氧化镧对菱镁矿风化石制备镁铝尖晶石组成结构的影响

以菱镁矿风化石与工业氧化铝为原料,按照尖晶石理论组成对两种物料进行配料,添加不同数量的氧化镧,分析研究氧化镧对以菱镁矿风化石为原料制备的镁铝尖晶石组成结构、结晶度、晶胞常数的影响,用XRD分析法和SEM法对烧后试样的相组成和显微结构进行研究。利用X’Pert Plus软件对试样中结晶相的相对结晶度进行计算,并对镁铝尖晶石相的晶胞常数进行分析。结果表明,以菱镁矿风化石为主要原料制备出的镁铝尖晶石材料中主晶相镁铝尖晶石的晶胞常数随着氧化镧加入量增加而增大。当氧化镧加入量为0.8%～1.0%时,镁铝尖晶石晶胞常数增加趋势减弱。加入氧化镧可以提高材料中结晶相结晶度,当氧化镧加入量达到0.8%时,材料中结晶相结晶度是未加入氧化镧的1.1667倍。结构中镁铝尖晶石的分布更为均匀。

Influence of Lanthana on Composition and Structure of Mg - Al Spinel Material Prepared from Decomposed Magnesite

Mg-Al spinel was prepared using decomposed magnesite and industrial alumina as raw materials.The effect of lanthana on composition,cell parameters,crystalinity and microstructure of crystalline phases,microstructure of Mg-Al spinel was studied.XRD and SEM were used to characterize the crystalline phase and microstructure.The crystalinity and cell parameters of the crystalline phases were estimated by X’Pert plus software.The experimental results show that the cell parameter and lattice volume of the main crystalline phase Mg-Al spinel in the Mg-Al spinel material prepared from decomposed magnesite increase along with lanthana addition.When the lanthana addition was 0.8%~1.0%,the increasing trend of the cell parameter lessened.Lanthana can be avail to the crystallinity of crystalline phase.When lanthana addition was 0.8%,the crystallinity of crystalline phase was 1.1667 times as much as that of specimen without lanthana,and more uniformity Mg-Al spinel appeared in the structure.