Recycling high-grade rare earth polishing powder waste (REPPW) is crucial for protecting the environment and sustainable utilization of rare earth resources. Leaching REPPW in the eco-friendly H₂O₂-H₂SO₄ suffers from the lack of understanding of the leaching mechanism. Here, the leaching mechanism was investigated under the optimal leaching conditions, i.e., T = 353 K, L/S ratio = 40 mL/g, H₂SO₄ concentration = 4 mol/L and initial H₂O₂ concentration = 0.8 mol/L, by which leaching efficiency of Ce and La reached 99.3% and 99.1%, respectively. Furthermore, pseudo steady state kinetic analysis suggested a five-step leaching mechanism involving CeO₂ hydroxylation, H₂O₂-CeO₂ coordination, $\equiv \mathrm{Ce}\left(\mathrm{III}\right)-{\mathrm{H}}_2{\mathrm{O}}_2$ deprotonation, $\equiv \mathrm{Ce}\left(\mathrm{IV}\right)-\mathrm{H}{\mathrm{O}}_2^{-}$ reduction and $\equiv \mathrm{Ce}\left(\mathrm{III}\right)-\mathrm{H}{\mathrm{O}}_2^{\ast }$ protonation, which was verified by the agreement between experimental data and the proposed reaction model. This work proposes a leaching mechanism of REPPW and would help develop an effective and sustainable recycling process for rare earth secondary resources.

回收高品位稀土抛光粉废料（REPPW）对于保护环境和稀土资源可持续利用至关重要。在环保的H中浸出REPPW₂O₂-H< /span> = 353 K，L/S比 = 40 mL/g，H< /span> 浓度 = 4 mol/L 和初始 H₂配位， ₂-CeO₂O 羟基化、H₂浓度 = 0.8 mol/L，则Ce和La分别达到99.3%和99.1%。此外，伪稳态动力学分析表明，存在五步浸出机制，涉及 CeO₂O₂₄SO₂T 缺乏对浸出机制的了解。这里，在最佳浸出条件下研究浸出机理，即，₄SO₂$==铈\left(\mathrm{三、}\right)-{\mathrm{H}}_2{\mathrm{氧}}_2$去质子化，$==铈\left(\mathrm{四号}\right)-\mathrm{H}{\mathrm{氧}}_2^{-}$减少和$==铈\left(\mathrm{三、}\right)-\mathrm{H}{\mathrm{氧}}_2^{*}$质子化，实验数据与所提出的反应模型之间的一致性验证了这一点。这项工作提出了 REPPW 的浸出机制，有助于开发一种有效且可持续的稀土二次资源回收工艺。