运用分子相互作用体积模型并结合Si、Al二元系的无限稀活度系数γ∞Si、γ∞Al,利用牛顿迭代法计算出对势能相互作用参数BSi,Al和BAl,Si,然后再利用BSi,Al和BAl,Si计算Al-Si二元系中Si和Al的活度系数γSi、γAl和活度aSi、aAl,进一步利用γSi、γAl计算出Al的分离系数βAl和蒸馏过程中Al的挥发速率,同时根据γSi、γAl绘制出Al-Si合金蒸馏过程中的气液相平衡图。研究结果表明:活度计算值与实验值吻合较好,由βAl〉〉1可预测,通过真空蒸馏能很好地实现Si和Al的分离。此研究为真空蒸馏分离铝硅合金提供了可靠的理论依据及预测模型,对于研究铝硅合金中铝的分离限度具有重要参考作用。
The feasibility of separation of aluminum-silicon alloy by vacuum distillation was analytically calculated on the basis ofmolecular interaction volume model( MIVM). First, the pair interaction potential terms, B si, Al. and B Al, si, in Gibbs free energy equation, formulated with MIVM model, were derived by manipulating the measured infinite-dilute-ac- tivity coefficients, γSi、γAl, of Al-Si binary systemin using Newton Raphson methodology. Next, the activities and activity coefficientsof Si and Al were estimated in terms of BSi,Al and BAI,Si. And finally, the Al separation coefficient from Al-Si alloy and Al evaporation rate in vacuum distillation were calculated. Besides, the vapor-liquid equilibrium diagram of Al- Sialloy was plotted. The predicted activities of Al and Si werefound to agree well with the measured results. The calculated separation coefficient of Al,βAl〉〉1, indicates that vacuum distillation is capable of separating Al and Si in Al-Si alloy. We suggest that the calculated results be of much technological interest.