Leaching process investigation of secondary aluminum dross: the effect of CO2 on leaching process of salt cake and AlN hydrolysis behavior
For the recycling/disposal of dross/salt cake from secondary aluminum melting, aqueous leaching process offers an interesting economic process route. One of the major obstacles is the reaction between AlN present in the dross and the aqueous phase which can lead to the emission of NH3 gas, as this would pose a serious environmental problem. In the present work, the AlN hydrolysis behavior in NaCl solution was investigated by immersing pure AlN powder in deionized water, 0.3mol/l NaCl aq, 0.6mol/l NaCl aq and NaCl solution with CO2 bubbling at 291K, respectively. Leaching process of salt cake using CO2-saturated water is attempted with a view to absorb the ammonia formed in situ. The results showed that AlN powder underwent enhanced hydrolysis in NaCl aq than that in deionized water, while, the introduction of CO2 was found to hinder the hydrolysis even in the presence of NaCl. Aqueous leaching of salt cake was attempted by CO2-saturated water with a view to absorb the ammonia gas formed in situ. With continuously CO2 bubbling, mass of producing and escaping NH3 decreased irrespective of different conditions, indicating effective hindrance and absorption by carbonized water. The plausible mechanisms for the observed phenomenon are discussed. The retainment of AlN and leaching out of salt open up a promising route towards further processing of dross, viz. development of a process to synthesize AlON from the leaching residues.
CO2 leaching hydrolysis absorption AlN
Peng Li Min Guo Mei Zhang Lidong Teng Seshadri Seetharaman
State key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing,Beijing 10 State key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing,Beijing 10 Department of Materials Science and Engineering, Royal Institute of Technology, SE-10044 Stockholm,
国际会议
Ninth International Conference on Molten Slags,Fluxes and Salts(第九届国际熔渣、溶剂与熔盐学术会议 MOLTEN12)
北京
英文
1-10
2012-05-27（万方平台首次上网日期，不代表论文的发表时间）