Solid−Liquid and Liquid−Vapor Equilibria in the Zr(Hf)Cl4−KAlCl4 Systems: A Basis for the Extractive Distillation Separation of Zirconium and Hafnium Tetrachlorides

Autor: Egor A. Egorov, Vladimir D. Fedorov, Oksana A. Arzhatkina, Elena L. Chuvilina, Lev A. Niselson
Rok vydání: 2009
Předmět:
Zdroj: Journal of Chemical & Engineering Data. 54:726-729
ISSN: 1520-5134
0021-9568
DOI: 10.1021/je800299y
Popis: The relative volatility αHfCl4/ZrCl4 in molten potassium chloroaluminate, KAlCl4, has been determined using equilibrium Rayleigh vaporization from mixtures containing a 36 % mass fraction of ZrCl4 + 1.4 % HfCl4. At these component concentrations and at a temperature near 450 °C, the ZrCl4 + HfCl4 vapor pressure over the melt is close to atmospheric pressure. According to preliminary results, αHfCl4/ZrCl4 ≈ 1.29 ± 0.04. The ZrCl4−KAlCl4 and HfCl4−KAlCl4 systems have been studied by visual thermal analysis. The results confirm that they are simple binary eutectic systems. According to our data, the eutectic temperature in the ZrCl4−KAlCl4 system is 519 K, and the eutectic is located at a ZrCl4 mole fraction of 0.08. The HfCl4−KAlCl4 system has a eutectic at an HfCl4 mole fraction of 0.171 with a melting point of 507.5 K.
Databáze: OpenAIRE