添加剂在镁铝尖晶石原料合成中的作用

发布时间：2018-06-28 23:55

本文选题：镁铝尖晶石 + 添加剂　；参考：《耐火材料》2017年06期

【摘要】：综述了稀土氧化物(Y_2O_3、La_2O_3、Nd_2O_3和CeO_2等)、氟化物(CaF_2、MgF_2、AlF_3)、其他氧化物(ZnO、TiO_2和SnO_2等)以及复合添加剂(B_2O_3+TiO_2及B_2O_3+氟化物)等在镁铝尖晶石原料合成中的作用。引入合适的稀土氧化物可形成液相,促进镁铝尖晶石在较低温度下形成和结晶;氟化物中的F-掺入晶格中取代O2-,增大了阳离子空位浓度,增强了阳离子的扩散,促进尖晶石的形成;合适的复合添加剂也可促进镁铝尖晶石的合成。但添加剂对镁铝尖晶石合成过程中化学反应热力学和动力学的影响,对不同化学计量的镁铝尖晶石晶体结构、晶格常数和晶粒度大小等的影响,以及高温不同气氛下添加剂对镁铝尖晶石化学稳定性、致密度等的影响还需进一步深入系统研究。
[Abstract]:The role of rare earth oxides (YS _ 2O _ 3, La _ 2O _ 3, Nd _ 2O _ 3 and CeO _ 2, etc.), in the synthesis of magnesium spinel raw materials by fluorides (CaF2MgF2AlF3), other oxides (ZnO- tio _ 2 and SnO _ 2), and composite additives (B2O3TiO2 and B2O3 fluoride) are summarized in this paper. Introducing suitable rare earth oxides can form liquid phase, promote the formation and crystallization of magnesia-aluminum-spinel at lower temperature, and increase the concentration of cationic vacancy and the diffusion of cations by substituting for O _ 2-in the crystal lattice of fluoride. The formation of spinel and the synthesis of MgAl spinel can also be promoted by suitable compound additives. However, the effects of additives on chemical reaction thermodynamics and kinetics, crystal structure, lattice constant and grain size of different stoichiometric magnesia-aluminite spinel were studied. The effects of additives on the chemical stability and density of magnesia-aluminum-spinel in high temperature and different atmospheres need to be further and systematically studied.
【作者单位】：河南省高温功能材料重点实验室;
【基金】：国家自然科学基金面上项目(51672253) 河南省重点科技攻关项目(152102410014) 河南省科技厅基础研究项目(162300410044)
【分类号】：TQ175.4

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