The system NaCl-H2O: Relations of vapor-liquid near the critical temperature of water and of vapor-liquid-halite from 300° to 500°C
The system NaCl-H2O: Relations of vapor-liquid near the critical temperature of water and of vapor-liquid-halite from 300° to 500°C
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NaCl-H2O 系统：水临界温度附近的汽-液关系以及 300° 至 500°C 范围内汽-液-石盐的关系
DOI：
10.1016/0016-7037(86)90317-0
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发表时间：
1986
影响因子：
5
通讯作者：
K. Pitzer
中科院分区：
文献类型：
--
作者：
J. Bischoff;R. Rosenbauer;K. Pitzer
在跨越水的临界温度（Tc）的温度下，实验测定了NaCl-H2O系统的汽液关系（P-T-x），临界温度是系统中发生临界行为的最低温度。此外，还测定了300° ~ 500°C的气-液-盐P-T-x（气相）关系。结果表明，在373.0°C，即低于Tc时，等温汽液P-x边界的汽侧形状与以前设想的完全不同。蒸汽中的NaCl含量随压力以平稳的方式从三相组合的压力（135巴，0.0029%NaCl）增加到刚好低于纯水的蒸汽压的压力（0.012%NaCl，184巴）。在此压力以上，边界突然反转，并在218巴（纯水的蒸汽压）下以喙状形状渐近地投射到0%NaCl。在375.5°，稍高于Tc，渐近线消失，取而代之的是一个圆形的鼻子。在逐渐升高的温度下，鼻子消失，到380°C时，熟悉的对称钟形曲线占主导地位，临界点由钟的顶部定义。本文所测定的三相组合的P-T曲线与前人的结果一致。然而，在高于410°C的温度下，三相蒸气的NaCl含量远高于某些文献值。
Vapor-liquid relations (P-T-x) for the system NaCl-H2O were determined experimentally at temperatures spanning the critical temperature of water (Tc), the lowest temperature in the system at which critical behavior occurs. In addition, vapor-liquid-haliteP-T-x(vapor) relations were determined from 300° to 500°C. Results show that at 373.0°C, immediately belowTc, the vapor side of the isothermal vaporliquid P-x boundary has a shape quite different from that previously conceived. The NaCl content of the vapor increases with pressure in a smooth manner from the pressure of the three-phase assemblage (135 bars, 0.0029% NaCl), to a pressure just below that of the vapor pressure of pure water (0.012% NaCl at 184 bars). Above this pressure the boundary abruptly reverses and projects asymptotically to 0% NaCl in a beak-like shape at 218 bars, the vapor pressure of pure water. At 375.5°, slightly aboveTc, the asymptote disappears, and is replaced by a rounded nose. At progressively higher temperatures, the nose disappears and by 380°C the familiar symmetrical bell-shaped curve predominates with the critical point defined by the top of the bell. TheP-Tcurve of the three-phase assemblage determined in the present study is in agreement with previous workers. The NaCl content of the three-phase vapor, however, is much higher than some literature values at temperatures above 410°C.