Thermodynamic properties of copper chloride complexes and copper transport in magmatic-hydrothermal solutions
Thermodynamic properties of copper chloride complexes and copper transport in magmatic-hydrothermal solutions
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DOI：
10.1016/j.chemgeo.2005.04.009
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发表时间：
2005-09-05
期刊：
影响因子：
3.9
通讯作者：
McPhail, DC
中科院分区：
文献类型：
--
作者：
Liu, WH;McPhail, DC
铜在热液沃茨和盐水中的行为在岩浆热液系统典型的压力-温度-盐度条件下知之甚少，严重限制了我们对有多少铜可以在这种环境中运输和沉积的理解。我们需要知道相关铜络合物的身份，并具有可靠的热力学性质，以便了解和预测含铜矿物的溶解度，铜在液体和蒸汽之间的分配，以及哪些物理化学因素和过程控制岩浆热液系统中的铜沉积。在盐水条件下，氯化铜络合物可能是最重要的铜的水溶液物种，最近的实验研究表明，它们的衍生性质在高达约300摄氏度，蒸汽饱和压力和高达约9米的总氯化物的良好协议。在本文中，我们提出了新的状态方程参数和偏摩尔性质的水溶液铜（I）氯化物络合物（CUCl（aq），CUCl 2-，CUC 32-和CuCl 43-）回归从实验得出的log K值之间的25和350度C和蒸汽饱和压力。结果被用来计算形成常数为广泛的温度和压力范围（0-1000摄氏度和1-5000巴）。通过计算黄铜矿溶解度并将其与Seyfried和Ding（2003）[Seyfried，W.E.，丁，K.，1993.氧化还原对高温高压下含氯含水流体中铜和铁的相对溶解度的影响：应用于海底热液系统的实验研究。Geochimca et Cosmochimca Acta 57，1905-1917]; 400 ℃，500巴，0.4-2 μ m氯化物和Hentley等人（1992）[Hemley，J. J.，Cygan，G.L.，Fein，J.B.，罗宾逊，G.R.，小的，D ' Angelo，W. M.，1992.从岩石缓冲体系研究看热液成矿作用。1、铁-铜-锌-铅硫化物溶解度关系。Econ.Geol.87，1-22]; 300-500摄氏度，500-2000巴，1 M氯化物。有很好的协议，这两个实验数据集，这表明我们的外推的热力学性质是可靠的，至少在这些范围内的压力，温度和氯化物浓度。
The behaviour of copper in hydrothermal waters and brines is poorly known at the pressure-ternperature-salinity conditions typical of magmatic-hydrothermal systems, severely limiting our understanding of how much copper can be transported and deposited in such environments. We need to know the identity of relevant copper complexes and have reliable thermodynamic properties for them in order to understand and predict the solubilities of copper-bearing minerals, the partitioning of copper between liquid and vapour and which physico-chemical factors and processes control copper deposition in magmatic-hydrothermal systems. Under saline conditions, copper chloride complexes are likely to be the most important aqueous species of copper and recent experimental studies have shown good agreement for their derived properties up to approximately 300 degrees C, vapour-saturated pressure and up to approximately 9 m total chloride. There is still a need, however, to have reliable properties h for higher temperature and pressure conditions.In this paper we present new equation-of-state parameters and partial molal properties for aqueous Cu(I) chloride complexes (CUCl(aq), CUCl2-, CUC32- and CuCl43-) regressed from experimentally derived log K values derived between 25 and 350 degrees C and vapour-saturated pressure. The results are used to calculate formation constants for a wide range of temperature and pressure (0-1000 degrees C and 1-5000 bar). The extrapolation of the properties is tested by calculating chalcopyrite solubilities and comparing them with measured values from Seyfried and Ding (2003) [Seyfried, W.E., Ding, K., 1993. The effect of redox on the relative solubilities of copper and iron in Cl-bearing aqueous fluids at elevated temperatures and pressures: an experimental study with application to subseafloor hydrothermal systems. Geochimca et Cosmochimca Acta 57, 1905-1917]; 400 degrees C, 500 bars, 0.4-2 m chloride and Hentley et al. (1992) [Hemley, J.J., Cygan, G.L., Fein, J.B., Robinson, G.R., Jr., D ' Angelo, W.M., 1992. Hydrothermal ore-forming processes in the light of studies in rock-buffered systems. 1, Iron-copper-zinc-lead sulfide solubility relations. Econ. Geol. 87, 1-22]; 300-500 degrees C, 500-2000 bars, I m chloride. There is good agreement with these two experimental datasets, which indicates that our extrapolated thermodynamic properties are reliable at least over these ranges of pressure, temperature and chloride concentration.