Computational Study of the Transport Properties of Molten CaO-SiO2-P2O5-FeO System

MD simulations have been accomplished to study the transport properties of molten CaO-SiO2-P2O5-FeO system. The self-diffusion coefficients of Ca, Si, P, Fe and O ions increase with increasing slag basicity and FeO content, while decrease with increasing P2O5 content. The diffusivities of these ions in the quaternary melts follow the sequence of Ca>Fe>O>P>Si. The calculated viscosities are in good agreement with the experimental ones. It is obvious that increasing the amount of network formers (e.g., Si and P ions) leads to larger viscosity and degree of slag polymerization, while adding network modifiers (e.g., Fe and Ca ions) causes viscosity and slag polymerization to decrease. Except for the calculation, the FT-IR analysis also confirmed the relationship between structural properties of the slag and composition. The viscosity of the slag increases linearly with increasing the parameter of Q(Si+P).