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 montmoril-lonite 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 fur-nace at 550 ℃ for 2 h,the montmorillonite granules with a loss rate of 0.6％and La ion adsorption rate of 92％can be ob-tained.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 montmoril-lonite.The adsorption process of La3+ on the montmorillonite particles reached equilibrium after 1 h,and the maximum adsorp-tion 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.
montmorillonitegranulationadsortpionrare earth ion
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