摘要
An innovative process was proposed to recover metallic aluminum from secondary aluminum dross(SAD)by alkali roasting−water leaching.Thermodynamic calculations and experimental results were used to illustrate the phase transformation and reaction mechanism of the alkali roasting process.The leaching behaviors of roasted residue were also analyzed.Under optimal conditions,the aluminum extraction rate reached 93.08%.In addition,the kinetics of the water leaching of roasted products was studied through shrinking core model,and it was revealed that the leaching process of aluminum was in accord with diffusion control.The apparent activation energy of the leaching process was calculated to be 3.44 kJ/mol.Based on the above study,the underlying mechanism of the alkali roasting−water leaching was clarified.
提出一种采用碱法焙烧−水浸强化回收二次铝渣中金属铝的创新工艺。利用热力学计算和实验结果阐明了碱焙烧过程的相变和反应机理,并对焙烧产物的浸出行为进行了研究。在最佳条件下,铝的提取率达到93.08%。此外,利用收缩核模型对焙烧产物的水浸动力学进行了研究,发现焙烧产物中铝的浸出过程受扩散控制;同时计算得到浸出过程的表观活化能为3.44 kJ/mol。并且,在此基础上解释了二次铝渣碱性焙烧−水浸的反应机理。
基金
the financial support from the National Natural Science Foundation of China(Nos.51804342,51874356)
the National Key R&D Program of China(Nos.2019YFC1907301,2020YFC1909203)
the Innovation Driven Project of Central South University,China(No.2020CX038).
