Prediction and observation of formation of Ca–Mg arsenates in
acidic and alkaline fluids: Thermodynamic properties and
mineral assemblages at Jáchymov, Czech Republic and Rotgülden,
Austria

J 2021

Prediction and observation of formation of Ca–Mg arsenates in acidic and alkaline fluids: Thermodynamic properties and mineral assemblages at Jáchymov, Czech Republic and Rotgülden, Austria

MAJZLAN, Juraj; Jakub PLÁŠIL; Edgar DACHS; Artur BENISEK; Stefan MANGOLD et. al.

Základní údaje

Originální název

Prediction and observation of formation of Ca–Mg arsenates in acidic and alkaline fluids: Thermodynamic properties and mineral assemblages at Jáchymov, Czech Republic and Rotgülden, Austria

Autoři

MAJZLAN, Juraj; Jakub PLÁŠIL; Edgar DACHS; Artur BENISEK; Stefan MANGOLD; Radek ŠKODA a Natalya ABROSIMOVA

Vydání

Chemical Geology, Amsterdam, Elsevier, 2021, 0009-2541

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Nizozemské království

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 4.685

Kód RIV

RIV/00216224:14310/21:00120912

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1016/j.chemgeo.2020.119922

UT WoS

000600546500036

EID Scopus

2-s2.0-85092744064

Klíčová slova anglicky

Thermodynamics; Calcium arsenates; Magnesium arsenates; Saturation; Solubility

Štítky

14315010, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 22. 1. 2021 10:27, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

The underground spaces of the former mines in Jachymov, Czech Republic and Rotgulden, Austria house diverse assemblages of secondary minerals, mostly arsenates. The formation conditions and processes involved with the secondary minerals were deciphered using field observations, sampling of both solids and co-existing aqueous solutions, calorimetric measurements on Ca-Mg arsenates, forward thermodynamic modeling, and X-ray absorption spectroscopy. In Jachymov, the sampled solutions have pH values from 0.3 up to 7.4 and are moderately to strongly oxidized. The acidic solutions precipitate arsenolite and kaatialaite, and originate by the weathering of native arsenic and sulfides. When these solutions encounter hydrothermal carbonates they are slowly neutralized and precipitate the Ca-Mg arsenates picropharmacolite, pharmacolite, haidingerite, brassite, and rosslerite. Measured enthalpies of formation and standard entropies were combined to Gibbs free energies of formation (all in kJ/mol) for picropharmacolite [Ca4Mg(AsO3OH)(2)(AsO4)(2 center dot)11H(2)O, - 8139.2 +/- 12.4], pharmacolite [Ca(AsO3OH)center dot 2H(2)O, - 1762.0 +/- 3.1], haidingerite [Ca(AsO3OH)center dot H2O, - 1522.8 +/- 3.1], rosslerite [Mg(AsO3OH)center dot 7H(2)O, - 2849.7 +/- 2.5], and brassite [Mg(AsO3OH)center dot 4H(2)O, - 2139.9 +/- 2.7]. Forward thermodynamic modeling and the calculation of temperature-relative humidity phase diagrams using these values agreed with field observations. In Rotgulden, secondary Ca-Mg minerals are restricted to gypsum and hornesite, and no aqueous solutions were sampled there. The Mg arsenates brassite and rosslerite are typical for systems which initially develop substantial acidity and metal load in the aqueous phase, and afterwards are neutralized, whereas the Mg arsenate hornesite is typical for systems which maintain circumneutral or mildly basic pH, and are slowly enriched in As. Evaluation of the saturation indices in almost 900 chemical analyses of pristine water and acidic/neutral mine drainage showed that they are all undersaturated with respect to Ca-Mg arsenates. Therefore, these minerals control the As solubility only in specific (carbonate-rich, Fe-poor, S-poor) mine drainage systems that are progressively neutralized.

Citovat

MAJZLAN, Juraj; Jakub PLÁŠIL; Edgar DACHS; Artur BENISEK; Stefan MANGOLD; Radek ŠKODA a Natalya ABROSIMOVA. Prediction and observation of formation of Ca–Mg arsenates in acidic and alkaline fluids: Thermodynamic properties and mineral assemblages at Jáchymov, Czech Republic and Rotgülden, Austria. Chemical Geology. Amsterdam: Elsevier, 2021, roč. 559, January 2021, s. 1-15. ISSN 0009-2541. Dostupné z: https://doi.org/10.1016/j.chemgeo.2020.119922.

