第34卷，第7期 2014年7月
光谱学与光谱分析 Spectroscopy and Spectral Analysis
Vol. 34,No. 7 -ppl747-1753
July，2014
Raman Spectroscopic Quantitative Study of NaCI-CaCl2-H2O System
atHighTemperatures andPressures LI Jing',MAO Shi-del",ZHENG Hai-fei?2.3
1. School of Earth Sciences and Resources , China University of Geosciences , Beijing 100083, China
2 . Key Laboratory of Orogenic Belts and Crustal Evolution , Ministry of Education , Bejing 100871, China 3. School of Earth and Space Science , Peking University , Beijing100871 , China
Abstract Raman spectra features of the ternary system NaCl-CaCl2-H2 O under high temperatures and high pressures were systematically studied in the present work by using hydrothermal diamond anvil cell (HDAC) and Raman shifts of quartz to determine pressures , and it has been obtained for the quantitative relationship between Raman shifts of the OH stretching band of water , mass fractions of solutes and pressures was ob -tained. The mass fractions of salts , where salinity of NaCl equal to that of CaClz , are 4. O mass% , 8. O mass% , and 12. O mass% , respectively , Experimental results indicate that the standardized Raman frequency shift differences of the O—H stretching vibration (voH ) rise with the increasing temperatures when the mass fractions of salts and pressures of the NaCl-CaCl2-H2 O system remain constant . xoH) increases with the increase in mass fractions of salts in the system when the temperatures and pressures are constant . Linear relationship between △xoH) and pressure with similar slopes can be found for the NaCl-CaCl-H: O system with different salinities . The quantitative relationship between voH) , temperature (T), pressure ( P), and mass fraction of solute (M) is P= 31.892△xoH) +10.131 T+ 222. 816M—3 183. 567, where the valid PTM range of the equation is 200 MPa P1 700 MPa , 273 K 7539 K and M12 mass/ . The equation can be used as a geobarometer in the studies of fluid inclusions of NaCl-CaCl -H2 O system with equal salini-ties . The method, as a direct geological detecting technique , has a potential application value .
Keywords Raman spectra : Diamond anvil cell ; NaCl-CaCl2 -H2 O ; Quantitative relationship : PVTx
中图分类号：0657.3
Introduction
文献标识码：A
DOI : 10. 3964 /i issn. 1000-0593 (2014 )07-1747-07
posits . Therefore , knowledge of thermodynamic properties of the NaCl-CaCl: -H: O system can better explain corresponding geological phenomena and patterns . However , the research-
Numerous fluid inclusion studies indicate that water-salt system is a much more important natural ore-forming fluid system , which often participates in a variety of geological ac -tivities . Ternary system NaCl-CaCl-H: O is one of common natural water-salt systems in many geological environments , e -g -, geothermal fields , metamorphic rocks , oceanic hydro-thermal system , oil reservoirs and gold-nonferrous metal de-
Received : 2013-06-17 ; aceepted : 2013-11-06
ers in the past only studied the various phase behaviors of this system at low temperatures . Mao) studied the Raman spec-tra features of the ternary system at low temperatures . Ding and Nil2J studied the frozen and melting behaviors of the ter-nary system by using the synthetie fluid inclusion technique . Samson and Walkeris] observed the phase behaviors of fluid inclusions of the ternary system at low temperatures by using Raman spectroscopy technique . However , the quantitative re.
Foundation item : The National Natural Science Foundation of China (41173072 ) and the Fundamental Research Funds for the Central U niversi -
ties (2652013032)
Biography : LI Jing , (1987—), female , masters degree
Corresponding author
e-mail : memorylee0808@ hotmail .com
e-mail ; maoshide@ 163.com