Construction of Recovery and Recycling System for Rare Metals by Centrifugal Partition Separation Method

溶剂萃取和高效离心分配色谱（HPCPC）是金属化学处理和回收的基础研究。本研究的目的是建立一个程序，可以减少废料，并促进再利用的产品制造。此外，它被认为是环境保护和自然资源的有效利用，可以通过我们的investments.First，我们已经研究了相互分离的碱土金属离子的HPCPC使用0.16 M的双-2-乙基己基次膦酸在庚烷（BEHPA）作为固定相。用氯乙酸水溶液（pH6.5和5.3）移动的流动相两步洗脱负载的四种金属离子。将乙醇（5%）加入到pH 6.5的移动的相中以分离Sr（II）和Ba（II）。色谱条件为2，136个分配通道、800 rpm转速和1.5 ml/min流速。洗脱曲线 ...更多信息 本文研究了以二-2-甲基壬基磷酸/庚烷为固定相的HPCPC对Cu（Ⅱ）、Mn（Ⅱ）、Co（Ⅱ）、Ni（Ⅱ）等金属离子的分离。采用两步洗脱法，改变氯乙酸移动的相的pH值，使四种过渡金属离子相互分离。流速为2.0 ml/min，以0.16 M BEHPA/庚烷为固定相，采用两步HPCPC法可以分离Fe（III）、Zn（II）、Mn（II）、Co（II）和Ni（II）等过渡金属离子。乙酸盐、氯乙酸盐和酒石酸盐缓冲液用作移动的相。发现当样品溶液通过泵连续输送到固定相时，共存的Co（II）-Ni（II）混合溶液中的Co（II）被选择性地保留。因此，HPCPC法净化Ni（II）溶液具有一定的应用前景，并对轻、中稀土离子进行了HPCPC分离的尝试。从BEHPA的萃取研究中可以预期，在常规流速下，这些金属的HPCPC分离相当困难。La（Ⅲ）-Ce（Ⅲ）-Pr（Ⅲ）、Eu（Ⅲ）-Sm（Ⅲ）和Gd（Ⅲ）-Tb（Ⅲ）-Dy（Ⅲ）混合物在pH值分别为2.95、2.30和1.55时相互分离。沉淀、离子交换、膜过滤分离可与HPCPC结合用于实际和化学处理，用于金属的回收和再循环过程作为下一步的研究。进一步的研究正在进行中，以建立废物和沃茨中金属的回收和再循环系统。少

The fundamental studies on chemical treatment and recycling of metals have been undeftaken by solvent extraction and high performance centrifugal partition chromatography (HPCPC). The aim of this investigation is to establish the procedure that the waste materials can be reduced and be promoted to reuse for manufacturing of products. Furthermore, it is considered that environmental protection and efficient use of natural resources can be performed through our investigations.First, we have investigated the mutual separation of alkaline earth metal ions by HPCPC using 0.16 M bis-2-ethylhexylphosphinic acid in heptane (BEHPA) as a stationary phase. Two-step elution of the four metal ions loaded was accomplished with aqueous chloroacctic acid mobile phase (pH 6.5 and 5.3). Ethanol (5%) was added to the pH 6.5 mobile phase for the separation of Sr(II) and Ba(II). The chromatographic conditions were 2,136 partition channels, 800 rpm rotation speed, and 1.5 ml/min flow rate. The elution curve … More was obtained by monitoring the absorbance of each metal complex post-tabled with a chromogenetic agent.The separation of such metal ions as Cu(II), Mn(II), Co(II) and Ni(II) has been investigated by HPCPC employing di-2-methylnonylphosphoric acid/heptane as a stationary phase. The four transition metal ions have mutually been separated by the two-step elution method, changing the pH of the chloroacetic acid acid mobile phase. The flow rate was 2.0 ml/min.Such transition metal ions as Fe(III), Zn(II), Mn(II), Co(II) and Ni(II) can be separated by the two-step HPCPC method using 0.16 M BEHPA/heptane as a stationary phase. Acetate, chloroacetate and tartrate buffers were used as mobile phases. The coexisting Co(II) in a mixed Co(II)-Ni(II) solution was found to be selectively retained when the sample solution was continuously delivered into the stationary phase by a pump. Thus, the purification of Ni(II) solution by the present HPCPC method would be applied in the field of nickel battery industry.The light and middle rare earth metal ions were attempted for HPCPC separation. It can be expected from extraction studies with BEHPA that the HPCPC separation of these metals is rather difficult at a conventional flow rate. We have tried to separate them at a slower flow rate of 0.2 ml/min. La(III)-Ce(III)-Pr(III), Eu(III)-Sm(III) and Gd(III)-Tb(III)-Dy(III) mixtures were mutually separated at pH 2.95, 2.30 and 1.55, respectively.From the above results, it was found that the HPCPC method was very useful for the separation of metal ions investigated at a laboratory scale. Precipitation, ion exchange, membrane filter separation can be combined with HPCPC for actual and chemical treatments for recovery and recycling process of metals as the next step of investigation. Further studies are in progress to construct the system of recovery and recycling of metals in waste materials and waters. Less