Analysis of Vitrification Processes and Characteristics of Geochang Granite Stone Sludge for Desulfurization Sorbent of MCFC

Abstract

The vitrification processes and characteristics of Geochang granite stone sludge were investigated for the application of desulfurization sorbent of Molten Carbonate Fuel Cell (MCFC). From the X-ray fluorescence analysis (XRF) results using Geochang granite stone sludge, it was confirmed that the network formers (SiO₂ and Al₂O3) in granite stone sludge were present between 83.2 and 87.2 wt% and the rest was comprised of network modifiers (K₂O, Na₂O, CaO, Fe₂O3 and MgO). When Borax (Na₂B₄OSUB7/SUB-10H₂O) was added in the granite stone sludge system for promoting the decomposition and reducing the melting viscosity of refractory SiO₂ and Al2O3 comprising of stone sludge, it was observed that the melting point of the granite stone sludge system was reduced by more than 400°C and the optimized melting temperature for granite stone and borax systems was around 1400°C when comparing X-ray diffraction analysis (XRD) results. Phase transitions and thermal reactions of granite stone sludge systems were also investigated from thermal analysis using Thermogravimetric Analysis (TGA)/ Differential Scanning Calorimeter (DSC).