Probing the exact form and doping preference of magnesium in ordinary Portland cement clinker phases: A study from experiments and DFT simulations
Probing the exact form and doping preference of magnesium in ordinary Portland cement clinker phases: A study from experiments and DFT simulations
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DOI：
10.1016/j.cemconres.2021.106420
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发表时间：
2021-06
影响因子：
11.4
通讯作者：
Ruiqi Zhao;Li Zhang;Guangxin Fan;Yang Chen;Gailing Huang;Haibo Zhang;Jianping Zhu;X. Guan
中科院分区：
文献类型：
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作者：
Ruiqi Zhao;Li Zhang;Guangxin Fan;Yang Chen;Gailing Huang;Haibo Zhang;Jianping Zhu;X. Guan
对镁在普通硅酸盐水泥熟料中的存在形态和掺杂行为进行了系统的研究。结果表明，约1.3 wt%的MgO以取代固溶体的形式溶入OPC熟料相中，而过量的Mg则以镁方石的形式积累存在。Rietveld精化结果显示C3S和C3A优于C2S。密度函数理论模拟进一步分析表明，在C3S、C2S和C3A中，取代主要是通过取代Ca离子发生的，而在C4AF中，取代主要是通过取代Fe和Ca离子发生的。随着MgO的增加，结构畸变大，地层能急剧增加，这决定了其溶解度低。本研究对Mg掺杂行为的存在状态和内在机理有了清晰的认识，对利用高Mg石灰石合成OPC熟料具有重要的指导意义。
A systematic study was performed to learn the exact existence form and doping behaviors of magnesium in ordinary Portland cement (OPC) clinker. Our results show that about 1.3 wt% MgO incorporates into OPC clinker phases by forming substitutional solid solutions while excess Mg accumulate and exist as periclase. Results from Rietveld refinement present a substitution preference in C3S and C3A over C2S. More in-depth analyses from density function theoretical simulations show that in C3S, C2S and C3A, the substitution occurs by replacing Ca while in C4AF, it probably occurs by substituting Fe and Ca ions. The large structure distortions and sharp increase in formation energies with increasing MgO determines its low solubility. This work provides a clear understanding of the existence states and the intrinsic mechanism governing doping behaviors of Mg, thus should be very important in guiding the synthesis of OPC clinker by utilizing high-Mg limestone.