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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10504 - Mineralogy

Projekt

—

Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Chemical Geology

ISSN

0009-2541

e-ISSN

—

Svazek periodika

662

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

13

Strana od-do

1-13

Kód UT WoS článku

001265533600001

EID výsledku v databázi Scopus

—