Research On Modification Of Natural Clinoptilolite And Adsorption Characteristic Of K～+ On Modified Clinoptilolite

Liaoning Province natural clinoptilolite was modified by microwave technology. Physical chemistry characteristics and adsorption thermodynamics and kinetic characteristics of potassium ion on the modified clinoptilolite were made a systematic study. The results can offer certain theoretical foundation on developing and utilizing clinoptilolite such as extracting kali salt from seawater, soil improvement, adsorption-separation kali salt from the mixed salt solution.First, systematic research about modifying clinoptilolite by microwave technology was made. Modified clinoptilolite having high selectivity and more adsorption capacity was obtained after optimizing experiment conditions such as microwave power, irradiation time and chemical composition of modification agent. Physiochemical properties of the modified clinoptilolite were characterized by means of adsorption quality, chemical analysis, FT-IR. and XRD. The results showed that the adsorption potassium ion properties of such prepared clinoptilolite were very excellent from simulation seawater. The valid amount of ion exchange of potassium ion on modified clinoptilolite is more than 30 mg/g which is one time than natural clinoptilolite. There are two microwave modification mechanism, one is aluminium to be incorporated onto the clinoptilolite and the other is calcium and magnesium exchange out of clinoptilolite by ion-exchange. The XRD results showed that the essential framework structures of the modified clinoptilolites were not changed.Second, The potassium ion thermodynamics adsorption on modified clinoptilolite was measured through equilibrium adsorption isotherms. The Freudlich equation, the Langmuir equation and Redlich-Peterson equation were tested using the experimantal data of potassium ion on modified clinoptilolite to obtain the best fit. The influence of the existence of competing cations such as Na+, Ca2+, Mg2+ was measured. The results indicated that Langmuir equation linear fit form can not describe potassium ion adsorption on modified clinoptilolite and It was found that the equilibrium adsorption points in the examined range were most accurately predicted by using Redlich-Peterson curve fit. But mechanism of potassium ion adsorption on modified clinoptilolite can not be explained by Redlich-Peterson curve fit. The selectivity of the modified clinoptilolite to potassium ion is higher than to competing cations. But potassium ionadsorption on modified clinoptilolite was restrained by the existence of competing cations as: Na+>Ca2+>Mg2+.Finally, the potassium ion diffusion mechanism on modified clinoptilolite was analyzed systematically. For this purpose two ways were utilized, which were Moving Bounding Model and Broken Phase Contact Experiment. The results proved that potassium ion diffusion on modified clinoptilolite was controlled by film diffusion control at lower potassium ion concentration and by particle diffusion control at higher potassium ion concentration and by film and particle diffusion control jointly at middle potassium ion concentration. The diffusion mechanism judged by kinetic data of potassium ion on modified Clinoptilolite at different stirring speeds was unanimous with above-made conclusions. Potassium ion diffusion rate on modified clinoptilotile was also influenced by temperature and particle radium. Two kinds of methods can complement each other, prove each other.