铝厂污泥合成镁铝尖晶石的结构和性能

STRUCTURE AND PROPERTY OF Mg-Al SPINEL SYNTHESIZED FROM WASTE ALUMINUM SLAG

采用铝型材厂污泥和碱式碳酸镁为主要原料合成镁铝尖晶石。从热力学角度探讨了镁铝尖晶石生成的条件。采用X射线衍射及相关软件探讨了不同原料配比对合成产物的影响,并对得到的镁铝尖晶石进行了结构和性能表征。结果表明:各样品中镁铝尖晶石均以固溶体形式(Mg_(0.68)Al_(0.32))(Al_(0.84)Mg_(0.16))_2O_4存在;其晶胞参数变化很小;当MgO与Al_2O_3的摩尔比为1.37时,镁铝尖晶石含量达到最高,为93%(质量分数),其吸水率为0.31%,显气孔率为0.95%,体积密度为3.61 g/cm^3,抗折强度为89.04MPa。

Mg-Al spinel was prepared by using waste slag from an aluminum factory and （MgCO3）4·Mg（OH）2·5H2O as the main starting materials. The formation mechanism and structure of spinel were investigated by X-ray diffraction and analysis software. The influence of composition on the properties of spinel was also discussed. The results show that the synthesized Mg-Al spinel has a composition of （Mg0.68Al0.32）（Al0.84Mg0.16）2O4, which exists in a solid state solution form, and the variation of unit cell parameters is small. When the molar ratio of MgO to Al2O3 is 1.37, the mass fraction of spinel is the greatest, 93%, and the spinel sample has a water absorption of 0.31%, a porosity of 0.95%, a bulk density of 3.61 g/cm3 and a bending strength of 89.04 MPa.