球形MnO2·0.5H2O提锂性能及其机理研究

Performance and Mechanism of Recovering Lithium from Aqueous Solution by Spherical MnO2·0.5H2O

中文关键词:  尖晶石型Li1.6Mn1.6O₄  MnO₂·0.5H₂O  锂回收  吸附容量  吸脱附机制

英文关键词:Spinel Li1.6Mn1.6O₄  MnO₂·0.5H₂O  Lithium recovery  Adsorption capacity  Adsorption-desorption mechanism

中文摘要:

      考察了形貌对尖晶石型锂离子筛吸附剂MnO₂·0.5H₂O吸附性能的影响。实验证明,反应物Mn₂O₃的形貌在很大程度上决定了前驱体及其吸附剂的形貌。采用XRD、SEM、TEM、FT-IR、XPS和N₂吸附—解吸等温线等对样品进行了表征。表征和吸附实验结果表明,与立方形锂离子筛相比,球形锂离子筛具有较高的吸附容量(42.46 mg/g),同时对溶液中的Li⁺具有较高的选择性。表面脱质子和离子交换过程的共同作用增强了离子筛型吸附剂的提锂Li⁺性能。此外,本文对Li1.6Mn1.6O₄与MnO₂·0.5H₂O的吸附—解吸机理进行了解释。

英文摘要:

      The influence of morphology on the adsorption capacity of spinel-structured MnO₂·0.5H₂O lithium ion-sieves(LISs)prepared by the treatment of a Li1.6Mn1.6O₄ precursor in HCl was experimentally investigated.The obtained samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and N₂ adsorption-desorption isotherms.Spherical LISs were demonstrated to have a higher adsorption capacity(up to 42.46 mg/g)and selectivity toward Li⁺ in solution than their cubic counterparts.As a result,the morphology of reactant Mn₂O₃ was determined to largely determine the morphology of the precursor prepared by a typical two-step solid-phase reaction and its corresponding adsorbent.Additionally,the results presented here indicate that both surface deprotonation and ion-exchange processes of the as-prepared sieve-type adsorbent contribute to its enhanced Li⁺adsorption performance.