【作者】 王小敏；

【导师】 陈日耀；

【作者基本信息】 福建师范大学 ， 环境工程， 2008， 硕士

【摘要】 我国盐湖卤水中蕴含着十分丰富的金属锂资源。盐湖卤水中的锂是与大量的钾、镁等离子共存的,而高的Mg/Li比值增大了利用盐湖卤水资源生产锂盐的难度。本研究应用溶胶凝胶法制备了尖晶石结构的MnO₂离子筛,该离子筛对锂离子呈现出高效选择性和高交换容量。研究了Li/Mn比、焙烧温度和酸浸脱过程对二氧化锰离子筛前驱体和离子筛结构的影响;运用XRD、IR等表征方法研究了MnO₂晶相结构和形成机理:通过等温吸附曲线、吸附动力学及选择性吸附等实验研究了离子筛的吸附性能,并讨论了二氧化锰离子筛结构与吸附性能之间的关系;最后用不同浓度的盐酸洗脱实验研究其脱附效果。制备并研究了α、β、γ、δ四种晶型二氧化锰的晶体结构并应用于对锂离子的吸附。实验结果表明:α-MnO₂的吸附效果最好,且具有很高的吸附选择性。研究了温度对α-MnO₂吸附锂离子的影响,并通过吸附动力学来研究α-MnO₂的吸附性能。并应用于模拟海水和模拟盐湖卤水中锂离子的吸附,表现出良好的优先选择吸附性能。采用流延成型法,以Ca²⁺改性海藻酸钠（SA）和戊二醇交联的壳聚糖（CS）为前驱体,制备改性m（SA-CS）聚合物双极膜,并用红外光谱、扫描电镜、热重测定、机械性能测定、溶胀度测定等手段对双极膜进行表征。将实验制备出的改性双极膜应用于分离不同价态的金属离子,以表观迁移速率表征离子的迁移特性。实验结果表明,m（SA-CS）双极膜能高效地将一价金属离子和二价金属离子等分离,从而排除了二价金属离子(如Mg²⁺)对分离提取锂离子的干扰。更多还原

【Abstract】 The lithium resource is rich in the saline bittern water in china,but the saline bittern water also contains abundant magnesium ion and kalium ion,which can influence the extraction of lithium ion.Spinel LiMn₂O₄ precursor and MnO₂ ion-sieve were synthesized via the Sol-Gel method.MnO₂ ion-sieve appears a high selectivity and exchange ability for lithium ion.The influences of Li/Mn ratio,the calcination temperature and acid leaching process on manganese dioxide precursor and the structure of ion-sieve were systematically studied.The surface composition、bulk phase and structure of the material were characterized by XRD、IR methods.The Li⁺ exchange ability and selectivity of ion-sieves were inverstigated via adsorption isotherm and kinetics.The relationship between ion-sieve structure,the adsorption properties and the effect of hydrochloric acid concentration on Li⁺ elution have also been discussed.The crystal structures of the four kinds of manganese dioxide have been discussed and used to adsorb the lithium ion.α-MnO₂ appears a good adsorption ability and selectivity.The influence on adsorption for lithium ion has been investigated at the different temperatures,α-MnO₂ shows a predominate adsorption for lithium ion in the simulant seawater or bittern water.m（SA-CS）bipolar membrane was prepared by sodium alginate（SA）and chitosan （CS）,which were modified by Ca²⁺and glutaraldehyde（GA）as linking reagents, respectively.It was characterized by FTIR、SEM、TG、mechanism performance and swelling degree,m（SA-CS）bipolar membrane was used as septum in the separation of ions.The immigration rates of ions were obtained.The experimental results show that m（SA-CS）bipolar membrane can separate the different valence metal ion.Using this characterstic,it can remove divalent metal ions from bittern water,advoiding Mg ion’s interference on lithium ion adsorption.更多还原