Studies On The Physcial Chemical Properties Of Natural Clinoptilolite From Chicheng Hebei And Specialities Of K～+-NH₄～+ Exchange On Clinoptilolite

The physical chemical properties of natural clinoptilolite from Chicheng Hebei were studied, and the experiments of K+-NH4+ exchange were made taking clinoptilolite as exchanger. Mainly including: the selection of mine, the determination of the adsorption quantity of K+ in seawater , the effects of different treated ways on the physical chemical properties of natural clinoptilolite , the studies of K+-NH4+ exchange thermodynamics and kinetics .The results of experiments showed that Chicheng clinptilolite belonged to high Si/Al ratio, the adsorption of K+ in seawater was 18mg/g clinoptilolite. Compared with the original clinoptilolite ,the adsorption quantity of K+ in seawater on the treated sample was less. The analysis of XRD and TEM showed that characteristic peak intensity reduced . The ability of cation exchange was 198.3mmol/100g clinoptilolite.The studies of K+-NH4+ exchange thermodynamics showed that the selectivity of K+ was higher than NH4+,and with temperature increasing it was in favor of NH4+ selectivity, the K+-NH4+ ion exchange reaction was endothermic reaction ,and △rGmθ>0, it showed that in the reaction of ion exchange NH4+entered clinoptilolite phase was weaker than K+.Through the study of K+-NH4+ exchange kinetics ,we could draw the conclusions that the exchange process was controlled by film diffusion in the condition of experiment, and with the increase of operation temperature and the improving of operation flow velocity, the transform ratio of clinoptilolite improved in the same contact time, and with the increasing of the viscosity, the adsorption ratio of NH4+on K-clinoptilolite reduced. Temperature and flow velocity had more effect on the total mass transformation coefficient(KD), from 25 ℃ to75℃, the total mass transfer coefficient(KD) was increased near twice; flow velocity from 0.0312m/s to 0.2604m/s, the total mass transfer coefficient(KD) was increased more than four times, but viscosity had a little effect on KD. According to the judgement of mass transfer mechanism, the mass transfer model was founded, and in condition of experiments the data from the model could be fit for the data got from the experiments very well.