Synthesis The Adsorbent For Extracting Lithium And Research On The Adsorption Process

With the continuous development and progress of science and technology, thedemand for lithium is rising. the development of lithium resources has shifted to thebrine lake and marine resources-liquid lithium resources, which has a greater storagecapacity. Adsorption method is simple and low cost, so it is the most ideal method ofextraction of lithium from brine lakes and oceans. And ion-sieve adsorbent as theadsorption material, which has "memory effect", is considered to be very suitable forthe extraction of lithium from the liquid. Spinel-type manganese oxide as lithiumion-sieve is regarded to be the promising material for the extraction of lithium.KMnO₄as raw material, via the hydrothermal synthesis, high-temperaturecalcination, pickling delithiation eventually synthesized a new spinel-type manganeseoxide lithium ion-sieve---H_1.6Mn_1.6O₄. Then Use X-ray powder diffraction （XRD）and scanning electron microscopy （SEM） to characterize intermediates and finalproduct. And in the process of synthesizing an important intermediate productγ-MnOOH，found that when KMnO₄reacts with ethanol,1-propanol,1-butanol and1,4-butandiol respectively, the products are rod-like MnOOH crystal, and whenKMnO₄reacts with methanol and1,3-propandiol respectively, the products are bothMnOOH crystal and Mn₃O₄crystal, and when KMnO₄reacts with glycol, theproducts are Mn₃O₄.This paper researched on the adsorption, desorption and selective of thesynthetic adsorbent H_1.6Mn_1.6O₄. The results showed that: in appropriate adsorptionconditions, the adsorption capacity of synthetic H_1.6Mn_1.6O₄can reach46mg/g,higher than the literature reported the capacity of other adsorbents; and when theconcentration of desorption liquid is0.5M, the desorption-rate could be95%, anddissolved loss rate is less than3%. After5times re-adsorption and re-desorptionexperiments, the adsorbent adsorption capacity declined slightly, but is always higherthan35mg/g. It shows that the synthetic adsorbent H_1.6Mn_1.6O₄is stable and can bereused. In selective experiments, we investigated K⁺, Na⁺, Mg²⁺on Li+adsorption, theresults shows that the selectivity of adsorbent for Li+is high. For seawater whoseconcentration of Li+is too low （0.17mg/g）, we studied the performance of the adsorbent in low concentration of lithium solution. The results show that the syntheticadsorbent could absorb88%of lithium-ion in10days, and it has a good performancein low-lithium solution. Used precipitation-evaporation methods to the eluate of HClwhich contain the lithium from the adsorbent and re-collected81%of the lithiumresource.Finally, we study on the membrane which contains the adsorbent. The resultsshow that the capacity of adsorbent H_1.6Mn_1.6O₄which is contained in flat membranedecreased, but also be34mg/g.