Experiments of Mechanisms of Gold Precipitated by Fluid-Mixing Function
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摘要: 为了研究流体混合作用导致金沉淀的两种主要机理, 通过简化实验体系、分离影响因素, 分别设计了降温、盐度变化导致金沉淀的模拟实验.研究表明:(1)随温度降低溶液的金溶解度也随之降低, 二者之间呈现一种复杂的函数关系; 在300 ℃左右的温度段, 是金沉淀的一个很有地质意义的温度区间;(2)含金流体盐度的降低, 引起流体中金的配位基浓度降低, 导致金沉淀;(3)岩石中发生碱交代有利于金定位富集Abstract: Simulate experiments of gold precipitated by lowering temperature and changing salt-content are designed by simplifying experimental system and separating influential factors in order to study two main mechanisms of gold precipitated by fluid-mixing function. The study shows first of all that the Au content in solution is lower with the falling temperature of solution, with a kind of complex functional relationship between them, and 300 ℃ as the most significant temperature in geology for gold mineralization.Second, lowering the salt content of the Au-fluid reduces the content of complex foundation, and lead to the gold precipitating. Third, the alkalic metasomatism in the rock is beneficial to gold mineralization.
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图 1 0.1 ml/L HCl溶液中金溶解度拟合曲线[1]
Fig. 1. Curve of gold solubility in 0.1 ml/L HCl solution
图 2 NaCl-H2O体系中金溶解度拟合曲线[1]
Fig. 2. Curve of gold solubility in NaCl-H2O system
表 1 不同温度下溶液中金的沉淀实验
Table 1. Experiments of gold precipitating in solution under different temperatures
表 2 不同NaCl质量浓度溶液中金的沉淀实验
Table 2. Experiments of gold precipitation in solution under different NaCl mass concentrations
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