Study On Preparation And Extraction Process Of Rubidium And Cesium Adsorbent Based On Jiangling Brine

In this paper,a new type of inorganic adsorbent ammonium phosphotungstate and TiP2O7 composite was synthesized in the Jiangling sag rich potassium brine concentrate.The research focused on the kinetics and thermodynamics of the adsorption process,and whether it has good special effect orientation selectivity and the stability of recycling,and explore the feasibility of industrial applications.The contents of this work are summarized as follows:(1)TiP2O7,AWP,AWP-TiP2O7 composite adsorption materials were prepared.TiP2O7 was present in the composite ion adsorbent,and the crystal structure of AWP did not change.The median particle size reached 149.99?m.The ideal adsorption conditions were neutral and slightly acidic.(2)The adsorption process conformed to the quasi-secondary kinetic model,and the main rate control step was the intragranular diffusion process.The adsorption behavior of cerium ions on the composite adsorbent was consistent with the Freundlich model.The adsorption of ruthenium by the composite adsorbent was spontaneous and both were exothermic.The entropy change was less than zero during the adsorption process,indicated that the chaos of the solid-liquid interface was reduced,which was the entropy reduction process.(3)When ammonium chloride was used as the desorption solution,the desorption effects of ammonium chloride concentration increased within a certain range,and the desorption effects reached 99.33%when the concentration was 0.5mol/L.(4)In the dynamic adsorption process,the adsorption efficiency increased as the packing height and the penetration time increased.When the other experimental conditions were fixed and the packing height was 1scm,the dynamic adsorption capacities of cerium and lanthanum ions were 1.83mg/g and 1.22mg/g,respectively.As the flow rate of the feed liquid increased,the adsorption capacity of the composite adsorbent decreased,the adsorption efficiency decreased,and the dynamic adsorption capacity decreased.When used the elution solution as ammonium chloride,the peak desorption rate of the composite adsorbent decreased with the increase of the ammonium chloride flow rate.The slower the elution rate,the more complete the elution rate.When the elution rate was 2.5BV/h,the eluent volume was relatively small,and the eluent contained a high concentration of antimony.(5)The content of lanthanum in the mother liquor obtained by evaporation and concentration of brine was 72.77%of the initial brine,and the remaining was 95.08%.The trace elements strontium and barium were highly concentrated,and the enrichment multiples were 13.4 and 15.9,respectively.When the adsorption solution does not contain potassium ions,the saturated adsorption capacity of the composite adsorbent to the ruthenium is 2.12mg/g,1.19mg/g;in the presence of potassium ions,with the increase of potassium ion concentration,the composite material adsorption on the ruthenium.The decrease in capacity indicated that the composite had selective adsorption to ruthenium within a certain concentration range.With the increased of the number of cycles of the composite adsorbent,the adsorption capacity of the regenerated composite adsorbent for cerium ions was gradually reduced,and the potassium ion strontium ion regeneration effects were better.After three times of use,the adsorption capacity of 94.15%and 90.26%can still be achieved,but the combination of cerium ion and composite adsorbent was relatively strong and difficult to desorb.After three times of use,the adsorption capacity was reduced to the initial 51.76%.