Separation factors for lithium isotope exchange on the amberlite IR-120 cation exchange resin

The effect of concentration on the elementary separation factor for various lithium compounds (LiNO3, LiCl, Li2SO4, CH3COOL1, and LiOH) has been investigated using the breakthrough technique on an exchange column. Depending on the concentration and the anion, the separation factors vary from 1.019 to 0.999, 7Li being enriched in the solution. In cases of the chloride and nitrate solutions distinct maxima at the concentration of 2 N (1.019 and 1.014 resp.) are observed. Minima appear at 3 resp. 4 N with factors of 1.007 and 0.999. The solutions of sulfate, acetate, and hydroxide show factors between 1.0021 and 1.0003 with a less pronounced concentration dependence. Addition of alcohol, glycol or dioxane to the lithium salt solutions acts in the sense of decreasing the separation parameters. A qualitative explanation is based on ion pair formation