二氧化锆对低品位菱镁矿制备镁铝尖晶石材料组成结构的影响

以低品位菱镁矿与工业氧化铝为原料制备镁铝尖晶石材料,分析研究二氧化锆对以低品位菱镁矿为原料制备的镁铝尖晶石的组成、结晶度、晶胞参数和微观结构的影响,用XRD和SEM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参数进行分析。结果表明:适量引入二氧化锆有利于以低品位菱镁矿与工业氧化铝为原料制备镁铝尖晶石材料;材料中结晶相的结晶度随二氧化锆加入量的增加呈现出先增加后降低的现象;镁铝尖晶石材料中主晶相镁铝尖晶石的晶胞参数及晶胞体积受到锆离子的置换固溶作用的影响;当二氧化锆加入量为1.2%时,镁铝尖晶石的晶胞参数和晶胞体积最大,结构中镁铝尖晶石形成量最大,而玻璃相形成量最小。因此对于以低品位菱镁矿与工业氧化铝为原料制备的镁铝尖晶石材料,二氧化锆的最佳引入量为1.2%。

Influence of Zirconia on Composition and Structure of Mg-Al Spinel Material Prepared by Low-grade Magnesite

Mg-Al spinel was prepared using low-grade magnesite and industrial alumina as raw materials according to the theory composition of Mg-Al spinel.The effect of zirconia 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 phases and microstructure.The crystallinity and cell parameters of crystalline phases were estimated by X’ Pert plus software.The experimental results showed that appropriate zirconia addition was prone to preparation of the Mg-Al spinel materials from low-grade magnesite and industrial alumina.With the increase of zirconia,the crystallinity of crystalline phase firstly increased and then decreased.The cell parameter and lattice volume of major phase Mg-Al spinel were effected by replacement solid solution of Zr4+.When the zirconia addition was 1.2%,the cell parameter and lattice volume of major phase Mg-Al spinel were maximum,the mount of Mg-Al spinel was maximum,and the mount of glass phase was minimum.The optimum addition mount of zirconia into the Mg-Al spinel materials prepared from low-grade magnesite and industrial alumina was 1.2%.