新型复合生物质锂吸附剂的制备及吸附性能研究

Study on the Preparation and Adsorption Properties of A Novel Composite Biomass Carbonaceous Adsorbent for Li+

中文关键词:  生物质吸附剂  锂  吸附  卤水

英文关键词:Biomass carbonaceous adsorbent  Lithium  Adsorption  Salt lake brine

中文摘要:

      以KMnO₄、苯胺、LiOH和生物质碳气凝胶(BCA)为原料,通过水热沉积法得到了锰酸锂(LMO)负载的生物质碳气凝胶(BCA@LMO),并用HCl酸洗后得到了BCA@HMO复合锂吸附剂。利用IR、XRD、XPS、SEM、EDS、Mapping、BET等手段对其结构进行了表征。考察了pH值、离子强度、初始浓度、温度和吸附时间对锂吸附的影响。结果表明,复合吸附剂为介孔结构,其孔道内和表面具有丰富的锰酸锂颗粒,Li⁺的最大平衡吸附量在pH=12时为4.07 mmol·g-1,吸附过程符合Langmuir等温线和准二阶动力学模型,升高温度和碱性环境利于Li⁺的吸附。吸附机理为H⁺与Li⁺的离子交换。复合吸附剂较好地改善了锰系锂吸附剂固液分离困难的问题,该吸附剂在实际南翼山盐田和东台吉乃尔盐田卤水(2.92 mmol·g-1)中具有良好的吸附性能。因此,该吸附剂在卤水锂的分离中具有良好的应用价值和潜力。

英文摘要:

      A composite adsorbent named BCA@HMO was synthesized by modifying BCA with potassium permanganate,aniline,lithium hydroxide,and biomass carbon aerogel through a hydrothermal deposition method.The composite adsorbent was characterized by IR,XRD,XPS,SEM,Mapping,EDS and BET.The adsorption isotherm,kinetics,the effects of pH,temperature,initial lithium concentration,and the ionic strength on lithium adsorption were studied.The results show that the adsorbent has mesoporous structure and on the surface abound polyhedron particles which main component is proved to be lithium manganate.The maximum equilibrium adsorption capacity was 2.92 mmol g-1.The adsorption isotherm and adsorption kinetics were best fitted with the Langmuir model and pseudo-second-order rate equation,respectively.The increase of temperature and alkaline environment are beneficial to the adsorption of Li⁺.The adsorption performed through the ion-exchange between H⁺ and Li⁺.The composite adsorbent can improve the difficulty of solid-liquid separation of manganese lithium adsorbent.The adsorbent has good adsorption capacity in the brine of Nanyishan salt field and East Taijinar salt field(2.92 mmol·g-1).Therefore,the adsorbent has good application value and potential in the separation of lithium brine.