| Abstract |
| A new process to extract Nd from domestic Nd-Fe-B magnet scraps was developed. The scraps were roasted in air and leached with H2SO4. The selective extraction of Nd was investigated in terma of roasting temperature, H2SO4 concentration, and leaching temperature and time. The increase in roasting temperature resulted in a significant reduction in the extraction rate due to the formation of FeNdO3. Nevertheless, Nd could be extracted more selectively since the extraction of Fe was retarded by the concurrent formation of Fe2O3 at higher temperatures. The selective extraction of Nd was observed to increase with shorter leaching time, lower H2SO4 concentration and leaching temperature. The solubility difference between FeSO4 and Nd2(SO4)3 was utilized to precipitate Nd as Nd2(SO4)3, which was separated as residue during the solid/liquid separation process after leaching. When scraps roasted at 700℃ was leached at the pre-determined optimum conditions(H2SO4 concentration: 4M, leaching temperature: 70℃, leaching time: 180 minutes, pulp density 100g/1) about 70% of Nd could be selectively separated as Nd2(SO4)3 precipitates. The Nd/Fe ratio in the precipitate was found to be about 18.33. |
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| Key Words |
| Neodymium, Nd-Fe-B magnet, Scraps, Selective Extraction |
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