NaCl-MgCl_2-H_2O体系低温拉曼光谱研究  

Cryogenic Raman Spectroscopic Studies in the System of NaCl-MgCl_2-H_2O

作　　者：杨丹[1,2] 徐文艺[2] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质科学院矿产资源研究所,北京100037

出　　处：《光谱学与光谱分析》2010年第3期697-701,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(40303008);国家科技支撑计划课题项目(2006BAB01B06);科技部(973计划)项目(2002CB412605)资助

摘　　要：通过在低温下进行大量的最优生成条件的实验探索,得到了NaCl-H2O体系和MgCl2-H2O体系水合物生成的最优实验条件——迅速降温至-180℃然后缓慢升温至观察到水合物生成过程结束(即视野突然变暗),最后快速降温至-180℃。对NaCl-MgCl2-H2O体系进行了定性和半定量尝试,并得到结论:3 537cm-1可以指示NaCl的存在,3 514 cm-1可以指示MgCl2的存在;3 537和3 514 cm-1峰的相对高低可以大致判断出NaCl和MgCl2的相对多少。这一发现为天然包裹体液相成分拉曼光谱原位定性、定量分析奠定了良好的基础。对于历史上亚稳低共熔混合物形成过程的模式的争议,实验结果初步赞同了Samson等的观点,即冰在最初的冷却中形成,在冰之间的空隙中剩余过饱和的盐溶液,再次升温时,盐的水合物从这个液体中结晶出来。In the present paper, the best experimental conditions for producing hydrates in the NaCl-H2O and MgCl2-H2O systems were found through the cryogenic Raman spectroscopy. This experimental condition is rapidly cooling to - 180℃ and slowly warming to observe hydrate formation process （that is manifested as a darkening of the vision in the microscope）, and finally, rapidly cooling down to - 180℃. Moreover, a qualitative or semiquantitative analytical method for NaCl-MgCl2-H2O system was established. This method is that 3 537 cm^-1 may instruct the existence of NaCI hydrates, 3 514 cm a may instruct the existence of MgCl2 hydrates, and comparison of the intensity of 3 537 and 3 514 cm^-1 peaks can be used to estimate the ratio of NaCl and MgCl2 in the system. All these are the foundations for quantifying the components of natural fluid inclusions. The author supports Samson＇s idea through observing the phenomenon of experiments in the controversy of the meta-stable eutectics formation model, that is ice forms on initial cooling, leaving a residual, interstitial, hypersaline liquid. On warming, the salt hydrates crystallize from this liquid.

关 键 词：流体包裹体成分 二元或多元水盐体系 低温 拉曼光谱 

分 类 号：O657.3[理学—分析化学]