H+/Li+ (cat)ion exchange at Mn oxide surface
Ooi et al. (2016) put in presence 1 liter of Li brine ([Li]0 = 0.23 M) with 5 masses (10, 20, 30, 40 and 50 g) of Mn oxide which surface was initially proton-saturated (cation exchange capacity = 4.8 meq/g). After equilibration, they measured the Li concentration in the supernatant brine (expressed in mol/L) and the quantity of metal that is fixed at the surface of the Mn oxide (expressed in mol/g of Mn oxide). This experiment has been simulated with a PHREEQC model including a H+/Li+ exchange equilibrium : \( \ce{Li+ + HX <=> LiX + H+} \), where X is the site at the Mn oxide surface where H+ and Li+ are exchanged. The following plot shows the compared experimental and modeling results.
