The utilization of silicomanganese slag (SMS) for the partial substitution of cement holds significant importance in handling environmental risks and achieving the harmless and resourceful utilization of industrial solid wastes. Nevertheless, an in-depth analysis of the leaching behaviors of heavy metals and the solidification/stabilization mechanisms in SMS and cementitious materials is still lacking. In this study, we adopted the toxicity characteristic leaching procedure and horizontal vibration method to simulate the natural leaching environment, thereby exploring the leaching risks related to heavy metals in the aforementioned materials. The results indicated that the release and migration of heavy metals were highly reliant on environmental pH values. Among them, Mn predominantly existed in SMS in the form of acid extractable fraction, and its dissolution was mainly governed by rhodochrosite and hausmannite. Fortunately, cementitious materials fabricated from SMS can conspicuously prevent the leaching of heavy metals such as Mn, Cr, Ni and As. The mechanism analysis disclosed that heavy metals can be effectively immobilized by silicon-aluminum structures through physical encapsulation, ion exchange, and lattice confinement during slurry hydration, and gradually shift from an unstable state to a more stable one. These findings offer profound insights for the sustainable application of SMS in the environment.

中文翻译：

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硅锰渣中重金属的浸出行为和稳定/凝固表征


利用硅锰渣 （SMS） 部分替代水泥，对于处理环境风险和实现工业固体废物的无害化和资源化利用具有重要意义。然而，目前仍缺乏对SMS和胶凝材料中重金属浸出行为以及凝固/稳定机制的深入分析。本研究采用毒性特征浸出程序和水平振动方法模拟自然浸出环境，从而探索上述材料中与重金属相关的浸出风险。结果表明，重金属的释放和迁移高度依赖于环境 pH 值。其中，Mn 主要以酸性可萃取馏分的形式存在于 SMS 中，其溶出主要受菱锰矿和镰锰矿的控制。幸运的是，由 SMS 制成的胶凝材料可以显着防止 Mn、Cr、Ni 和 As 等重金属的浸出。机理分析揭示了硅铝结构在浆料水化过程中通过物理封装、离子交换和晶格限制可以有效地固定重金属，并逐渐从不稳定状态转变为更稳定的状态。这些发现为 SMS 在环境中的可持续应用提供了深刻的见解。