{"title":"水二氧化碳深层流体中 NaCl 和 CaCl2 的分离","authors":"M. V. Ivanov, S. A. Bushmin","doi":"10.1134/S0869591124020036","DOIUrl":null,"url":null,"abstract":"<p>The possibility of changing the ratio of the concentrations of NaCl and CaCl<sub>2</sub> salts in fluid phases formed as a result of heterogenization of the H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> fluid with a decrease in <i>P-T</i> parameters has been studied. A well-known experimental fact regarding the ternary systems H<sub>2</sub>O–CO<sub>2</sub>–NaCl and H<sub>2</sub>O–CO<sub>2</sub>–CaCl<sub>2</sub> is the greater tendency of the H<sub>2</sub>O–CO<sub>2</sub>–CaCl<sub>2</sub> system to separate into coexisting predominantly aqueous-salt and aqueous-carbon dioxide phases compared to the similar system H<sub>2</sub>O–CO<sub>2</sub>–NaCl. This experimental fact can be interpreted as a greater affinity of NaCl for CO<sub>2</sub> compared to CaCl<sub>2</sub>. Using a recently developed numerical thermodynamic model of the H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> quaternary fluid system, it was possible to identify geologically significant consequences of this difference in the interaction of NaCl and CaCl<sub>2</sub> with CO<sub>2</sub>. Multistage heterogenization of the H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> fluid with a significant decrease in <i>P-T</i> parameters ultimately leads to the formation of aqueous-carbon dioxide fluid phase f2, the salt component of which is significantly enriched in NaCl and depleted in CaCl<sub>2</sub> compared to the initial fluid. The fluid phase f1 formed at each stage of heterogenization has a predominantly water-salt composition with the ratio of the mole fractions of NaCl and CaCl<sub>2</sub> salts, differing little from that in the initial fluid. However, the total mole fraction of salt in the f1 phase, as a rule, significantly exceeds that in the original fluid. The density of phase f1 significantly exceeds the density of phase f2. During the process of multistage heterogenization of the fluid phase f1, there is no formation of a fluid with a significant enrichment of CaCl<sub>2</sub> compared to the initial ratio of the mole fractions of NaCl and CaCl<sub>2</sub>. At the same time, successive multiple separation of the f2 phase leads to the enrichment of its salt component in NaCl. Under favorable conditions, this process can lead to the formation of a fluid with almost pure NaCl salt. Changes in the salt composition of the fluid H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> are considered in application to the evolution of fluid composition along the regressive branch of the <i>P-T</i> trend of HP metamorphism and syngranulite metasomatism in the Lapland granulite belt.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"32 2","pages":"249 - 257"},"PeriodicalIF":1.0000,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Separation of Salts NaCl and CaCl2 in Aqueous-Carbon Dioxide Deep Fluids\",\"authors\":\"M. V. Ivanov, S. A. Bushmin\",\"doi\":\"10.1134/S0869591124020036\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The possibility of changing the ratio of the concentrations of NaCl and CaCl<sub>2</sub> salts in fluid phases formed as a result of heterogenization of the H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> fluid with a decrease in <i>P-T</i> parameters has been studied. A well-known experimental fact regarding the ternary systems H<sub>2</sub>O–CO<sub>2</sub>–NaCl and H<sub>2</sub>O–CO<sub>2</sub>–CaCl<sub>2</sub> is the greater tendency of the H<sub>2</sub>O–CO<sub>2</sub>–CaCl<sub>2</sub> system to separate into coexisting predominantly aqueous-salt and aqueous-carbon dioxide phases compared to the similar system H<sub>2</sub>O–CO<sub>2</sub>–NaCl. This experimental fact can be interpreted as a greater affinity of NaCl for CO<sub>2</sub> compared to CaCl<sub>2</sub>. Using a recently developed numerical thermodynamic model of the H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> quaternary fluid system, it was possible to identify geologically significant consequences of this difference in the interaction of NaCl and CaCl<sub>2</sub> with CO<sub>2</sub>. Multistage heterogenization of the H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> fluid with a significant decrease in <i>P-T</i> parameters ultimately leads to the formation of aqueous-carbon dioxide fluid phase f2, the salt component of which is significantly enriched in NaCl and depleted in CaCl<sub>2</sub> compared to the initial fluid. The fluid phase f1 