Abstract Recently, with the decrease in the quality of manganese resources, the efficient use of low-quality manganese ore resources has attracted widespread attention. At present, pyrite is often used as reducing agent to recover Mn(IV) in industrialization. However, the passivation of pyrite in the leaching reaction process will lead to a decreased reaction efficiency. Hence, in this study, microwave heating was applied in the reduction system in order to remove the inhibition of the passivation layer and accelerate the dissolution of pyrite, indicating an improvement in the corresponding Mn(IV) reduction efficiency. The results show that the leaching rate assisted by microwave heating was 95.07%, approximately 20% higher than that of conventional heating (75.08%), and the amount of sulfuric acid and pyrite was reduced by 14% and 20%, respectively. XPS analysis shows that there was an obvious sulfur elemental peak at 164.3 eV under traditional heating conditions, but it was absent when microwave heating was applied, and the elemental sulfur under conventional heating is 11.63%, which is higher than that under microwave heating (4.80%). Through scanning electron microscopy, it was noted that there are a large number of voids on the mineral surface under microwave heating, which can increase the solid-liquid contact area, effectively reducing the formation of the sulfur passivation layer and accelerating the dissolution of Mn (IV). In addition, the measurement of the dielectric constant of the solution mixture shows that the dielectric constant of the solution with mineral addition was increased from 36.533 (F/M) to 37.717 (F/M) and the loss tangent angle was increased from 8.61 × 10−3 to 9.21 × 10−3. It can be inferred that microwaves act directly on the mineral itself through the solution. Thus, the application of pyrite and microwave heating in the recovery of Mn(IV) is expected to effectively reduce the use of sulfuric acid, and achieve green, environmentally friendly and efficient leaching of manganese.

中文翻译：

---

微波加热强化硫酸体系中软锰矿-黄铁矿混合物中锰的高效和可持续浸出工艺

摘要 近年来，随着锰资源品质的下降，低品质锰矿资源的高效利用受到广泛关注。目前，工业化中常用黄铁矿作为还原剂回收Mn(IV)。然而，黄铁矿在浸出反应过程中的钝化会导致反应效率降低。因此，在本研究中，在还原系统中应用微波加热以消除钝化层的抑制并加速黄铁矿的溶解，表明相应的 Mn(IV) 还原效率有所提高。结果表明，微波加热辅助浸出率为95.07%，比常规加热浸出率（75.08%）提高约20%，硫酸和黄铁矿用量分别降低14%和20%，分别。XPS分析表明，传统加热条件下164.3 eV处有明显的硫元素峰，而微波加热时不存在，常规加热下的硫元素含量为11.63%，高于微波加热（4.80 %）。通过扫描电镜观察发现，在微波加热下矿物表面存在大量空隙，可以增加固液接触面积，有效减少硫钝化层的形成，加速Mn的溶解。四）。此外，溶液混合物介电常数的测量表明，添加矿物的溶液的介电常数从36.533（F/M）增加到37.717（F/M），损耗角正切角从8增加。61 × 10−3 至 9.21 × 10−3。可以推断，微波通过溶液直接作用于矿物本身。因此，黄铁矿和微波加热在Mn(IV)回收中的应用有望有效减少硫酸的使用，实现锰的绿色、环保、高效浸出。