La_(2)O_(3)对镁质耐火材料抗渣性能的影响

Effect of La_(2)O_(3)on slag resistance of magnesia refractories

为了适应冶金工业对镁质耐火材料具备更优异的抗渣性和更长的使用寿命的需求,采用菱镁矿和La_(2)O_(3)分析纯试剂为原料,对传统的镁质耐火材料进行改性。通过SEM和EDS检测手段,研究了熔渣对含镧镁质耐火材料的润湿行为,以及原位形成的CaLa_(4)(SiO_(4))3O对镁质耐火材料抗渣性能的影响机制。结果表明:通过加入La_(2)O_(3),使材料在烧结后更加致密,同时MgO晶粒长大,增强了对熔渣渗透的抵抗力;相比于未添加试样,添加La_(2)O_(3)能显著提高镁质耐火材料的抗渣侵蚀能力,熔渣对基体的侵蚀深度降低了43.2%;La_(2)O_(3)与熔渣中CaO和SiO_(2)之间发生化学反应生成的高熔点相CaLa_(4)(SiO_(4))3O大大提高了熔渣的黏度,使熔渣与材料基体之间的润湿性变差,降低了熔渣对材料的侵蚀速度。

In order to meet the metallurgical industry's demand for magnesia refractories with better slag resistance and longer service life.In the paper,magnesite and La_(2)O_(3)analytical pure reagents were used as raw materials to modify the traditional magnesia refractories.The wetting behavior of slag on lanthanum-containing magnesia refractories and the influence mechanism of in-situ CaLa_(4)(SiO_(4))3O on slag resistance of magnesia refractories were studied by SEM and EDS.The results show that by adding La_(2)O_(3),the material is denser after sintering,and the MgO grains grow at the same time,which enhances the resistance to slag penetration.Compared with the unadded sample,the addition of La_(2)O_(3)can significantly improve the slag erosion resistance of magnesia refractories:the erosion depth of the slag on the matrix is reduced by 43.2%.The chemical reaction between La_(2)O_(3)and CaO and SiO_(2)in the slag produces the high melting point phase CaLa_(4)(SiO_(4))3O,which greatly increases the viscosity of the slag,makes the wettability between the slag and the material matrix worse,and reduces the erosion rate of the slag to the material.