formed at each stage of heterogenization has a predominantly water-salt composition with the ratio of the mole fractions of NaCl and CaCl<sub>2</sub> salts, differing little from that in the initial fluid. However, the total mole fraction of salt in the f1 phase, as a rule, significantly exceeds that in the original fluid. The density of phase f1 significantly exceeds the density of phase f2. During the process of multistage heterogenization of the fluid phase f1, there is no formation of a fluid with a significant enrichment of CaCl<sub>2</sub> compared to the initial ratio of the mole fractions of NaCl and CaCl<sub>2</sub>. At the same time, successive multiple separation of the f2 phase leads to the enrichment of its salt component in NaCl. Under favorable conditions, this process can lead to the formation of a fluid with almost pure NaCl salt. Changes in the salt composition of the fluid H<sub>2</sub>O–CO<sub>2</sub>–NaCl–CaCl<sub>2</sub> are considered in application to the evolution of fluid composition along the regressive branch of the <i>P-T</i> trend of HP metamorphism and syngranulite metasomatism in the Lapland granulite belt.</p>\",\"PeriodicalId\":20026,\"journal\":{\"name\":\"Petrology\",\"volume\":\"32 2\",\"pages\":\"249 - 257\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2024-04-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Petrology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://link.springer.com/article/10.1134/S0869591124020036\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Petrology","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1134/S0869591124020036","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Separation of Salts NaCl and CaCl2 in Aqueous-Carbon Dioxide Deep Fluids
The possibility of changing the ratio of the concentrations of NaCl and CaCl2 salts in fluid phases formed as a result of heterogenization of the H2O–CO2–NaCl–CaCl2 fluid with a decrease in P-T parameters has been studied. A well-known experimental fact regarding the ternary systems H2O–CO2–NaCl and H2O–CO2–CaCl2 is the greater tendency of the H2O–CO2–CaCl2 system to separate into coexisting predominantly aqueous-salt and aqueous-carbon dioxide phases compared to the similar system H2O–CO2–NaCl. This experimental fact can be interpreted as a greater affinity of NaCl for CO2 compared to CaCl2. Using a recently developed numerical thermodynamic model of the H2O–CO2–NaCl–CaCl2 quaternary fluid system, it was possible to identify geologically significant consequences of this difference in the interaction of NaCl and CaCl2 with CO2. Multistage heterogenization of the H2O–CO2–NaCl–CaCl2 fluid with a significant decrease in P-T parameters ultimately leads to the formation of aqueous-carbon dioxide fluid phase f2, the salt component of which is significantly enriched in NaCl and depleted in CaCl2 compared to the initial fluid. The fluid phase f1 formed at each stage of heterogenization has a predominantly water-salt composition with the ratio of the mole fractions of NaCl and CaCl2 salts, differing little from that in the initial fluid. However, the total mole fraction of salt in the f1 phase, as a rule, significantly exceeds that in the original fluid. The density of phase f1 significantly exceeds the density of phase f2. During the process of multistage heterogenization of the fluid phase f1, there is no formation of a fluid with a significant enrichment of CaCl2 compared to the initial ratio of the mole fractions of NaCl and CaCl2. At the same time, successive multiple separation of the f2 phase leads to the enrichment of its salt component in NaCl. Under favorable conditions, this process can lead to the formation of a fluid with almost pure NaCl salt. Changes in the salt composition of the fluid H2O–CO2–NaCl–CaCl2 are considered in application to the evolution of fluid composition along the regressive branch of the P-T trend of HP metamorphism and syngranulite metasomatism in the Lapland granulite belt.
期刊介绍:
Petrology is a journal of magmatic, metamorphic, and experimental petrology, mineralogy, and geochemistry. The journal offers comprehensive information on all multidisciplinary aspects of theoretical, experimental, and applied petrology. By giving special consideration to studies on the petrography of different regions of the former Soviet Union, Petrology provides readers with a unique opportunity to refine their understanding of the geology of the vast territory of the Eurasian continent. The journal welcomes manuscripts from all countries in the English or Russian language.