Electrorefining and Recycling of Magnesium

研究了电精炼工艺在MgC12-NaCl-CaC12和MgC12-NaCl-KCl熔盐中提纯镁和回收废镁的应用。用伏安法测定了镁和Fe、Ni等杂质元素的电化学行为，并推导了电精炼镁的必要条件。在电化学测定结果的基础上，对镁进行了电精炼。该工艺有效地去除了金属镁中的杂质元素，并确定了合适的电解条件。由于镁合金是通过电精炼提纯的，因此可以应用于镁及其合金的回收。研究还表明，以MgCu合金为阳极的三层电解可以实现更高效的电解。在含稀土金属氯化物的相同熔盐体系中，还研究了合金元素（如稀土金属）与Mg的co -e电沉积。稀土金属与镁金属电沉积，其含量可由电解条件控制，如盐中氯离子的浓度。含有与电解相同数量稀土金属的Mg金属具有良好的耐蚀性。结果表明，稀土金属与Mg共电沉积可用于镁合金的生产。

The application of electrorefining process for the purification of Mg and for the recycling of Mg scrap has been studied in MgC12-NaCl-CaC12 and MgC12-NaCl-KCl molten salts. The electrochemical behaviors of Mg and impurity elements, such as Fe and Ni, were measured by voltammetry, and the necessary conditions of the electrorefining of Mg were deduced. The electrorefining of Mg was carried out on the basis of the result by the electrochemical measurement. By the process, impurity elements were removed from Mg metal effectively, and the suitable electrolysis condition was revealed. Because Mg alloys were purified by the electrorefining, this process can be applied for the recycling of Mg and its alloys. It was also shown that the more efficient electrolysis can be actualized by the so-caalled three-layer electrolysis where MgCu alloy was used as anode.Co-e1ectrodeposition of alloying elements, such as rare earth metal, with Mg has been also studied in the same molten salt system including rare earth metal chlorides. Rare earth metals were electrodeposited with Mg metal, and their contents can be controlled by the electrolysis conditions, such as the concentration of their chloride in the salts. The Mg metal including the same amount of rare earth metals as those by electrolysis showed good corrosion-resistivity. It is concluded that the co-electrodeposition of rare earth metals with Mg can be available for the production of Mg alloy.