A molecular dynamics study of Li speciation in hydrothermal fluids and silicate melts

被引:14
作者
Wang, Tianhua [1 ]
Zhang, Xiaoyu [1 ]
Liu, Xiandong [1 ]
Lu, Xiancai [1 ]
Wang, Rucheng [1 ]
机构
[1] Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposits Res, Nanjing 210023, Jiangsu, Peoples R China
基金
中国国家自然科学基金;
关键词
Lithium; Speciation; Silicate melts; Hydrothermal fluids; Association constant; Molecular dynamics; AQUEOUS LITHIUM-CHLORIDE; ALKALI-METAL HALIDES; HIGH-PRESSURE; ISOTOPE FRACTIONATION; COMPUTER-SIMULATION; ALUMINOSILICATE GLASSES; THEORETICAL ESTIMATION; SOLUTION MECHANISMS; HIGH-TEMPERATURES; PAIR ASSOCIATION;
D O I
10.1016/j.chemgeo.2021.120528
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Magmatic-hydrothermal ore-forming processes play an important role in the transport, enrichment and mineralization of Li. In this study, first principles molecular dynamics (FPMD) and classical molecular dynamics (CMD) techniques were employed to investigate the speciation of Li in silicate melts and hydrothermal fluids. FPMD results show that Li does not form stable ion pair with F or Cl in silicate melts, but forms four-fold Li-O coordination. Association constants of Li-F/Cl ion pairs in hydrothermal fluids under a wide range of T-P conditions (i.e., temperatures up to 1273 K and fluid densities ranging from 0.1 g/cm(3) to 1.0 g/cm(3)) derived with constrained CMD show increasing stability with temperature increasing or fluid density decreasing. Together with previous studies on Na/K-F/Cl ion pairs, an association constant database is provided for alkali halides ion pairs. It is found that Li-F ion pair is dominant in geological vapors.
引用
收藏
页数:11
相关论文
共 125 条
[1]   Fluorine speciation as a function of composition in peralkaline and peraluminous Na2O-CaO-Al2O3-SiO2 glasses: A multinuclear NMR study [J].
Baasner, A. ;
Schmidt, B. C. ;
Dupree, R. ;
Webb, S. L. .
GEOCHIMICA ET COSMOCHIMICA ACTA, 2014, 132 :151-169
[2]   The distribution of Na, K, Rb, Sr, Al, Ge, Cu, W, Mo, La, and Ce between granitic melts and coexisting aqueous fluids [J].
Bai, TB ;
van Groos, AFK .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1999, 63 (7-8) :1117-1131
[3]   Structure and dynamics of lithium silicate melts: molecular dynamics simulations [J].
Banhatti, RD ;
Heuer, A .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2001, 3 (23) :5104-5108
[4]   The effect of lithium on the viscosity of pegmatite forming liquids [J].
Bartels, Alexander ;
Behrens, Harald ;
Holtz, Francois ;
Schmidt, Burkhard C. .
CHEMICAL GEOLOGY, 2015, 410 :1-11
[5]   Lithium enrichment in intracontinental rhyolite magmas leads to Li deposits in caldera basins [J].
Benson, Thomas R. ;
Coble, Matthew A. ;
Rytuba, James J. ;
Mahood, Gail A. .
NATURE COMMUNICATIONS, 2017, 8
[6]   THE MISSING TERM IN EFFECTIVE PAIR POTENTIALS [J].
BERENDSEN, HJC ;
GRIGERA, JR ;
STRAATSMA, TP .
JOURNAL OF PHYSICAL CHEMISTRY, 1987, 91 (24) :6269-6271
[7]   Defects and oxygen diffusion in metasilicate melts: Molecular dynamics simulation [J].
Berezhnoi, GV ;
Boiko, GG .
GLASS PHYSICS AND CHEMISTRY, 2005, 31 (02) :145-154
[8]   From Mine to Mind and Mobiles: Society's Increasing Dependence on Lithium [J].
Bibienne, Thomas ;
Magnan, Jean-Francois ;
Rupp, Alexander ;
Laroche, Nicolas .
ELEMENTS, 2020, 16 (04) :265-270
[9]   Classification and Characteristics of Natural Lithium Resources [J].
Bowell, Robert J. ;
Lagos, Laura ;
de los Hoyos, Camilo R. ;
Declercq, Julien .
ELEMENTS, 2020, 16 (04) :259-264
[10]   A review of the coordination chemistry of hydrothermal systems, or do coordination changes make ore deposits? [J].
Brugger, Joel ;
Liu, Weihua ;
Etschmann, Barbara ;
Mei, Yuan ;
Sherman, David M. ;
Testemale, Denis .
CHEMICAL GEOLOGY, 2016, 447 :219-253