Verfahren zur Trennung von Stoffgemischen, insbesondere von Zirkon-Hafnium aus rhodanidhaltigen Phasen durch Fluessig-Fluessig-Verteilung

摘要

The separation of mixtures of zirconium and hafnium or niobium and tantalum is effected by feeding the mixture directly into one or both phases in a liquid-liquid partitioning system, both phases of which contain thiocyanic acid. As shown in the Figure, the solid mixture is fed from container D via worm screw C into vessel 8 where it is stirred with stirrer E into the two immiscible liquids which flow in counter-current from the feeds at opposite ends of the apparatus A and B. Each vessel consists of a mixing and separating portion. Reference is made to separating zirconium/hafnium tetrachloride or oxychlorides by means of a water/thiocyanic acid methyl isobutyl ketone, two phase system, and also to separating niobium/tantalum pentachlorides by means of a water/thiocyanic acid/cyclohexanone system. Comparative Examples 2 and 3 describe solutions of the mixtures being added to the partitioning system, e.g. zirconium/hafnium tetrachlorides in aqueous thiocyanic acid and zirconium/hafnium oxychlorides in water. Example (4) describes a zirconium/hafnium thiocyanate solution being formed by charging a cation exchanger with an oxychloride solution of the metals and then eluting with ammonium thiocyanate, the solution thus formed then being added as before to the partitioning system.