Structural Properties of Molten CaO-SiO2-P2O5-FeO System

The structural properties of molten CaO-SiO₂-P₂O₅-FeO slag system with varying slag basicity have been investigated by molecular dynamic (MD) simulations using the pairwise potential model. The result shows that more than 95 % Si and 98 % P are four coordinated and form tetrahedral structures. Non-bridging oxygen occupies a predominant position in the system. With basicity increasing from 0.6 to 1.5, the proportion of non-bridging oxygen increases from 66.3 % to 77.3 %, whilst the bridging oxygen decreases from 30.1 % to 10.2 %. Both the result of MD simulations and Raman spectroscopic analysis show the proportion of Q⁰ increases with increasing slag basicity, whilst Q² and Q³ decrease. The degree of polymerization of CaO-SiO₂-P₂O₅-FeO system decreases with increasing slag basicity.