Aluminum Sludge Comprehensive Utilization Of Basic Research

Large amount of milky colloidal solution is produced during the surface treating procedure of aluminum factory, which is usually precipitated and filtered to form a solid state material called waste slag. Average, a medium-level aluminum factory produces about 15 tons of such waste (about 2000 tons of slag) per year. Till now, it still keep a challenge of fully recycle these waste due to its complicate constitutions and high content of impurities.This thesis deals with the characteristics and changing laws under different calcining temperatures of waste slag. Fully chemical analysis technique, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM) were used to characterize the crystalline phases and their changing laws and microstructures and so on.Waste aluminum slag was first time used as main raw material to successfully synthesized high purity cordierite, multite and active alumina in this thesis. Ompared with conventional method, this technique is simple and easily to realize. Because aluminum waste slag has superfine particles and high surface area, it will beneficial to get a higher yield and better quality of products at lower costs. Owing to the high output of and very low cost of raw material, the economic efficiency and social benefit are extremely remarkable. To the best of our knowledge, no reports on using aluminum slag to synthesize cordierite, mullite and active alumina has been reported so far. Therefore, this project can be regarded as an innovationXRD, SEM techniques together with some analysis software such as Philips X'pert plus and Rietveld Quantification software were used to determine the structure details including crystalline phases and structures, crystal defects and sintering mechanism of target productions. The ideal prescriptions for raw materials, TiO2 content and impurities(including Fe₂O₃, CaO, Na₂O and K₂O) were proposed. The results show that the amount of cordierite is up to 100% when TiO₂ mineralizer was added 3.0wt% when sintered at 1350℃for 5h. The reliable experimental data can give a sound foundation for selecting suitable formulas and process control conditions.Two kinds of clay were used to synthesize mullite, similarly, the crystalline structures, crystal defects and microstructures of mullite solid solution were characterized and compared also. The compound tempei-ature can be lowered 200℃or so by using waste aluminum sludge as starting materials. The best technological route was thus determined, and besides, high-quality kiln furniture materials were successfully prepared by using the compound materials. Using pore structure measurement technique, the changes of pore structure of...