Understanding the doping behaviors of impurity ions in mineralogical compositions is of great significance for optimizing the quality of sulphoaluminate cement (SAC) clinker as well as its performance in engineering utilizations. The key issue is determining the exact existing state of these impurity ions. Here, combined with experiments and density functional theoretical (DFT) simulations, we systematically studied the substitution preference of chromium in the three main composed phases of SAC clinker, i. e, C₄A₃S̅, C₂S and C₄AF. The formation energies indicate that Cr ions prefer to enter C₄AF by substituting Fe ions followed by incorporating into C₄A₃S̅ with replacement of S ions. The results from X-ray diffractions of single phase show the successful incorporations of Cr ions into both individual mineral, C₄AF and C₄A₃S̅. The dominant content of C₄A₃S̅ in SAC clinker is well illustrated from Rietveld refinement. Further proof of the doping preference is from the difference in relative amounts of Cr(III) and Cr(VI) in SAC clinker samples with lower dosages. More in-depth analyses from both electron contributions and bond order-bond length distributions show that the substitution preference follows the “electronic structure matching” principle, which ensures the effective substitution by forming stronger bonds between guest ions and oxygen atoms. The doping preference provides a possibility of controlling the valence state of Cr ions by tuning the mineralogical compositions of SAC clinker, thus is essential in guiding the synthesis of SAC-based materials by utilizing Cr-bearing solid waste.

了解矿物成分中杂质离子的掺杂行为对于优化硫铝酸盐水泥（SAC）熟料的质量及其在工程应用中的性能具有重要意义。关键问题是确定这些杂质离子的确切存在状态。在这里，结合实验和密度泛函理论（DFT）模拟，我们系统地研究了铬在 SAC 熟料三个主要组成相中的取代偏好，即。e、C ₄ A ₃ S̅、C ₂ S 和C ₄ AF。形成能表明铬离子倾向于进入C ₄通过置换Fe离子AF随后掺入Ç ₄阿₃S̅ 取代 S 离子。单相 X 射线衍射的结果表明，Cr 离子成功地结合到单独的矿物 C ₄ AF 和 C ₄ A ₃ S̅ 中。C ₄ A ₃的主要成分SAC 熟料中的 S̅ 从 Rietveld 细化中得到了很好的说明。掺杂偏好的进一步证明来自具有较低剂量的 SAC 熟料样品中 Cr(III) 和 Cr(VI) 相对量的差异。对电子贡献和键序-键长分布的更深入分析表明，取代偏好遵循“电子结构匹配”原则，通过在客体离子和氧原子之间形成更强的键来确保有效取代。掺杂偏好提供了通过调节 SAC 熟料的矿物组成来控制 Cr 离子价态的可能性，因此对于指导利用含 Cr 固体废物合成 SAC 基材料至关重要。