工艺参数对o-LiMnO2相纯度及Li1.6Mn1.6O4合成的影响及作用
Role of Process Parameters on Phase Purity of o-LiMnO2 and Synthesis of Li1.6Mn1.6O4 as Lithium Ion-Sieve
作者单位E-mail
符雨尧 中南大学冶金与环境学院, 长沙 410083  
杨喜云 中南大学冶金与环境学院, 长沙 410083 yxy7412@csu.edu.cn 
黄海强 中南大学冶金与环境学院, 长沙 410083  
王园园 中南大学冶金与环境学院, 长沙 410083  
李计深 中南大学冶金与环境学院, 长沙 410083  
摘要: 以MnSO4,KMnO4及LiOH为原料,经水热处理后得到LiMnO2,再由固相焙烧得到尖晶石相Li1.6Mn1.6O4,酸洗处理后得到锂离子筛。研究了水热温度,氧气和MnO4-/Mn2+的物质的量之比(nMnO4-nMn2+)对所得LiMnO2的组成及相应前驱体Li1.6Mn1.6O4酸处理中Mn溶损率的影响。开路电势测量及化学分析表明,氧气会参与反应。若按照理论氧化剂用量nMnO4-nMn2+=1:4进行水热反应会导致杂质Li2MnO3和LiMn2O4的生成。若控制水热温度为160℃,nMnO4-nMn2+=1:6时可得到纯相正交LiMnO2o-LiMnO2)。所得离子筛在高镁锂比盐湖卤水中Li+吸附容量可达42.87 mg·g-1,且对Li+具有优异的选择吸附性并遵循化学吸附过程。经过5个循环后吸附容量保持在37.21 mg·g-1,锰溶损率降至0.34%。
关键词: 水热合成  尖晶石相  离子筛  Li1.6Mn1.6O4  锂吸附
基金项目: 国家自然科学基金(No.51574286)、中国博士后科学基金(No.2016M592448)和中南大学博士后基金资助项目
Abstract: Spinel Li1.6Mn1.6O4 was synthesized by hydrothermal oxidation of MnSO4 with KMnO4 to form LiMnO2 following solid-phase roasting. Acid pickling transforms Li1.6Mn1.6O4 to lithium ion-sieve. The effects of hydrothermal temperature, oxygen and molar ratio of MnO4- to Mn2+ (nMnO4-:nMn2+) on LiMnO2 composition and the dissolution percentage of manganese from Li1.6Mn1.6O4 during acid pickling were investigated. Open circuit potential measurement and chemical analysis indicate that oxygen in the air has involved in the hydrothermal reaction to produce LiMnO2 accompanied by formation of Li2MnO3 and LiMn2O4 impurities at a theoretical nMnO4-:nMn2+ of 1:4. Pure orthogonal LiMnO2 (o-LiMnO2) was obtained with a molar ratio of MnO4-to Mn2+ of 1:6 at 160℃. The Li+ adsorption capacity in salt lake brine was 42.87 mg·g-1. The lithium ion-sieve showed excellent adsorption selectivity toward Li+ in salt lake brine and followed a chemical adsorption process. The adsorption capacity remained at 37.21 mg·g-1 and the dissolution percentage of manganese decreased to 0.34% after 5 cycles.
Keywords: hydrothermal synthesis  spinel phase  ion-sieve  Li1.6Mn1.6O4  Li adsorption
投稿时间:2019-09-26 修订日期:2019-11-28
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符雨尧,杨喜云,黄海强,王园园,李计深.工艺参数对o-LiMnO2相纯度及Li1.6Mn1.6O4合成的影响及作用[J].无机化学学报,2020,36(3):536-546.
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