Preparation of Aluminum Hydroxide from Industrial Residue of Aluminum Alloy Surface Treatment Process
WANG Xiao LIU Qing-fen WANG Ya-qi HUANG Xiao-zhu ZHANG Chao
Key Laboratory of Green Process & Engineering，Institute of Process Engineering Chinese Academy of Sciences Key Laboratory of Green Process & Engineering，Institute of Process Engineering Chinese Academy of Sciences Key Laboratory of Green Process & Engineering，Institute of Process Engineering Chinese Academy of Sciences Key Laboratory of Green Process & Engineering，Institute of Process Engineering Chinese Academy of Sciences Key Laboratory of Green Process & Engineering，Institute of Process Engineering Chinese Academy of Sciences
Abstract：Preparation of aluminum hydroxide from industrial residue of aluminum alloy surface treatment process was studied. The leaching process of Al from the industrial residue by NaOH solution and precipitation of Al(OH)3 from Al leaching solution by H2SO4 were explored. The effects of the concentration and dosage of alkali or acid, reaction temperature and time were examined. Process optimization was obtained by orthogonal experiments. The chemical composition, morphology and quality of Al(OH)3 product were examined as well. The results showed that the Al content in the dry residue was 28.7%, and Al existed as the form of Al(OH)3 crystal in the industrial residue. The optimum conditions of leaching process were the molar ratio of NaOH addition to Al(OH)3 in the industrial residue 2.88:1, reaction temperature 75℃, and reaction time 55 min. At these conditions, the maximum yield of aluminum in leaching process reached up to 97.5%. At the optimal conditions of precipitation process of Al(OH)3, such as the molar ratio of H2SO4 addition to AlO2- in leaching solution (0.95~1.10):1 and pH value 5.5, the precipitation yield of Al(OH)3 reached up to 89.2%, and the total recovery rate of aluminum was obtained by 87.1%. The Al(OH)3 product was amorphous with the diameter of particles of about 17 mm. The purity of Al(OH)3 in the product was up to 95.5%.
2014, Vol. 14 
