Thermodynamic assessment and experimental validation of clinker formation from blast furnace slag through lime addition

In the present study thermodynamic simulation of chemistry modification of blast furnace slag by lime addition to obtain clinker composition has been carried out. The effects of lime addition on each mineralogical phase under the equilibrium are simulated using FactSage 6.4 thermodynamic software. The critical value of lime addition in slag for each mineralogical phases and its effect on liquidus temperature of the slag has been reported. The desired cementitious phase namely belite has been observed beyond 14.4% of lime addition. A decreasing trend is observed in the liquidus temperature of the mixture from 1530 °C to 1497 °C for the lime addition of 15-24%. The simulation results were further validated by experiments conducted on blast furnace slag in the laboratory. Energy-Dispersive X-ray Spectroscopy analysis were used to qualitatively estimate the mineralogical phases formed after melting of the slag mixtures in the laboratory followed by air cooling.