Thermodynamic Analysis for the Refining Ability of Salt Flux for Aluminum Recycling

Materials

Takehito Hiraki²  Takahiro Miki²  Kenichi Nakajima¹  Kazuyo Matsubae²  Shinichiro Nakamura³ 

[1] Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, Tsukuba 305-8506, Japan; E-Mail:;Graduate School of Engineering, Tohoku University, Sendai 980-8578, Japan; E-Mails:;Graduate School of Economics, Waseda University, Tokyo 169-8050, Japan; E-Mail:

关键词: recycling of aluminum;    thermodynamic analysis;    impurity removal;    salt flux;    refining ability;   

DOI  :  10.3390/ma7085543

来源: mdpi

【 摘 要 】

The removability of impurities during the aluminum remelting process by oxidation was previously investigated by our research group. In the present work, alternative impurity removal with chlorination has been evaluated by thermodynamic analysis. For 43 different elements, equilibrium distribution ratios among metal, chloride flux and oxide slag phases in the aluminum remelting process were calculated by assuming the binary systems of aluminum and an impurity element. It was found that the removability of impurities isn’t significantly affected by process parameters such as chloride partial pressure, temperature and flux composition. It was shown that Ho, Dy, Li, La, Mg, Gd, Ce, Yb, Ca and Sr can be potentially eliminated into flux by chlorination from the remelted aluminum. Chlorination and oxidation are not effective to remove other impurities from the melting aluminum, due to the limited parameters which can be controlled during the remelting process. It follows that a proper management of aluminum scrap such as sorting based on the composition of the products is important for sustainable aluminum recycling.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.