Method for preparing Gd-Mg intermediate alloy by fluorination system coelectrodeposition

Abstract

The present invention discloses a process for preparing of Gd-Mg intermediate alloy by composite electrodeposition of fluoridated systems. Gd and Mg are electrochemically separated at the cathode of a round or square electrolytic cell with the mixture of 80-95 wt% commercial Gd2O3 (purity higher than 95%) and MgO (purity higher than 95) as the raw material and GdF3-LiF or GdF3-LiF-BaF2 molten fluoride salts as the electrolytic medium and then alloyed to produce Gd-Mg intermediate alloy with the weight percentage of Gd higher than 85 percent. The prepared rear earth magnesium alloy has high magnesium content and uniform ingredients. The present invention has convenient operation that the electrolysis is continuously conducted and the tapping is conducted by the siphon method; the recovery of rear earth is higher than 90 percent, and the exhaust gas meets the requirement of environment protection; the intermediate alloy has low impurity content and low production cost.

Description

Method for preparing Gd-Mg master alloy by co-electrodeposition of fluorinated system technical field The invention relates to a method for preparing a rare earth magnesium master alloy, in particular to a method for preparing a Gd-Mg alloy by co-electrodeposition in a fluoride molten salt electrolysis system. Background technique Gadolinium-magnesium master alloy is mainly used in the preparation of high-performance heat-resistant magnesium alloys, and its service temperature can reach above 300°C. Gadolinium is one of the best elements to improve the heat-resistant properties of magnesium alloys. There are two kinds of molten salt electrolysis systems that can be used for the production of rare earth magnesium alloys by molten salt electrolysis: chloride system and fluoride system. Although some patents have been applied for chloride systems, such as Chinese Patent No. 200510119117.2, Chinese Patent No. 94113824, and Chinese Patent No. 94113824, they all use rare earth ...

AI Technical Summary

Problems solved by technology

When rare earth metals are prepared by electrolysis of fluoride molten salt system, the solubility of rare earth metals in its electrolyte molten salt is smaller than that of chlorides, and rare earth metals and magnesium can be alloyed in a larger composition range. When the rare earth content is less than 30%, the alloy density Below the molten salt of the electrolyte, the alloy will float on the surface of the electrolyte solution to form a liquid cathode. They spread out in a plane and are easily oxidized and burned during the electrolysis process and need gas protection; Magnesium alloys with rare earth content are often mixed with molten fluoride salts and are difficult to separate; in addition, with the change of electrolysis conditions, it is difficult to determine the amount of rare earth precipitated, so the obtained alloy composition is difficult to be uniform

Images