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Lithium isotope selectivities of lithium-specific adsorbents

锂专用吸附剂的锂同位素选择性

基本信息

批准号：
05808044
负责人：
OI Takao
金额：
$ 1.22万
依托单位：
Sophia University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Three lithium specific adsorbents have been prepared and their lithium isotope selectivity has been investigated. They were a manganese oxide-based adsorbent designated as MnO_2(Li) prepared by extracting lithium ions from the precursor, LiMn_2O_4, another manganese oxide-based adsorbent, HMnO(2Mg) prepared by extracting magnesium ions from Mg_2MnO_2 and antimonic acid, HSbO_3, with the monoclinic structure prepared by extracting lithium ions from LiSbO_3. Ammonium peroxodisulfate was found to be an excellent extractant of lithium and magnesium ions in the preparation of MnO_2(Li) and HMnO(2Mg). Isotopically, the three adsorbents examined were all ^6Li specific. The magnitude of the lithium isotope effect of MnO_2(Li) slightly decreased with the increase in the degree of manganese dissolution in the process of lithium extraction from the precursor and also decreased with the increase in the lithium/manganese molar ratio in the precursor between Li/Mn=0.5 and 0.8. The maximum separation factor for the lithium isotopes with MnO_2(Li) was 1.014 at 25ﾟC.Various properties of HMnO(2Mg) depended on the degree of magnesium extraction in the process of its preparation. With the increase in the degree of magnesium extraction, the lithium uptake increased, selectivity for the lithium ions increased, but unfortunately the separation factor value decreased. HSbO_3 showed the largest lithium isotope effect among the three adsorbents examined while the amount of lithium uptake was comparable to those of the other two adsorbents. The maximum separation factor value of HSbO_3 was 1.025 at 25ﾟC.However, it was very difficult to extract lithium ions adsorbed in HSbO3, which seemed a serious drawback of HSbO_3 as a lithium isotope separator.

制备了三种锂离子选择性吸附剂，并研究了它们的锂同位素选择性。它们是通过从前驱体LiMn_2O_4中提取锂离子制备的氧化锰基吸附剂MnO_2（Li）、通过从Mg_2MnO_2中提取镁离子制备的另一种氧化锰基吸附剂HMnO（2 Mg）和通过从LiSbO_3中提取锂离子制备的具有单斜结构的锑酸HSb O_3。过硫酸铵在制备MnO_2（Li）和HMnO（2 Mg）中是锂、镁离子的优良萃取剂。从同位素上看，所检测的三种吸附剂都具有^6Li特异性。在Li/Mn=0.5 ~ 0.8的范围内，MnO_2（Li）的锂同位素效应随着锰的溶解程度的增加而略有减小，随着锂锰摩尔比的增加而减小。在25 ℃时，MnO_2（Li）对锂同位素的最大分离因子为1.014。HMnO（2 Mg）的各种性质取决于其制备过程中镁的萃取程度。随着镁萃取程度的增加，锂的吸收量增加，对锂离子的选择性增加，但遗憾的是分离因子值降低。在所考察的三种吸附剂中，HSb O_3表现出最大的锂同位素效应，而吸锂量与其他两种吸附剂相当。在25 ℃时，HSbO_3的最大分离因子值为1.025。然而，吸附在HSbO_3上的锂离子很难被萃取出来，这似乎是HSbO_3作为锂同位素分离剂的一个严重缺点。