High Temperature Performance of Al₂O₃–SiO₂–SiC–C Ramming Refractory While Using Al and BN Additives

摘要

High temperature experiments were carried out to investigate the effect of aluminum and BN addition on the performance of Al_(2)O_(3)–SiO_(2)–SiC–C ramming refractory against slag attack. The slag utilized was a typical ironmaking one composed of 45.4% SiO_(2), 36.6%CaO, 15.9% Al_(2)O_(3) and balanced by MgO, P_(2)O_(5) and S. The temperature was set at 1823 K. Infrared (IR), Scanning Electron Microscopy-Energy Dispersive Spectrometer (SEM-EDS) and X-ray Diffraction (XRD) results show that Al is very effective in inhibiting CO and CO_(2) gas formation resulting from the main in-situ reaction between silica and carbon in the mix and consequently improving the slag corrosion resistance of the material. On the other hand, the sample with BN addition becomes more porous and hence exhibits a deteriorated resistance against slag attack compared to the standard refractory sample due to the fact that the decomposition of BN releases gases. The post-mortem analysis of refractory samples from the Siphon Box of a Cupola Furnace after intense industry service was conducted using an X-ray and SEM-EDS to compare physical properties and the degradation mechanism between the samples after industry service and those used in high temperature laboratory experiments. The resonance of the results for both types evidences the validity of applying knowledge obtained in the current research to actual industrial processes.