2002 Fiscal Year Final Research Report Summary
Numerical analyses of geochemical processes with boiling and / or mixing fluids
| Project/Area Number |
13640481
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Petrology/Mineralogy/Science of ore deposit
|
|---|
| Research Institution | HIROSHIMA UNIVERSITY |
|---|
Principal Investigator |
HOSHINO Kenichi Hiroshima Univ. Graduate School of Science, Assistant, 大学院・理学研究科, 助手 (80190198)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
WATANABE Makoto Hiroshima Univ. Graduate School of Science, Professor, 大学院・理学研究科, 教授 (80033900)
|
|---|
| Project Period (FY) |
2001 – 2002
|
| Keywords | water-rock interaction / boiling / ore deposition / equation of state / MIX99 / dielectric constant |
|---|
| Research Abstract |
The main subject of this research project is to refine the water-rock interaction simulator MIX99 (Hoshino et al., 2000) by introducing an equation of state (EOS) of geological fluids and the geochemical date processing code SUPCRT92 (Johnson et al., 1992) in it. The all EOS's for the NaC1-CO^2-H_2O system at high temperatures and pressures proposed in the recent 20 years have been examined. It has been clarified that the EOS's are not sufficiently accurate for enthalpy calculation due to their inexact interaction parameters of NaC1-H_2O. Because of this reason, the simulated processes are restricted for 1) non-isenthalpic boiling of the NaC1-CO_2-H_2O fluids and 2) isenthalpic and semi-isenthalpic boiling of the CO_2-H_2O fluids. The analytical result of the process 2) is followed by a remarkable conclusion that boiling of the fluid could not be a direct trigger of mineral deposition. The result also showed an important roll of a varying dielectric constant of the fluid during boiling. However, unfortunately, the dielectric constant for the NaC1-H_2O fluids at high temperature has not been evaluated yet. Therefore, an accurate equation for the constant is critically important for a future study of geochemical processes.
|
