氢氟酸沉淀法制备松装密度适度的大颗粒无水氟化镨钕的研究

Study on the Preparation of Large-Particle Anhydrous Pr-Nd Fluoride with Moderate Apparent Density by Hydrofluoric Acid Preparation Method

采用氢氟酸沉淀法制备无水氟化镨钕粉体,考察了草酸加入量、底水酸度、上清液循环利用次数、氢氟酸用量等条件对水合氟化镨钕晶体的形成和无水氟化镨钕粉体的形貌、粒度、松装密度、杂质等的影响。结果表明,优化的工艺条件为:草酸投入量为理论用量(RE^(3+)物质的量的1.5倍)的6%~10%,底水的酸度为1.6~2.0 mol/L,上清液循环利用次数≤3次,氢氟酸投入量为100%理论用量(RE^(3+)物质的量的3倍)。采用优化工艺条件制备的无水氟化镨钕中位粒径D_(50)可达到10~30μm,松装密度为0.7~0.8 g/cm^(3),非稀土杂质含量低,稀土收率达到99.81%。

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 RE^(3+)),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 RE^(3+)).The anhydrous Pr-Nd fluoride powder prepared under these optimized process conditions has a median particle size D_(50)of 10~30μm and an apparent density of 0.7~0.8 g/cm^(3).The content of non-rare earth impurities is low,and the yield rate of rare earth reaches 99.81%.