SEPARATION OF ZIRCONIUM FROM HAFNIUM BY ION EXCHANGE

The current work consists in the separation of zirconium and hafnium by the ion exchange method in order to obtain a zirconium concentrate of high purity. The zirconium and hafnium liquors were produced from the leaching of the Zr (OH)(4) and Hf (OH)(4) with nitric acid for 24 hours. From these two liquors it was prepared one solution containing 7,5x10(-2) mol L-1 of Zr and 5,8x10(-3) mol L-1 of Hf with acidity of 1 M. Ion exchange experiments were carried out in batch with the resins Dowex 50WX4, Dowex 50WX8 100, Dowex 50WX8 50, Amberlite IR-120 and Marathon C at constant temperature 28 degrees C. Other variables such as, acidity and agitation were kept constant. The data were adjusted to Langmuir equation in order to calculate the maximum loading capacity (q(max)), the distribution coefficient (Kd) for Zr and Hf and the separation factor (a(Hf)(Zr)). The results of maximum loading capacity (q(max)) for Zr and Hf, in mmol g(-1), showed that the most suitable resins for columns experiments are: Dowex 50WX4 50, Dowex 50WX8 50 and Amberlite. However, separations factors showed that the resins are not selective.