铀熔体中Fe蒸气分压的测量及其活度计算

Dissolution Equilibrium of Iron Vapour and Activities of Iron in Liquid Uranium-Iron Solutions

摘要:

采用载流气体携带法测量了1500~1600 ℃范围U-Fe熔体上方Fe的蒸气分压，计算获得Fe在U熔体中的活度、活度系数及标准溶解自由能。结果显示，相对Raoult定律Fe为负偏差元素，1500和1600 ℃无限稀的铀熔体中Fe的活度系数g 分别为0.344和0.485，其在铀熔体中的标准溶解自由能与温度关系符合DG0＝–448 682+125.4T。

关键词:U-Fe熔体;Fe分压;活度;活度系数;标准溶解自由能DG0

Abstract:

A carrier method was used to measure the dissolution equilibrium of iron vapour over liquid U-Fe alloys from 1500 to 1600 °C, and then the activities as well as activity coefficients of iron in liquid U-Fe alloys were calculated from the results for iron. It is found that iron shows strong negative deviation from Raoult’s law, and the relationship between the standard free energy of dissolution reaction Fe(g)=[Fe]Y and temperature is DG0=–448682+125.4T. At 1500 and 1600 °C, the activity coefficients g of iron at infinite dilution are 0.344 and 0.485, respectively.

Key words:U-Fe melt; partial vapour pressure of iron; activities; activity coefficients; standard free energy of reaction DG0