soils are characterized by low nutrient soils, a low Ca:Mg ratio, and high metal contents such as Ni, Co and Cr. The vegetation growing on these soils is highly adapted and includes both Ni hyperaccumulator and accumulator species. Today, approximately 530 Ni hyperaccumulator species are listed worldwide and the Ni concentration can be extremely high, e.g. up to 25% in latex from Pycnandra acuminata (Sapotaceae), a tree found in New Caledonia. The aim of this study is to identify the potential role of Ni hyperaccumulator plants in the Ni biogeochemical cycle at the soil surface by using Ni isotopes. A set of Ni hyperaccumulator and Ni accumulator plants as well as topsoils were sampled on the Barro Alto and Niquelândia ultramafic... |
| Tipo: Text |
Palavras-chave: Nickel; Isotope; Ni hyperaccumulator species; Ultramafic environment. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00464/57565/59740.pdf |
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