@article{1719217,
   author = {Majzlan, Juraj and Plášil, Jakub and Dachs, Edgar and Benisek, Artur and Mangold, Stefan and Škoda, Radek and Abrosimova, Natalya},
   article_location = {Amsterdam},
   article_number = {January 2021},
   doi = {https://doi.org/10.1016/j.chemgeo.2020.119922},
   keywords = {Thermodynamics; Calcium arsenates; Magnesium arsenates; Saturation; Solubility},
   language = {eng},
   issn = {0009-2541},
   journal = {Chemical Geology},
   title = {Prediction and observation of formation of Ca–Mg arsenates in acidic and alkaline fluids: Thermodynamic properties and mineral assemblages at Jáchymov, Czech Republic and Rotgülden, Austria},
   url = {https://doi.org/10.1016/j.chemgeo.2020.119922},
   volume = {559},
   year = {2021}
}

TY  - JOUR
ID  - 1719217
AU  - Majzlan, Juraj - Plášil, Jakub - Dachs, Edgar - Benisek, Artur - Mangold, Stefan - Škoda, Radek - Abrosimova, Natalya
PY  - 2021
TI  - Prediction and observation of formation of Ca–Mg arsenates in acidic and alkaline fluids: Thermodynamic properties and mineral assemblages at Jáchymov, Czech Republic and Rotgülden, Austria
JF  - Chemical Geology
VL  - 559
IS  - January 2021
SP  - 1-15
EP  - 1-15
PB  - Elsevier
SN  - 00092541
KW  - Thermodynamics
KW  - Calcium arsenates
KW  - Magnesium arsenates
KW  - Saturation
KW  - Solubility
UR  - https://doi.org/10.1016/j.chemgeo.2020.119922
L2  - https://doi.org/10.1016/j.chemgeo.2020.119922
N2  - The underground spaces of the former mines in Jachymov, Czech Republic and Rotgulden, Austria house diverse assemblages of secondary minerals, mostly arsenates. The formation conditions and processes involved with the secondary minerals were deciphered using field observations, sampling of both solids and co-existing aqueous solutions, calorimetric measurements on Ca-Mg arsenates, forward thermodynamic modeling, and X-ray absorption spectroscopy. In Jachymov, the sampled solutions have pH values from 0.3 up to 7.4 and are moderately to strongly oxidized. The acidic solutions precipitate arsenolite and kaatialaite, and originate by the weathering of native arsenic and sulfides. When these solutions encounter hydrothermal carbonates they are slowly neutralized and precipitate the Ca-Mg arsenates picropharmacolite, pharmacolite, haidingerite, brassite, and rosslerite. Measured enthalpies of formation and standard entropies were combined to Gibbs free energies of formation (all in kJ/mol) for picropharmacolite [Ca4Mg(AsO3OH)(2)(AsO4)(2 center dot)11H(2)O, - 8139.2 +/- 12.4], pharmacolite [Ca(AsO3OH)center dot 2H(2)O, - 1762.0 +/- 3.1], haidingerite [Ca(AsO3OH)center dot H2O, - 1522.8 +/- 3.1], rosslerite [Mg(AsO3OH)center dot 7H(2)O, - 2849.7 +/- 2.5], and brassite [Mg(AsO3OH)center dot 4H(2)O, - 2139.9 +/- 2.7]. Forward thermodynamic modeling and the calculation of temperature-relative humidity phase diagrams using these values agreed with field observations. In Rotgulden, secondary Ca-Mg minerals are restricted to gypsum and hornesite, and no aqueous solutions were sampled there. The Mg arsenates brassite and rosslerite are typical for systems which initially develop substantial acidity and metal load in the aqueous phase, and afterwards are neutralized, whereas the Mg arsenate hornesite is typical for systems which maintain circumneutral or mildly basic pH, and are slowly enriched in As. Evaluation of the saturation indices in almost 900 chemical analyses of pristine water and acidic/neutral mine drainage showed that they are all undersaturated with respect to Ca-Mg arsenates. Therefore, these minerals control the As solubility only in specific (carbonate-rich, Fe-poor, S-poor) mine drainage systems that are progressively neutralized.
ER  -

MAJZLAN, Juraj; Jakub PLÁŠIL; Edgar DACHS; Artur BENISEK; Stefan MANGOLD; Radek ŠKODA a Natalya ABROSIMOVA. Prediction and observation of formation of Ca–Mg arsenates in acidic and alkaline fluids: Thermodynamic properties and mineral assemblages at Jáchymov, Czech Republic and Rotgülden, Austria. \textit{Chemical Geology}. Amsterdam: Elsevier, 2021, roč.~559, January 2021, s.~1-15. ISSN~0009-2541. Dostupné z: https://doi.org/10.1016/j.chemgeo.2020.119922.

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