Study on recycling of ZM6 rare-earth magnesium alloy scrap by vacuum sublimation gasification

Magnesium (Mg) alloys have great potential for lightweight use and are widely applied in automotive industry. Rare earth magnesium (RE-Mg) alloys, enhanced with rare earth (RE) elements, and their superior properties enable their expanded application in key aerospace components. However, the stringent requirements in aerospace applications lead to lower production yields, inevitably generating a significant amount of RE-containing Mg alloy scrap. Traditional recycling methods risk environmental harm and loss of valuable RE elements. This study proposes a vacuum sublimation gasification process for recycling Mg and neodymium (Nd) from ZM6 RE magnesium alloy. Through thermodynamic analysis, the feasibility of separating and recycling Mg and Nd was evaluated, along with its separation capacity, and the content and behavior of elements in the gas phase were predicted. Experimental results confirm that vacuum sublimation gasification is thermodynamically viable. Under optimal gasification conditions-pressure of 10 Pa, gasification temperature of 750 degrees C, and holding time of 120 min-recycled Mg with a purity of 99.936 wt% and Nd with a purity of 83.84 wt% were obtained. This research provides novel ideas and guidance for enhancing the sustainable circulation of Mg and maximizing the utilization of RE resources.