Abstract: STUDY ON ION EXCHANGE MECHANISM OF POTASSIUM TITANIUM HEXACYANOFERRATE FOR CS~＋IONXu Shiping ; Jiang Changyin; Song Chongli(Institute of Nuclear Energy and Technology, Tsing Hua Univrsity, P. O Box 1021,Beijing 102201)Abstract:The exchange mechanism of potassium titanium hexacyanoferrate for Cs ~ + in nitrate medium is studied. Ion exchange occurs between Cs~+ and K~+ in lower Cs~+ concentration solution and TiO2~+ takes part in exchange with the increase of Cs~+ concentration. The study of the effects of temperature, stirring intensity and particle size on exchange speed shows that exchange process is controlled by membrane diffusion and particle diffusion at lower stirring intensity and by particle diffusion at higher stirring intensity. The effects of main cations in simulated high level radioactive liquid waste(HLLW)on Cs~+ exchange are studied. The results demonstrate that this ex changer has excellent selectivity for Cs~+.Keywords: Potassium titanium hexacyanoferrate Cs~+ HLLW Ion exchange