The extraction of rare earth elements (REEs) from rare earth fluoride molten-salt electrolytic slag has recently attracted attention because of the potential environmental hazards of this material and its rich content of valuable REEs. In this study, we used a selective nitration method to completely transform powdered samples into a nitrate mixture. We conducted a suitable selective roast-water leaching treatment, which resulted in >98% extraction efficiency for the REEs and Li; oxides of Fe and Al were left behind in the residue, which was attributed to the lower decomposition temperature of Fe(NO₃)₃ and Al(NO₃)₃. Furthermore, F volatilized in the exhaust as HF and was absorbed by an alkaline solution. HSC modeling and TG-DTA were conducted to simulate the nitration process to obtain the optimum conditions for electrolytic slag nitration. Fe, Al, and F impurities were separated from the lixivium to a great extent, thereby enabling the production of REE oxalates with >99% purity. Such a solution could be directly processed to extract metals without the need for pretreatments to remove impurities. The defluorination method and subsequent extraction of REEs and Li from fluoride molten-salt electrolytic slag address the exponential increase in REE production.

从稀土氟化物熔融盐电解渣中提取稀土元素（REE）受到了人们的关注，因为该材料具有潜在的环境危害性，并且其宝贵的REE含量丰富。在这项研究中，我们使用选择性硝化方法将粉末状样品完全转化为硝酸盐混合物。我们进行了合适的选择性焙烧水浸提处理，从而使稀土元素和锂的提取效率> 98％；残留物中残留有Fe和Al的氧化物，这归因于Fe（NO ₃）₃和Al（NO ₃）_3的分解温度较低。。此外，F以HF的形式在排气中挥发并被碱性溶液吸收。进行了HSC建模和TG-DTA模拟硝化过程，为电解渣硝化提供了最佳条件。Fe，Al和F杂质在很大程度上从浸出液中分离出来，从而能够生产纯度> 99％的REE草酸盐。可以将这种溶液直接处理以提取金属，而无需进行预处理以去除杂质。脱氟方法以及随后从氟化物熔盐电解渣中提取REE和Li的方法解决了REE产量呈指数增长的问题。