The quality standard for praseodymium neodymium oxide specifies its chemical composition in the national standard XBT206-007, but does not specify its physical properties. The production method of praseodymium neodymium metal is similar to aluminum electrolysis, both using molten salt electrolysis method, and the working principle of the electrolytic furnace is the same. At present, the research on the impact of physical properties of alumina on electrolytic production in the electrolytic aluminum industry is relatively in-depth, and there are also many studies on how to improve the physical properties of alumina to meet the requirements of modern aluminum electrolysis. There are many studies in the rare earth industry on the influence of chemical indicators such as impurities (such as Si, Ca, Fe, S, Cl) and content in praseodymium neodymium oxide on electrolytic production, while there is little research on the physical properties of praseodymium neodymium oxide affecting electrolytic production and improving its physical properties. The physical properties of praseodymium neodymium oxide produced by industrialization vary greatly, and due to their different physical properties, they exhibit different behaviors when applied in the production of praseodymium neodymium metal by molten salt electrolysis. In the process of rare earth electrolysis, the requirements for the physical properties of the raw material praseodymium neodymium oxide mainly include: fast dissolution rate of praseodymium neodymium oxide in the electrolyte and less precipitation at the furnace bottom; Low flying loss and low loss of praseodymium neodymium oxide; Low wear index, high strength, and minimal particle breakage during screening, mixing, transportation, and loading and unloading processes; Good particle flowability. The indicators that characterize the physical properties of praseodymium neodymium oxide mainly include specific surface area, particle size, wear index, etc. A praseodymium neodymium oxide with a high specific surface area has good wetting properties by the electrolyte, fast dissolution rate in the electrolyte, and is not easy to sink to the bottom, resulting in good electrolysis effect. Praseodymium neodymium oxide with a smaller specific surface area indicates a higher degree of burning and increased crystallinity, which reduces its dissolution rate in the electrolyte, resulting in bottom precipitation and further solidification, which is detrimental to electrolytic production and furnace life. 2. Particle size molten salt electrolysis requires uniform particle size of praseodymium neodymium oxide. In general, the particle size is inversely proportional to the specific surface area, that is, the smaller the particle size, the larger the specific surface area. However, if the particle size is too small, it will increase the flying loss of praseodymium neodymium oxide. The particle size of praseodymium neodymium oxide is related to the selection of praseodymium neodymium carbonate precipitant. The particle size of praseodymium neodymium oxide produced with sodium carbonate as precipitant is smaller, while the particle size of praseodymium neodymium oxide produced with ammonium carbonate as precipitant is larger. Praseodymium neodymium metal is the main raw material for producing high-performance neodymium iron boron permanent magnet materials. Its preparation method is to use praseodymium neodymium oxide as the raw material and produce it in an electrolytic furnace by molten salt electrolysis. Using rich praseodymium neodymium oxide (REO) as raw material, NdrPFe alloy was synthesized by electrolysis in fluoride molten salt (BaFZ-LIF-RE3F). The process is reasonable and economically feasible. NdPrFe alloy can be used to prepare NdFeB type permanent magnets with magnetic energy accumulation ranging from 29 to 35 MGOe. The electric furnace is heated by SiC rods and powered by a silicon rectifier for electrolysis. Intended for use in the electromechanical industry
China
