Liquid–Vapor Equilibria in the SiCl4–A (A = SiCl4–nFn (n = 1–4) Impurity) Systems

The vapor–liquid separation factors of SiCl4–A (A = SiCl4–nFn (n = 1–4) silicon fluorochloride impurities in silicon tetrachloride have been determined experimentally at 298 K by statically balancing phases. The values obtained for the SiCl4–SiCl3F, SiCl4–SiCl2F2, SiCl4–SiClF3, and SiCl4–SiF4 systems are 4.9 ± 0.8, 8.2 ± 1.2, 29.8 ± 6.1, and 42.0 ± 7.5, respectively. In the SiCl4–SiCl3F system, the vapor–liquid separation factor has also been determined by the Rayleigh distillation method: α = 5.0. The experimental data agree with the vapor–liquid separation factors estimated in conformal solution theory using parameters of the Lennard- Jones potential.