Effect of plumbum on the solidification tendency in ordinary Portland cement clinker and its liquid phase properties

Abstract

Using industrial solid waste as raw materials to produce cement clinker is an effective way to reduce environmental impact and disposal costs, however, industrial solid waste may have an impact on the sintering and mineral properties of cement clinker. This paper reports on the tendency of plumbum (Pb) ions to solidify within ordinary Portland cement (OPC) clinker and the effect on liquid phase properties. The results of elemental distributions, phase analysis, and density functional theory (DFT) indicate that Pb ions are most likely to enter C4AF by displacing Fe ions. The further analysis of bond order and bond length (BO-BL) and partial density of states (PDOS) showed that the solid solution tendency of Pb in C4AF can be ascribed to the new bond formation efficiency after Pb ions doping. The effect of Pb ions on the liquid phase properties during the calcination of OPC clinker was investigated experimentally. It was found that an increase in the amount of Pb ions doping lead to an earlier generation of the liquid phase, and the reason for this phenomenon can be attributed to the decrease in the elasticity constant of the mixture of Pb-rich and clinker phases formed by Pb ions doping, which leads to a decrease in the melting temperature. These insights into the doping behaviour of Pb ions will provide meaningful information to guide the use of Pb-containing solid waste as an alternative raw material for the synthesis of OPC clinker.