We demonstrate an end-to-end protocol for the recovery of Dy and Nd from used NdFeB magnets by following steps- crushing, roasting, grinding, leaching, liquid–liquid extraction and striping. The magnets were roasted over a temperature range of 923–1273 K. The influence of roasting temperature was studied by leaching the roasted samples with HCl solution. Roasting temperature, leaching temperature, leaching time, acid concentration, mixing speed, and pulp density were optimized to selectively leach Nd and Dy while most of the Fe was removed by the hydrolysis of Fe into Fe(OH)₃. Nd and Dy were extracted from the leach liquor using D2EHPA in a two-stage process. First, ~ 95% of Dy was extracted at a pH = 2, and 0.05 M D2EHPA and then Nd was extracted at pH = 4, A/O = 1 with 0.2 M D2EHPA in the second stage. Dy and Nd were completely recovered from the metal-rich organic phase by stripping with varied concentrations of HCl.

我们演示了通过以下步骤从使用过的NdFeB磁体中回收Dy和Nd的端到端协议：粉碎，焙烧，研磨，浸出，液液萃取和剥离。磁体在923–1273 K的温度范围内焙烧。通过用HCl溶液浸出焙烧样品，研究了焙烧温度的影响。优化焙烧温度，浸出温度，浸出时间，酸浓度，混合速度和纸浆密度，以选择性地浸出Nd和Dy，同时通过将Fe水解成Fe（OH）₃去除大部分Fe。。在两个阶段中，使用D2EHPA从浸出液中提取Nd和Dy。首先，在第二阶段中，在pH = 2时萃取〜95％的Dy，然后在0.05 M D2EHPA中萃取Nd，然后在pH = 4时以0.2 M D2EHPA萃取A / O = 1。通过用不同浓度的HCl汽提，可从富金属有机相中完全回收Dy和Nd。