Hydrogen mineral phase transformation (HMPT) followed by a combined magnetic and flotation process is an innovative technology for the beneficiation of iron-bearing rare earth ores, and it performs superiorly in enhancing the recovery of iron minerals. During the HMPT, the rare earth minerals (particularly bastnaesite) experienced a process of oxidation–reduction-reoxidation, and the reaction behavior and flotation performance of bastnaesite still require further investigation. In this study, suspension roasting, micro-flotation, and relevant analytical tests were used to explore the flotation performance, phase transitions, and surface property variations of bastnaesite stage roasting products. The results showed that all the roasting products were recovered by flotation using different amounts of benzohydroxamic acid (BHA). In the oxidizing atmosphere, the bastnasite decomposition products were Ce7O12 and CeF3, and the specific surface of the products decreased with increasing oxidation temperature, resulting in a gradual decrease in BHA consumption. After the oxidation products were reduced, part of Ce(IV) was converted to Ce(III). As the temperature raised, the BHA consumption initially increased and then decreased. The increased oxygen vacancies at lower temperatures enhanced particle hydrophilicity, which was the reason for the increased BHA consumption. While at higher temperatures, particle fusion and pore closure reduced the specific surface and enhanced hydrophobicity, leading to a decrease in BHA consumption. During the reoxidation stage, the adsorption of oxygen by the reduction products to occupy the oxygen vacancies could reduce BHA dosage and improve the flotation performance. This study demonstrated the flotation performance and characterization evolution of bastnaesite in various stages of roasting, and it provided a certain reference for the optimization of HMPT conditions and efficient recovery of rare earth minerals.

中文翻译：

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氢矿物相变过程中氟碳铈矿的浮选性能及表征演变

氢矿物相变 （HMPT） 后采用磁浮选相结合工艺是一种用于含铁稀土矿石选矿的创新技术，它在提高铁矿物的回收率方面表现出色。在 HMPT 过程中，稀土矿物（尤其是氟碳铈矿）经历了氧化 - 还原 - 再氧化的过程，氟碳铈矿的反应行为和浮选性能仍有待进一步研究。本研究采用悬浮焙烧、微浮选和相关分析测试，探讨了氟碳铈矿阶段焙烧产品的浮选性能、相变和表面性质变化。结果表明，使用不同量的苯并羟肟酸 （BHA） 通过浮选回收所有焙烧产品。在氧化气氛中，氟碳铈矿分解产物为 Ce7O12 和 CeF3，产物的比表面积随着氧化温度的升高而减小，导致 BHA 消耗量逐渐减少。氧化产物还原后，部分 Ce（IV） 转化为 Ce（III）。随着温度的升高，BHA 消耗量最初增加，然后减少。较低温度下氧空位的增加增强了颗粒的亲水性，这就是 BHA 消耗量增加的原因。而在较高温度下，颗粒融合和孔隙闭合降低了比表面积并增强了疏水性，导致 BHA 消耗量减少。在再氧化阶段，还原产物吸附氧气以占据氧空位，可以减少 BHA 用量并提高浮选性能。 本研究证明了氟碳铈矿在焙烧各个阶段的浮选性能和表征演变，为优化 HMPT 条件和高效回收稀土矿物提供了一定的参考。