DOWEX Resins for Separation of Group IVB from Liquid Media

Group IVB Titanium - Ti Zirconium - Zr Hafnium - Hf The Group IVB Elements of titanium, zirconium, and hafnium readily lose their four outer shell electrons to form +4 ions in solution. The group IVB elements are found as oxides, halides, sulfates, and mixed complexes. Due to their nearly identical atomic radii, Zr and Hf are virtually identical from a separation standpoint.

Applications

Titanium, zirconium and hafnium are present as cations in acid, so a strong acid cation resin like DOWEX™ G-26 (H) resin is the separation media of choice. In hydrochloric acid, Ti, Zr, and Hf have a high affinity for a strong acid cation resin under dilute acid conditions that diminish at about 4 to 8 M HCl then increase as acid concentrations increase. In perchloric acid, a strong acid cation resin has an even higher affinity for these cations. In HF and HCl, these elements also form anions that can be captured on a strong base anion exchange resin like DOWEX 21K XLT resin (1).

Often these metals are separated from other closely associated metals so resins with the maximum number of theoretical plates are needed. Strong acid cation fine mesh resins like DOWEX 50WX8 100-200 or DOWEX 50WX4 100-200 resins are proposed for this separation.

DOWEX Ion Exchange Resins

Product	Description	Type	Matrix	Total Exchange Capacity* eq/l (kgr/ft3)	Available Forms
DOWEX G-26 (H)	Uniform particle size strong acid cation exchange resin for specialty demineralization and catalyst applications.	Strong Acid Cation	Styrene-DVB, Gel	2.0	H+
DOWEX 21K XLT	Uniform particle size, high capacity, strong base anion exchange resin for mineral processing applications.	Type I Strong Base Anion	Styrene-DVB, Gel	1.4	Cl-
DOWEX 50WX4	Fine mesh resin for fine chemical and pharmaceutical column separations.	Fine Mesh	Styrene-DVB, Gel	1.1 meq/ml	H+
DOWEX 50WX8	Fine mesh resin for fine chemical and pharmaceutical column separation.	Fine Mesh	Styrene-DVB, Gel	1.7 meq/ml	H+

References 1. "Resin Selectivity in Dilute to concentrated Aqueous Solutions" by R.M. Diamond and D.C. Whitney, Chapter 8 of Ion Exchange – A Series of Advances Edited by J.A. Marinsky, Published by Marcel Dekker, Inc., New York (1966).