An Environmentally Friendly Process Involving Refining and Membrane-Based Electrolysis forMagnesium Recovery from Partially Oxidized Scrap Alloy
出版年: Oct. 2013
Magnesium is recovered from partially oxidized scrap alloy by combining refining and solid oxide membrane (SOM) electrolysis. In this combined process, a molten salt eutectic flux (45 wt.% MgF 2-55 wt.% CaF 2) containing 10 wt.% MgO and 2 wt.% YF 3 was used as the medium for magnesiumrecovery. During refining, magnesium and its oxide are dissolved from the scrap into the molten flux. Forming gas is bubbled through the flux and the dissolved magnesium is removed via the gas phase and condensed in a separate condenser at a lower temperature. The molten flux has a finite solubility for magnesium and acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium recovered has high purity. After refining, SOM electrolysis is performed in the same reactor to enable electrolysis of the dissolved magnesium oxide in the molten flux producing magnesium at the cathode and oxygen at the SOM anode. During SOM electrolysis, it is necessary to decrease the concentration of the dissolved magnesium in the flux to improve the faradaic current efficiency and prevent degradation of the SOM. Thus, for both refining and SOMelectrolysis, it is very important to measure and control the magnesium solubility in the molten flux. High magnesium solubility facilitates refining whereas lower solubility benefits the SOM electrolysis process. Computational fluid dynamics modeling was employed to simulate the flow behavior of the flux stirred by the forming gas. Based on the modeling results, an optimized design of the stirring tubes and its placement in the flux are determined for efficiently removing the dissolved magnesium and also increasing the efficiency of the SOM electrolysis process.
作者地址: Xiaofei Guan; Pal, U.B.; Div. of Mater. Sci. & Eng., Boston Univ., Brookline, MA, USA.
Powell, A.C.; INFINIUM Inc., Natick, MA, USA.
类别 / 分类
研究方向:Metallurgy & Metallurgical Engineering; Engineering; Environmental Sciences & Ecology; Business & Economics (由 Thomson Reuters 提供)
国际专利分类:C22B Production or refining of metals; Pretreatment of raw materials; C25 Electrolytic or electrophoretic processes; Apparatus therefor
分类代码:E3636 Metallurgical industries; E1710 Engineering materials; E0230 Environmental issues; E1525 Industrial processes