REE Speciation in Fluoride-Carbonate-Chloride Cooling Hydrothermal Fluids in the Presence of Barite and Celestine (Thermodynamic Modeling)

Author:

Shironosova Galina1ORCID,Prokopyev Ilya2ORCID

Affiliation:

1. Sobolev Institute of Geology and Mineralogy. Siberian Branch of the Russian Academy of Sciences

2. Novosibirsk State University

Abstract

A thermodynamic study was carried out in order to determine the forms of transport for the entire series of lanthanides and their ratio with changing parameters of a hydrothermal fluid of moderate concentrations of chloride, carbonate and fluoride components. Hydrothermal solution, cooling from 500 to 100 ∘C, affected barite and celestine, which are used as a source of sulfate sulfur, monazite as a source of rare earth elements (REE) and phosphorus, and calcite as a source of calcium. It has been established that, under weakly acidic (pH about 4.1) conditions, the equilibrium mineral association is represented by rare earth fluorite, monazite, rare earth fluorapatite, and strontiobarite. In the high-temperature region for light and medium REE, the leading is the first chlorocomplex LnCl+2. For heavy REE, the second fluorine complex LnF+2 takes the first place, except for terbium and dysprosium, for which a sharp predominance of the sulfate complex is revealed. A special picture is observed at 100 ∘C: the leading position is occupied by Ln+3 for both light and heavy REE. In the case of a near neutral weakly alkaline fluid (pH about 7.1), the equilibrium mineral association is represented by calcite, monazite, REE-fluorite, REE-fluorapatite, strontiobarite, and strontianite. The appearance of the latter in natural associations may serve as an indication of the increased alkalinity of the ore-forming environment. In an equilibrium weakly alkaline fluid up to 200 ∘C, hydroxocomplexes are prevalent for all REEs with the ratio Ln(OH)03> Ln(OH)+2. The first chloro complex for light REE at 500–400 ∘C, and the second fluoro complex for medium and heavy REEs follow them. At 100 ∘C, the concentration of hydroxocomplexes sharply decreases, and fluorine and carbonate complexes come to the fore. In general, there is an increased stability of the first chlorocomplex in the high-temperature region, and with decreasing temperature, the role of REE fluorocomplexes increases. Two variants of acidity-alkalinity calculations presumably correspond to modeling of two types of fluids: greisenizing – weakly acidic and carbonatite-forming – weakly alkaline.

Publisher

Geophysical Center of the Russian Academy of Sciences

Reference30 articles.

1. Степанчикова С. А., Битейкина Р. П., Широносова Г. П. и др. Экспериментальное изучение поведения гидроксидных комплексов в близнейтральных и щелочных растворах редкоземельных элементов и иттрия при 25 ∘C // Геология и геофизика. — 2014. — Т. 55, № 8. — С. 1188—1193., Stepanchikova S. A., Biteikina R. P., Shironosova G. P., et al. An experimental study of hydroxo complex formation in basic and near-neutral solutions of rare-earth elements and yttrium at 25 ∘C // Russian Geology and Geophysics. — 2014. — Vol. 55, no. 8. — P. 1188–1193.

2. Широносова Г. П., Прокопьев И. Р. Термодинамическое моделирование распределения РЗЭ+Y по формам в охлаждающихся богатых сульфатной серой флюидах // Известия Томского политехнического университета. Инжиниринг георесурсов. — 2019. — Т. 330, № 11. — С. 7—18. — DOI: 10.18799/24131830/2019/11/2343., Shironosova G. P., Prokopyev I. R. Thermodynamic modeling of REE + Y speciation in cooling sulfate-rich fluids // Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering. — 2019. — Vol. 330, no. 11. — P. 7–18. — DOI: 10.18799/24131830/2019/11/2343.

3. Gysi A. P., Harlov D., Filho D. C., et al. Experimental determination of the high temperature heat capacity of a natural xenotime-(Y) solid solution and synthetic DyPO4 and ErPO4 endmembers // Thermochimica Acta. — 2016. — Vol. 627–629. — P. 61–67. — DOI: 10.1016/j.tca.2016.01.016., Gysi A. P., Harlov D., Filho D. C., et al. Experimental determination of the high temperature heat capacity of a natural xenotime-(Y) solid solution and synthetic DyPO4 and ErPO4 endmembers // Thermochimica Acta. — 2016. — Vol. 627–629. — P. 61–67. — DOI: 10.1016/j.tca.2016.01.016.

4. Gysi A. P., Williams-Jones A. E., Harlov D. The solubility of xenotime-(Y) and other HREE phosphates (DyPO4, ErPO4 and YbPO4) in aqueous solutions from 100 to 250 ∘C and psat // Chemical Geology. — 2015. — Vol. 401. — P. 83–95. — DOI: 10.1016/j.chemgeo.2015.02.023., Gysi A. P., Williams-Jones A. E., Harlov D. The solubility of xenotime-(Y) and other HREE phosphates (DyPO4, ErPO4 and YbPO4) in aqueous solutions from 100 to 250 ∘C and psat // Chemical Geology. — 2015. — Vol. 401. — P. 83–95. — DOI: 10.1016/j.chemgeo.2015.02.023.

5. Haas J. R., Shock E. L., Sassani D. C. Rare earth elements in hydrothermal systems: Estimates of standard partial molal thermodynamic properties of aqueous complexes of the rare earth elements at high pressures and temperatures // Geochimica et Cosmochimica Acta. — 1995. — Vol. 59, no. 21. — P. 4329–4350. — DOI: 10.1016/0016-7037(95)00314-P., Haas J. R., Shock E. L., Sassani D. C. Rare earth elements in hydrothermal systems: Estimates of standard partial molal thermodynamic properties of aqueous complexes of the rare earth elements at high pressures and temperatures // Geochimica et Cosmochimica Acta. — 1995. — Vol. 59, no. 21. — P. 4329–4350. — DOI: 10.1016/0016-7037(95)00314-P.

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