Preparation of Montmorillonite Particles and Adsorption Characteristics for La Ions

In order to solve the problem of difficult solid-liquid separation or low permeability of the adsorption column when powdered montmorillonite is used as an adsorbent, the preparation conditions, structural characterization of montmorillonite granules and their adsorption characteristics for La were studied. The research results show that by adding 5% sodium silicate binder of montmorillonite and 9% polyvinyl alcohol pore-forming agent, aging for 12 h and calcining in a muffle furnace at 550 ℃ for 2 h, the montmorillonite granules with a loss rate of 0.6% and La ion adsorption rate of 92% can be obtained. The crystal structure of montmorillonite particles still maintains a layered structure, and the cation exchange capacity and specific surface area are only reduced by 34 mmol/kg and 4.3 m²/g, respectively, compared with the original montmorillonite. The adsorption process of La³⁺ on the montmorillonite particles reached equilibrium after 1 h, and the maximum adsorption amount was 0.24 mmol/g. The pseudo-first-order kinetic model and Freundlich adsorption isotherm model can better fit the adsorption process of La³⁺ on montmorillonite granules.