关键词: 低碳经济, 镁碳材料, 铝粉, 供气元件, 镁砂, MgAlON

Abstract: From the perspective of low-carbon economy,antioxidant aluminum powder was introduced as a raw material to explore its influence on the phase composition and microstructure of low-carbon magnesia-carbon materials in high temperature N₂,which aimed to prepare low-carbon gas-supply elements suitable for the bottom-blowing process of steel-making furnaces.The samples were prepared using fused magnesia,flake graphite and aluminum powder as raw materials and phenolic resin as the binder,with the aluminum powder addition of 5%,8% and 12%,by mass,respectively.The phase composition and microstructure of the samples were characterized and analyzed by XRD,SEM and EDS after nitrogen heat treatment at 1 300,1 400,1 500 and 1 600 ℃.The results show that with aluminum powder as the raw material,the magnesium-carbon samples exhibit a phase evolution different from the traditional ones,and the changes in the contents of aluminum and graphite make the modified phases on the surface of magnesia particles different.In the sample with 15% graphite and 5% aluminum powder,the modified phase is aluminum-doped cubic magnesia crystals.As the aluminum powder addition increases to 8% and above,Al₇C₃N₃ disappears,while Al₆O₃N₄ appears,whose formation temperature is higher than 1 400 ℃.In the sample with 5% graphite and 8%-12% aluminum,the modified phase is a magnesium aluminate spinel solid solution containing N element (MgAlON).

Key words: low-carbon economy, magnesia-carbon materials, aluminum powder, gas-supply elements, magnesia, MgAlON