Distribution Coefficients—The distribution coeffi- cients for the partition of cesium and rubidium be- 103 eee ony ay an ne tween zirconium ferrocyanide and aqueous solutions of ammonium nitrate and nitric acid are shown in Figure 19. Using nitrie acid, the values of the distribution coefficient decrease from 3143 at zero acid concentration to 1.8 with 9 M acid. The rubidium is not at all strongly adsorbed, and the values of distribution coefficients decrease from 23.8 at zero acid concentration to 0.56 with 9 M acid. The differences between the distribution coefficients for cesium and rubidium for every acid concentration are large. 102 io! Similarly, there is a very sharp drop in the dis- Ceen a an rN meeps ear oe NH4NO3z SOLUTIONS HNO3 SOLUTIONS - Ka tribution coefficients for cesium from 3143 at zero NH,4NOz concentration to 123 with 2 M ammonium nitrate, and then a gradual decrease to 17 for 9 M. The distribution coefficients for rubidium decrease from 23.8 at zero ammonium nitrate concentration to ° io" = f= CESIUM The value of the distribution coefficient of 23.8 for the partition of rubidium between water and zirconium ferrocyanide is lower by a factor of almost one io! 0.95 at 8 M ammonium nitrate and show poor reproducibility. hundred for other heavy metal ferrocyanides investi- | L o + RUBIDIUM [odo i0 8 6 Fic. 17-—Distribution coefficients for partition of cesium gated. and rubidium between copper ferrocyanide and nitric acid or Separation of Cesium and Rubidium from Columns of Zirconium Ferrocyanide—The short ion exchange ammonium nitrate. 0.6 NeiRES oidRE ee ae. arta 0.51r— z ° Ee 0.4;r— < a ra z 6 MNH4NO3 Rb 1 PRE that ee, AEPBA YERe AN REayer RA mE re an org tad his age ves ure ite, 2 Zz 03 0. Oo ul > a 02 a uJ rd 8M NH4NO3 0.1 Cs 4 OQ oO | 2 ° | 4 l 6 | 8 oO Oo g Lobo 4 2 0 2 4 6 8 10 MOLARITY FM gee ae AT RN eT TT TTET Zirconium Ferrocyanide TT TTT 1o* TT TTTTF but there appears to be a little contamination with ceslum. POT TTT oe Mae See A RAeR EECNR te IRS 23 oO | Io | {2 | 14 | {§ VOLUME {milliliters} Fic. 18.—Separation of rubidium and cesium using copper ferrocyanide | t8