Mass transfer rates in ion exchange

The rates of both the liquid‐phase mass transfer and the internal‐diffusion steps in ion exchange were studied by means of shallow‐bed experiments. The mass transfer coeffcients obtained fitted the general correlations for other packed‐bed operations when the Schmidt group was evaluated with experimentally determined ionic counterdiffusivities. An incremental calculation of the diffusion rates within the particles yielded a value of the counterdiffusivity in the resin phase. A general design procedure based on these findings is proposed.