赤泥对电解锰渣中可溶性锰离子固化效果研究

为了探讨赤泥固化电解锰渣中可溶性锰离子的固化效果和可行性，本文采用X射线衍射（XRD）、电子扫描显微镜（SEM）和X射线荧光光谱（XRF）等分析手段，对比评估了新鲜赤泥、陈旧赤泥（堆放1年以上）、生石灰以及陈旧赤泥复合生石灰等固化剂在不同添加剂量下对电解锰渣中可溶性锰离子的固化效果，并初步阐释了赤泥固化电解锰渣中可溶性锰离子的作用机理。结果表明，新鲜赤泥的固化效果优于陈旧赤泥，但差于生石灰；当添加量为30%时，新鲜赤泥对可溶性锰离子的固化率为93.7%，而陈旧赤泥仅为58.6%。这种差异主要是由于陈旧赤泥在堆存过程中部分碱性物质流失所致。另外，30%陈旧赤泥复合5%生石灰时，固化率可达99.8%，与10%生石灰固化效果相近，表明利用赤泥取代部分生石灰同样可以取得较好的固化效果，并且降低了固化成本。总之，赤泥具有作为电解锰渣固化剂的潜力，但考虑到电解锰渣和赤泥还存在其它的危害物质，因此大规模利用时还需要综合评估其使用过程中是否会引起次生风险。

Study on the Solidification Effect of Red-mud on Soluble Manganese Ions in Electrolytic Manganese Slag

This study explored the solidification effect and feasibility of red mud on Mn²⁺ of electrolytic manganese slag, and X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence spectroscopy (XRF) and other analytical methods were used. Fresh red-mud, old red-mud (stacked for more than one year), quicklime, composite of old red-mud and quicklime at different dosages were tested for their solidification effects, and a preliminary explanation on the mechanism of Mn²⁺ solidification by red-mud was presented. The results show that the solidification effect of fresh red mud is better than that of old red mud, but worse than quicklime; when the addition amount of the fresh red mud is 30%, the solidification rate of Mn²⁺ is 93.7%, while the solidification rate with the same addition amount of old red mud is only 58.6%, the loss of some alkaline substances during the storage of old red mud may explain the difference. In addition, when 30% old red mud is combined with 5% quicklime, the solidification rate of Mn²⁺ can reach 99.8%, which is similar to the solidification effect of 10% quicklime, indicating that using red mud to replace part of the quicklime can also achieve comparative solidification effects and reduce the solidification costs. In short, red mud has the potential as a solidifying agent for electrolytic manganese slag, but considering that there are other hazardous substances in electrolytic manganese slag and red mud, it is necessary to comprehensively evaluate whether it will cause secondary risks before large-scale use.