-
摘要: 采用统计热力学方法,利用CHEQ程序对5.5~7.7 GPa的压力和1 000~2 900 K温度下碳加水体系中碳的溶解度进行了计算。重点研究了石墨和金刚石在水中溶解度差与压力的关系,得出如下结果:(1)在一定压力下,使石墨和金刚石在水中的溶解度之差X(C)为正值的温度有确定的下限和上限。(2)在高温高压下,对每一个压力,石墨和金刚石在水中的溶解度之差X(C)都有一个极大值。使X(C)为极大值的温度随着压力的升高而增大,同时,溶解度差的极大值本身也随压力的升高而增大。Abstract: By statistical thermodynamics methods and CHEQ code, the concentrations of carbon in the system of graphite-water were calculated at 5.5~7.7 GPa and 1 000~2 900 K. Relation between the concentration of carbon in water and the pressure was mainly studied. Results could be summarised as follows: (1) At a fixed pressure, there is a definite down-limit and a up-limit of temperature, between them the concentration difference of graphite and diamond in water X(C) is positive; (2) Under a definite pressure, there is a maximum of the concentration difference of graphite and diamond in water. Both of the maximum of X(C) and the temperature, which make X(C) maximum, increase with the increase of the pressure remarkably.
-
Key words:
- high pressure /
- C-H-O supercritical-fluid /
- synthesis of diamond
-
Melton C E, Giardini A A. The Composition And Significance of Gas Released from Natural Diamond from Africa and Brazil [J]. Am Mineral, 1974, 59: 775-782. Haggerty S E. Diamond Genesis in a Multiply-Constrained Model [J]. Nature, 1986, 320: 34-38. Navon O, Hutcheon I D, Rossman G R, et al. Mantle-Derived Fluids in Diamond Micro-Inclusions [J]. Nature, 1988, 335: 784-789. Schrauder M, Navon O. Solid Carbon Dioxide in a Natural Diamond [J]. Nature, 1993, 365: 42-44. Taylor W R. Stable Isotopes and Fluid Processes in Mineralization [M]. Australia: University of Western Australia Pub No. 23, 1990. 333. Yamaoka S, Akaishi M, Kanda H, et al. Crystal Growth of Diamond in the System of Carbon and Water under Very High Pressure and Temperature [J]. J Cryst Growth, 1992, 125: 375-377. Hong S M, Akaishi M, Yamaoka S. Nucleation of Diamond in the System of Carbon and Water under Very High Pressure and Temperature [J]. J Cryst Growth, 1999, 200: 326-328. Yamaoka S, Shaji Kumar M D, Akaishi M. Reaction between Carbon and Water under Diamond-Stable High Pressure and High Temperature Conditions [J]. Diamond and Related Materials, 2000, 9: 1480-1486. Liu F S, Hong D G, Zhou X F. Theoretical Research on the Hugoniot Curves of the Mixtures of Carbon and Water [J]. Chinese Journal of High Pressure Physics, 2001, 15 (3): 186-192. (in Chinese) 刘福生, 洪德贵, 周雪芬. 碳水混合物冲击压缩特性的理论研究 [J]. 高压物理学报, 2001, 15(3): 186-192. Liu F S , Hong S M, Jing F Q. Dissolvability of Carbon in HP-HT Water [J]. J Phys: Condens Matter, 2002, 14: 1-5. Xiao W S, Weng K N, L G C, et al. Experiment on Reaction of Polyethylene and Water under High Pressure and High Temperature [J]. Chinese Journal of High Pressure Physics, 2001, 15(3): 169-176. 肖万生, 翁克难, 律广才, 等. 聚乙烯与水反应的高温高压实验及热力学探讨 [J]. 高压物理学报, 2001, 15(3): 169-176. van Thiel M, Ree F H. High-Pressure Liquid-Liquid Phase Change in Carbon [J]. The American Physical Society, 1993, 48: 3591-3599. Wertheim M S. Exact Solution of the PERCUS-YEVICK Integral Equation for Hard Spheres [J]. Phys Rev Lett, 1963, 10: 321-323. Ree F. A Statistical Mechanical Theory of Chemically Reacting Multiphase Mixtures: Application to the Detonation Properties of PETN [J]. J Chem Phys, 1984, 81(30): 1251-1263. van Thiel M, Ree F H, Haselman L C. Accurate Determination of Pair Potentials For a CwHxNyOz System of Molecules: a Semiempirical Method [R]. UCRL-ID-120096, 1995. Yao L Z. Fundamentals of Crystal Growth [M]. Hefei: Chinese Science and Technology University Press, 1995. 264-265. (in Chinese) 姚连增. 晶体生长基础 [M]. 合肥: 中国科学技术大学出版社, 1995. 264-265.
点击查看大图
计量
- 文章访问数: 13956
- HTML全文浏览量: 711
- PDF下载量: 957