Influence of Fe2O3 and V2O5 on Crystalline Structure of Mg-Al Spinel Synthesized by Waste Aluminum Slag

Mg-Al spinel is synthesized by using industrial waste-residue and basic magnesium carbonate in the aluminum factory as the main raw materials. The influence of V2O5 and Fe2O3 mineralizers on the structure, cell parameters and microscopic morphology of synthesized Mg-Al spinel has been discussed. The Mg-Al spinel is characterized by using XRD, SEM and relevant analytical software, such as Philips plus, Rietveld quantification and so on. The experimental results show that certain amounts of V2O5 and Fe2O3 are beneficial to the formation of Mg-Al spinel, and the optimum addition of V2O5 and Fe2O3 is respectively 2wt% and 3wt%. V2O5 has few effects on cell parameters of Mg-Al spinel; but Fe2O3 can form solid solution with Mg-Al spinel in which Mg-Fe spinel can also dissolve to form continuous solid solution. Therefore, with the increase of Fe2O3 content, the cell parameters of Mg-Al approximately present linear increase.     

Influence of Cr2O3 on the Structure and Property of Mg-Al Spinel Synthesized by Waste Slag in Aluminum Factory

Via the solid phase reaction, Mg-Al spinel has been synthesized by using industrial waste slag from aluminum factory, basic magnesium carbonate and a little amount of clay as the main raw materials. The influences of Cr2O3 mineralizer on crystalline structure, micro-morphology and properties of synthesized Mg-Al spinel are discussed. The synthesized product was characterized by using XRD and SEM, and the relative contents of each crystalline phase are calculated by relevant analytical software such as Philips plus, Rietveld quantification and so on. The experimental results show that a certain amount of Cr2O3 is helpful to the formation of Mg-Al spinel, and when the addition of Cr2O3 is 2.0%, Mg-Al spinel in the system exists in the form of solid solution (Mg0.68Al0.32)(Al0.84Mg0.16)2O4 whose content is the highest reaching 91%. Then the corresponding indexes of each property are as follows: water absorption 3.0%, apparent porosity 9.8%, bulk density 3.36 g·cm-3, and flexural strength 83.32 MPa. Therefore, we can confirm that the optimum addition of Cr2O3 mineralizer is 2.0%.     

反应温度与时间对铝型材厂工业污泥合成堇青石材料的得率与晶相结构影响

本研究主要探讨反应温度和反应时间对铝型材厂工业污泥合成堇青石材料的得率和晶相结构的影响。该污泥系由铝型材表面处理时产生的大量废液, 经沉淀过滤所得。主要成分是一种超细的γ-AlOOH, 其中部分是晶体, 部分是无定形体, 活性很高, 有利于堇青石晶相的形成, 能降低反应温度。 实验结果表明: 堇青石含量随着反应温度升高而增加; 晶相结构和晶胞参数与反应温度有关; 确定1350℃为最佳的反应温度; 反应时间在 2~5 h的试样中,堇青石含量增加, 在5~6 h含量降低. 5 h为最佳的反应时间。