A method is provided to optimize separation of zirconium from hafnium by extraction of a feed mix including (Zr+Hf)OCl 2 with a thiocyanate-containing organic phase The method includes maintaining the TA/MO 2 ratio in a range from greater than about 255 to about 35

Method for separating hafnium from zirconium

A scrub solution is made up for use in starting up a hafnium liquid-liquid extraction system. An aqueous zirconium oxychloride-containing solution is contacted with methyl isobutyl ketone containing less than 1 Molar thiocyanic acid. The aqueous solution is maintained at a chloride concentration of 1.6 to 3.5 Normal (as HCl) by addition of concentrated hydrochloric acid. Ammonium thiocyanate is added to the acidified aqueous stream to produce thiocyanic acid. The high acidity of the aqueous solution drives the thiocyanic acid into the methyl isobutyl ketone without the chloride anions having a depressing affect on the transfer. The thiocyanic acid-containing MIBK may then be used as a scrubbing solvent to start up the hafnium extraction system.

Process for producing a hafnium extraction scrub solvent

On complete une solution d'epuration destinee a etre utilisee dans le demarrage d'un systeme d'extraction liquide-liquide de hafnium. On met une solution aqueuse contenant de l'oxychlorure de zirconium en contact avec de la methyl-isobutyl-cetone contenant moins d'1 mole par litre d'acide thiocyanique. On maintient la concentration d'ions chlorure dans la solution aqueuse entre 1,6 et 3,5 N (en HCl), par addition d'acide chlorhydrique concentre. On ajoute du thiocyanate d'ammonium au courant aqueux acidifie, pour produire de l'acide thiocyanique. La forte acidite de la solution aqueuse fait migrer l'acide thiocyanique dans la methyl-isobutyl-cetone, et les anions chlorures ne genent aucunement cette migration. La methylisobutyl-cetone contenant de l'acide thiocyanique peut ensuite etre utilisee comme solvant d'epuration pour le demarrage d'un systeme d'extraction du hafnium.

Abodishish Hani Ahmed

Papers

Process for producing a hafnium extraction scrub solvent

Procede de production d'un solvant d'epuration pour l'extraction de hafnium.