Argon oxygen decarburization (AOD) slag represents more than 50 wt% of the slag from stainless steel production. Although some applications are available, e.g., as aggregates for road constructions or fertilizers, they are characterized by low economic value and limited applicability. In order to increase the economic value of AOD slag, alternative applications have been proposed, e.g., as partial or full replacement for Ordinary Portland Cement (OPC). The work presented here investigates whether the adaptation of the AOD slag chemistry within a high temperature process leads to an improvement of its hydraulic properties and thereby can demonstrate its potential to be converted into a hydraulic binder suitable for OPC replacement. For this purpose, three synthetic AOD slags with basicities (CaO/SiO₂) of 2.0, 2.2, and 2.4 were synthesized, and the effect of the CaO/SiO₂ ratio on the material stability, the amount of tricalcium silicate formed, and their hydraulic properties investigated. X-ray diffraction, scanning electron microscope (SEM), and isothermal calorimetry analysis were used to characterize the microstructure and the hydraulic activity. The results show that the proposed method is indeed a promising way to stabilize a stainless steel AOD slag and convert it into a hydraulic binder.

中文翻译：

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不锈钢炉渣向活性胶结剂的转化

氩氧脱碳（AOD）炉渣占不锈钢生产炉渣的50％以上。尽管有一些应用是可用的，例如，作为道路建设或肥料的骨料，但它们的特点是经济价值低，适用性有限。为了增加AOD炉渣的经济价值，已经提出了替代应用，例如，作为部分或完全替代普通硅酸盐水泥（OPC）。此处提出的工作研究了高温过程中AOD炉渣化学物的适应性是否导致其水硬性的改善，从而可以证明其潜力被转化为适合OPC替代的水硬性粘结剂。为此，使用了三种具有碱度的合成AOD炉渣（CaO / SiO ₂合成了2.0、2.2和2.4）的CaO / SiO ₂比对材料稳定性，硅酸三钙形成量及其水硬性的影响。X射线衍射，扫描电子显微镜（SEM）和等温量热分析被用来表征微观结构和水力活动。结果表明，所提出的方法确实是稳定不锈钢AOD炉渣并将其转化为水硬性粘结剂的一种有前途的方法。