【摘要】 于300、400℃和500bar流动条件下使含铁的石灰岩、白云岩和菱铁矿石与不同酸度的Na-F溶液相互作用,系统地研究了实验产物的蚀变矿物学和溶液化学变化。结合实验结果讨论了白云鄂博铁矿床形或中的热液交代作用。更多还原

【Abstract】 In order to investigate the interaction between rocks and F-bearing hydrothermal solutions, Na-F solutions with different pH values were used to react with limestone, dolomite and siderite under a flowing condition at 300 and 400℃ and 500 bars. The chemical and mineralogical changes of the rocks were studied by chemical analysis, microscopy, XDR and SEM/EDAX. In the experiment at 300℃ the main altered minerals were iron oxides, iron-silicate and fluorite, while at 400℃ the mineral assemblage fluorite-wollastonite-aegirine was observed in the run on limestone, magnetite-fluorite-wollastonite in the run on dolomite, and magnetite-fayalite-fluorite in the run on siderite.Changes in solution chemistry were also studied. The content of F in the solutions decreased rapidly from the very beginning of the experiment as a result of the crystallization of fluorite, and variations in Na and F contents seem to have a similar tendency on the whole. SomeK, SiO₂ and CO₂ were always present in the reacting solutions, but almost no iron was observed even though the starting solution contained a certain amount of iron. This shows that carbonate rocks are an effective precipitant for iron in hydrothermal solutions.更多还原