Studies on Countercurrent Electromigration of Molten Salts with an aim of High Enrichment of <^6Li>

高富集<^6Li>熔盐逆流电迁移研究

基本信息

批准号：
60470160
负责人：
OKADA Isao
金额：
$ 2.37万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

Although enriched <^6Li> is useful, no method has been established in Japan even on a laboratory scale. Countercurrent electromigration of molten salts is promissing for enrichment particularly of isotopes of alkali metals and hence of <^6Li> . However, enrichment of <^6Li> , which is to be held at the cathode, is not so easy as that of <^7Li> because of inevitable low current density there. To avoid this, the method of <^6Li> enrichment around the boundary between molten <LiNO_3> and molten <NH_4> <NO_3> at the cathode was previously devised by us. In this study, electromigration cells of "horizontal type" was made; the separation tube was placed nearly horizontally in which the boundary was established near the relatively large cathode compartment containing molten <NH_4> <NO_3> . The part of the separation tube was heated at about 300 ゜C, while the part of the cathode compartment was heated at about 180 ゜C. Lithium-6 was enriched from 7.4% to 82% in 31 days without corrosion trouble. The enrichment took place around the rather sharp boundary between <LiNO_3> and <NH_4> <NO_3> . The elementry separation factor, that is, the relative difference in internal mobilities of <^6Li> and <^7Li> in neat <LiNO_3> , <LiNO_3> - <NH_4> <NO_3> mixture and <LiNO_3> - <KNO_3> mixture melts, was measured.The effect of mixing on the separation factor is not clear. The separation factor increases with rising temperature. This can be interpreted microscopically with molecular dynamics simulation. The following methods are to be found in the future:(1) detecting the boundary between <LiNO_3> and <NH_4> <NO_3> from the outside and (2) the extracting very small amount of enriched <^6Li> from molten <NH_4> <NO_3> at the cathode. If these are solved, <^6Li> could be enriched more effectively.

尽管富集<^6li>是有用的，但即使在实验室规模上，日本也没有建立任何方法。熔融盐的逆电气迁移预测，特别是碱金属的同位素，因此<^6li>的富集。但是，要在阴极上保存的<^6li>的富集并不像<^7li>的那样容易，因为那里不可避免的低电流密度。为了避免这种情况，我们以前在我们设计了阴极的熔融<lino_3>和熔融<nh_4> <nh_4> <nh_4> <nh_4> <nh_4> <nh_4>之间的<^6li>富集的方法。在这项研究中，制作了“水平类型”的电迁移细胞。分离管几乎被放置在水平的水平上，其中将边界建立在相对大的阴极隔间附近，其中含有熔融<nh_4> <no_3>。将分离管的一部分在约300 c处加热，而阴极室的一部分则在约180°C上加热。锂6在31天内从7.4％富集至82％，而不会腐蚀麻烦。富集发生在<lino_3>和<nh_4> <no_3>之间的相当尖锐的边界周围。元素分离因子，即，在整洁的<lino_3>中，内部迁移率的相对差异，<lino_3>，<lino_3> - <nh_4> <NH_4> <NO_3>混合物和<lino_3> - <kno_3>混合物熔体，测量了混合的效果。分离因子随温度升高而增加。这可以通过分子动力学模拟对显微镜进行解释。将来可以找到以下方法：（1）从外部检测<lino_3>和<nh_4> <no_3>之间的边界，以及（2）在阴极处，从熔融<nh_4> <no_3>中提取了很少的富集<^6li>。如果解决这些问题，则可以更有效地富集<^6li>。