電透析協同錯合反應分離水中鈷離子與鎳離子

Separation of Cobalt(II) and Nickel(II) from Aqueous Solution by Electrodialysis Synergized Complexation

秦孝德(Hsiao-Te Chin)

指導教授 ： 王文裕

朝陽科技大學/理工學院/環境工程與管理系/碩士(2016年)

摘要

鈷及鎳均為重要的工業原料，兩者廣泛應用於合金、電池、催化劑，以及其他眾多產品，鈷、鎳的需求量及純度越來越高，很多新的分離技術被用於鈷的分離純化，本研究提出之電透析協同錯合反應即是重要的一環。
國內營運中的廢電池回收廠僅處理鋅錳電池與鹼錳電池，回收的鋰電池則採境外處理，在新型三元系鋰電池回收利用化學沉澱法時，使鈷、鎳共沉澱，導致回收金屬純度與價值大減。
本研究利用電透析技術進行鈷鎳分離實驗，由於在SCN-溶液中，Co(II)能與SCN-形成Co(SCN)42-錯合物，而Ni(II)不能形成離子錯合物，陽離子交換膜可鎳陽離子透過，而無法讓錯合的硫氰酸鈷離子透過，經由電透析作用使其分離，進而實現鈷，鎳分離。
本研究結果發現SCN-系統對鈷鎳進行分離實驗，最佳參數為金屬水相/硫氰酸銨體積比5、槽液溫度為25℃、鈷鎳莫耳比為1：1，金屬與硫氰酸銨莫耳比1：4；在此條件下，鈷萃取率可高達92%，而對鎳的萃取率只有5%，最終能夠達到鈷鎳分離。

關鍵字：鈷、鎳、錯合物電透析、萃取、錯合物

關鍵字

鈷 ； 鎳 ； 錯合物 ； 電透析 ； 萃取

並列摘要

Cobalt and nickel are important for industrial material, due to its wide application in alloy, batteries, catalysts, and many other products. The demands of quantity and higher purity are increased. Many new technologies are develop for extracting and separating of cobalt and nickel. Electrodialysis synergized complexation is the innovative technology developed by this study.
At present the battery recovery plants in Taiwan only reclaim manganese batteries and alkaline zinc-manganese dioxide batteries. The spent lithium-ion batteries are all exported outside the border. When chemical precipitation method was employed to recovery metals from the new type of NMC(LiNiO2/LiCoO2/LiMn2O4) lithium-ion batteries the three metals co-precipitated and produced a low value material.
In this study, electrodialysis synergized complexation technology was developed for separation of Co(II) and Ni(II). As Co(II) forms CoSCN42- complex in SCN- solution, CoSCN42- can’t transport through cation exchange membrane. Ni(II) in SCN- solution retains cation form and could not transport through cation exchange membrane. The different electric charge of CoSCN42- anionic complex and Ni(II) cation can be separated by electrodialysis with anion exchange membrane.
The result showed that Co(II) and Ni(II) in SCN- solution can be separation by electrodialysis synergized complexation, the optimum operation parameters are aqua (material)/NH4SCN volume ratio of 1：5, 25℃, material molarity ratio of 1：1 and NH4SCN molarity ratio of 1：4. The resulting extraction ratio of Co(II) is 92% and Ni(II) is 5%, respectively.
Keyword：Cobalt, Nickel, Electrodialysis, Extraction, Complexation

並列關鍵字

Cobalt ； Nickel ； Electrodialysis ； Extraction ； Complexation

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