Study on the Preparation of Large-Particle Anhydrous Pr-Nd Fluoride with Moderate Apparent Density by Hydrofluoric Acid Preparation Method
Anhydrous Pr-Nd fluoride powder was prepared by hydrofluoric acid precipitation,and the effects of oxalic acid addition,bottom water acidity,supernatant recycling times and hydrofluoric acid dosage on the formation of hydrated Pr-Nd fluoride crystal and the morphology,particle size,apparent density and impurities of anhydrous Pr-Nd fluoride powder were investigated.The results show that the optimized process conditions are as follows:oxalic acid addition at 6％～10％of the theoretical amount(1.5 times the molar amount of RE3+),bottom water acidity of 1.6～2.0 mol/L,supernatant recycling up to 3 times,and hydrofluoric acid dosage at 100％of the theoretical amount(3 times the molar amount of RE3+).The anhydrous Pr-Nd fluoride powder prepared under these optimized process conditions has a median particle size D50 of 10～30 μm and an apparent density of 0.7～0.8 g/cm3.The content of non-rare earth impurities is low,and the yield rate of rare earth reaches 99.81％.
万方数据
维普
