釹鐵硼永磁體工業廢料之化學沉澱與萃取回收稀土

Recovery of Rare Earths from Neodymium Iron Boron Magnet Waste by Chemical Precipitation and Solvent Extraction

劉韋麟(Wei-Lin Liu)

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(2020年)

摘要

稀土在產業上的應用具有相當的普遍性及重要性，導致稀土的需求與價格都不斷的在上揚，美國能源部發布的關鍵度矩陣圖裡，最關鍵的元素都是稀土元素，由此可知稀土的影響力，加上本國並無稀土礦藏，因此更顯得稀土的回收重要性，目前國內並無稀土之永磁材料的回收廠，也無相關輕稀土（釹、鐠）、重稀土（鏑、鋱）的分離技術，導致即使回收也造成資源純度與價值大減。
本研究主要探討釹鐵硼永磁體工業廢料中輕重稀土的分離技術，先以鹽酸選擇性溶解法溶解出稀土後，加入草酸沉澱，再以高溫鍛燒轉化為氧化稀土，氧化稀土再以溶劑萃取法進一步分離輕重稀土，來提升產品的價值。
本研究著重於溶劑萃取法分離輕重稀土，選擇P507為萃取劑，氫氧化鈉為皂化劑，最佳萃取參數為：萃取平衡pH值為1、反萃液鹽酸酸濃度為2N、重稀土與萃取劑莫耳比為1:26.31、油水相比為1:2，稀釋劑比萃取劑為5.85、最佳單級重稀土萃取率為86.11%、純度為97.13%、分離係數為759.63。

關鍵字

溶劑萃取 ； 稀土 ； 永磁體

並列摘要

The application of rare earths in the industry is quite universal and important, leading to rising demand and prices of rare earths. In the criticality matrix released by the US Department of Energy, the most critical elements are rare earth elements. Unfortunately, the influence of rare earth! There is no rare earth mineral deposit in the country, so the recovery of rare earth is more important. At present, there is no recycling plant for permanent magnetic materials of rare earth in Taiwan, and there is no related separation technology of light rare earth (neodymium, gallium) and heavy rare earth (dysprosium, ytterbium). As a result, even the recycling will cause the resource purity and value to be greatly reduced.
This study mainly discusses the separation technology of light and heavy rare earths in industrial waste of NdFeB permanent magnets. The rare earths are first dissolved by hydrochloric acid selective dissolution, added with oxalic acid precipitation, and then converted to rare earth oxides by high temperature calcination, and the rare earth oxides are then extracted with solvents The method further separates light and heavy rare earths to enhance the value of products.
This study focuses on the separation of light and heavy rare earths by solvent extraction. P507 is selected as the extraction agent and sodium hydroxide is the saponification agent. The optimal extraction parameters are: extraction equilibrium pH is 1, back extraction liquid hydrochloric acid concentration is 2N, heavy rare earth and extraction The molar ratio of the agent is 1:26.31, the oil-water ratio (dilution dose) is 1:2, the diluent ratio extractant is 5.85, the optimal single-stage heavy rare earth extraction rate is 86.11%, the purity is 97.13%, and the separation factor is 759.63.

並列關鍵字

solvent extraction ； rare earth ； permanent magnet

參考文獻

1.王文裕，「鋰電池及磁性元件中關鍵金屬材料循環技術研發」，科技部專題研究計畫(2017)。

2.王玉、王蕊、王彤、于微、萬飛，「8-羥基喹啉與酸性膦萃取劑(C301)對稀土元素的萃取」，吉林地質，第35卷，第4期，第106-109頁(2016)。

3.王長君，「強化產業能力以因應中國大陸國內需求」，日本經濟新聞，3月(2011)。

4.王毅軍、劉宇輝、郭軍勳、王素玲、翁國慶，用鹽酸優溶法從NdFeB 廢料中回收稀土，濕法冶金，第25卷，第4期，第195-197頁(2006)。

5.朱屯，萃取與離子交換，冶金工業出版社，北京，第177-180頁(2005)。