TY - JOUR

T1 - Thermodynamic modeling of REE+Y speciation in cooling sulfatebrich fluids

AU - Shironosova, Galina P.

AU - Prokopyev, Ilya R.

N1 - 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

PY - 2019

Y1 - 2019

N2 - The relevance of the work is caused by the fact that the study of speciation of lanthanide + yttrium (REE+Y) in chloride-sulfate-carbonate fluids in various weakly alkaline and weakly acidic conditions allows one to assess the effect of parameters of the ore-forming system on transportation and fractionation of rare-earth elements in oreogenesis within the carbonatite ore-magmatic systems. The main aim of the study is to estimate the contribution of the fluorine-, chloro-, carbarnate-bicarbonate, sulfate and phosphate complexes of REE+Y to transport and ore deposition by hydrothermal fluids in weakly alkaline and weakly acidic conditions at 500-100 °C and a pressure of 2000-125 bar. The methods: computational modeling of the effect of hydrothermal fluids on monazite and calcite using the HCh package (developed by Yu.V. Shvarov). To establish the equilibrium state in the program's algorithm, the method of determining the minimum Gibbs free energy of the system (the GIBBS program) in combination with the thermodynamic base UNITHERM, supplemented by experimental results for REE complexes and minerals, was used. The results. The paper introduces the distribution of REE+Y by forms in cooling chloride-sulfate-carbonate highly concentrated weakly acidic and weakly alkaline fluids. It was shown that under weakly alkaline conditions, the leading ones are the neutral and second hydrocomplexes up to 200 °C. As the temperature decreases to 100 °C, REE+Y are found in the form of the carbonate and second fluorocomplex (Ln, Y) F+ 2. Under weakly acidic conditions, sulfate complexes of lanthanides prevail sharply in the entire studied range of fluid parameters. With an increase in the lanthanide number (especially for heavy REEs), the role of fluoride complexes grows with a decrease in contribution of sulfate complexes.

AB - The relevance of the work is caused by the fact that the study of speciation of lanthanide + yttrium (REE+Y) in chloride-sulfate-carbonate fluids in various weakly alkaline and weakly acidic conditions allows one to assess the effect of parameters of the ore-forming system on transportation and fractionation of rare-earth elements in oreogenesis within the carbonatite ore-magmatic systems. The main aim of the study is to estimate the contribution of the fluorine-, chloro-, carbarnate-bicarbonate, sulfate and phosphate complexes of REE+Y to transport and ore deposition by hydrothermal fluids in weakly alkaline and weakly acidic conditions at 500-100 °C and a pressure of 2000-125 bar. The methods: computational modeling of the effect of hydrothermal fluids on monazite and calcite using the HCh package (developed by Yu.V. Shvarov). To establish the equilibrium state in the program's algorithm, the method of determining the minimum Gibbs free energy of the system (the GIBBS program) in combination with the thermodynamic base UNITHERM, supplemented by experimental results for REE complexes and minerals, was used. The results. The paper introduces the distribution of REE+Y by forms in cooling chloride-sulfate-carbonate highly concentrated weakly acidic and weakly alkaline fluids. It was shown that under weakly alkaline conditions, the leading ones are the neutral and second hydrocomplexes up to 200 °C. As the temperature decreases to 100 °C, REE+Y are found in the form of the carbonate and second fluorocomplex (Ln, Y) F+ 2. Under weakly acidic conditions, sulfate complexes of lanthanides prevail sharply in the entire studied range of fluid parameters. With an increase in the lanthanide number (especially for heavy REEs), the role of fluoride complexes grows with a decrease in contribution of sulfate complexes.

KW - Chloro-

KW - Fluoro-

KW - Hydroxy-

KW - Phosphate complexes

KW - REE+Y

KW - Speciation in the fluid

KW - Sulfate

KW - Sulfate-rich fluid

KW - Thermodynamic modeling

KW - sulfate

KW - FRACTIONATION

KW - thermodynamic modeling

KW - DEPOSITION

KW - COMPLEXES

KW - chloro-

KW - TRANSPORT

KW - fluoro-

KW - sulfate-rich fluid

KW - speciation in the fluid

KW - CARBONATITES

KW - hydroxy-

KW - STRANGE LAKE

KW - ZR

KW - RARE-EARTH-ELEMENTS

KW - SYSTEMS

KW - HYDROTHERMAL PROCESSES

KW - phosphate complexes

UR - http://www.scopus.com/inward/record.url?scp=85076043523&partnerID=8YFLogxK

U2 - 10.18799/24131830/2019/11/2343

DO - 10.18799/24131830/2019/11/2343

M3 - Article

AN - SCOPUS:85076043523

VL - 330

SP - 7

EP - 18

JO - Известия Томского политехнического университета. Инжиниринг георесурсов

JF - Известия Томского политехнического университета. Инжиниринг георесурсов

SN - 2500-1019

IS - 11

ER -