Weathering-induced Sb isotope fractionation during leaching of stibnite and formation of secondary Sb minerals

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F24%3A10136550" target="_blank" >RIV/00023272:_____/24:10136550 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0009254124003334" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0009254124003334</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemgeo.2024.122253" target="_blank" >10.1016/j.chemgeo.2024.122253</a>

Result language

angličtina

Original language name

Weathering-induced Sb isotope fractionation during leaching of stibnite and formation of secondary Sb minerals

Original language description

In this work, we investigated the extent of antimony (Sb) isotopic fractionation during weathering of stibnite at supergene conditions. Antimony isotope data have been obtained from secondary Sb minerals collected from Pezinok, Dobsina (both Slovakia) and Allchar (North Macedonia) deposits and mine tailings. The Sb isotope compositions of sulfides and secondary Sb minerals formed on the primary stibnite [Sb2S3] or in mine tailings grains were compared with each other. Furthermore, we experimentally investigated Sb isotope fractionation during stibnite leaching with different acids. Our study reveals a large isotopic range for delta Sb-123 (from -0.50 to +0.69 %o) for secondary Sb minerals. They are either isotopically indistinguishable or isotopically lighter than the primary stibnite. Isotopically indistinguishable weathering products likely formed by quantitative Sb transfer from stibnite to the secondary minerals, such as brandholzite [Mg(H2O)(6)[Sb(OH)(6)](2)] from Pezinok. Isotopic fractionation towards lighter delta 123Sb was observed for adsorption of Sb onto iron oxides. Distinctly isotopically lighter delta 123Sb was observed in secondary Sb minerals tripuhyite [FeSbO4], chapmanite [Fe-2(3+) Sb3+(Si2O5)O-3(OH)], hydroxyferroromeite [Fe2Sb2O6(OH)], and stibiconite [Sb3O6OH] that either replace stibnite or formed in mine tailings from the pore solutions. These secondary minerals were likely generated by partial precipitation of Sb from aqueous solutions produced by dissolution of stibnite. In the leaching experiments with HCl and oxalic acid, Sb was leached without significant isotope effects during the first 2-3 days, followed by a drop of the dissolved Sb concentration associated with Sb isotope fractionation towards high delta Sb-123 in the leachate (by up to 0.5 %o) after 4-7 days. We interpret these observations to be related to the precipitation of secondary Sb oxides with low delta Sb-123, resulting in an isotopically heavy dissolved Sb pool.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10504 - Mineralogy

Project

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Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Chemical Geology

ISSN

0009-2541

e-ISSN

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Volume of the periodical

662

Issue of the periodical within the volume

September

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

13

Pages from-to

1-13

UT code for WoS article

001265533600001

EID of the result in the Scopus database

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