RARE-EARTH METAL, RARE-EARTH ALLOY AND METHOD FOR PREPARING THE RARE-EARTH METAL AND THE RARE-EARTH ALLOY BY MOLTEN SALT ELECTROLYSIS

摘要

The present invention provides a rare-earth metal, a rare-earth alloy and a method for preparing the rare-earth metal and the rare-earth alloy by molten salt electrolysis, wherein in the method for preparing the rare-earth alloy by molten salt electrolysis, a chloride molten salt of an alkali metal or an alkaline earth metal is used as an electrolyte, the anode is an inert electrode or graphite, the cathode is prepared by a rare-earth metal oxide and oxides of other alloy components and/or metal powder and a direct current is introduced to implement electrolysis; during the electrolysis process, the electrolysis temperature is above the melting point of the generated rare-earth alloy and below the melting point of the cathode; the surface layer of the cathode is firstly electrolyzed into a metallic liquid film which falls into a crucible at the bottom after being accumulated to a certain amount; the cathode current density is sufficient for components of the rare-earth alloy to precipitate at the cathode; the electrolysis voltage is lower than the decomposition potential of electrolyte and higher than the decomposition potential of an oxide corresponding to each component of the rare-earth alloy. The rare-earth metal and alloy obtained by the method are in a liquid state and collected by the crucible. The method is environment-friendly with simple process, low energy consumption, high current efficiency and low cost.