原位反应生成Sialon结合Al_2O_3-C材料的抗渣侵蚀机理

Mechanism of Slag Corrosion of In-situ Synthesis β-Sialon Bonded Al_2O_3-C Refractory

以电熔白刚玉、单质硅粉和石墨为主要原料,在氮气气氛下1450℃保温4 h原位生成Sialon结合Al2O3-C材料,采用静态坩埚法对烧后的Sialon结合Al2O3-C材料在1600℃下进行抗渣实验。采用XRD分析氮化后Al2O3-C材料的物相组成,用SEM和EDS分别对渣蚀后材料的显微结构和成分进行分析。结果表明:Al2O3-C材料高温氮化后能够生成较多β-Sialon相和少量的Si C相;热力学分析表明,Sialon和Si C本身氧化产生的Si O2和Al2O3,溶解到渣中,降低渣的侵蚀和渗透;SEM结果表明,渣的渗透主要是沿刚玉颗粒边缘进行的,随着渗透的深入,Ca O含量不断下降。

Using high quality fused aluminum, silicon power, and flake graphite as raw materials, the β- Sialon bonded Al2O3-C refractory was prepared at 1450℃ for 4 h under N2 atmosphere. The experiment of slag corrosion resistance for β-Sialon bonded Al2O3-C refractory was carried out with static crucible method. The composition of the sintered sample was investigated by X-ray diffraction （XRD）. The reaction mechanism between slag and refractory was analyzed by thermodynamic analysis. Microstructure and composition analysis of corroded refractory were carried out by Scanning Electron Microscopy （SEM） and Energy Dispersive X-ray Spectroscopy （EDS）. A large number of β-Sialon and a small number of SiC phases were formed in nitrided Al2O3-C material. The thermodynamic analysis indicated that the dissolving into slag of SiO2 and Al2O3 , which was formed due to the oxidation of Sialon and SiC, could effectively increase the viscosity of slag that prevent the further slag corrosion and penetration. The results of SEM indicated that penetration of slag was carried out by reacting with matrix, and with the deep infiltrating, the CaO decreased gradually.