Insights on Substitution Preference of Pb Ions in Sulfoaluminate Cement Clinker Phases

The doping behaviors of Pb in sulfoaluminate cement (SAC) clinker phases were systematically studied combined with density functional theoretical simulations and experiments. The results present that, in the three composed minerals of C(4)A(3)S, C(2)S, and C(4)AF, Pb ions prefer to incorporate into C(4)A(3)S by substituting Ca ions. Further analyses from partial density of states, electron density difference, and local distortions show that such doping preference can be attributed to the small distortions as Pb introduced at Ca sites of C(4)A(3)S. The results and clear understandings on the doping behaviors of Pb ions may provide valuable information in guiding the synthesis of Pb-bearing SAC clinker, thus should draw broad interests in fields from sustainable production of cement and environmental protection.