用碳酸钠沉淀法制备少钕碳酸稀土试验研究

Preparation of Rare Earth Carbonate with Less Neodymium by Sodium Carbonate Precipitation

研究了用碳酸钠沉淀氯化稀土料液制备少钕碳酸稀土,考察了料液中稀土质量浓度、沉淀温度、沉淀时间、水洗温度、水洗时间对少钕碳酸稀土粒度、稀土和氯含量的影响。结果表明:最佳制备工艺条件为料液中稀土质量浓度180 g/L,沉淀温度55℃,沉淀时间270 min,水洗温度55℃,水洗时间45 min;此条件下制备的少钕碳酸稀土为层状堆叠的片状晶体,稀土质量分数>45%,氯质量分数<0.043%,中值粒径D_(50)为29.28μm,粒度分布较为集中。该法成本低,无氨氮污染,通过控制沉淀工艺参数可获得满足市场需求的少钕碳酸稀土产品。

Less neodymium carbonate was prepared by precipitation of rare earth chloride solution with sodium carbonate.The effects of rare earth mass concentration in the feed solution,precipitation temperature,precipitation time,washing temperature and washing time on the particle size,rare earth content and chlorine content of less neodymium carbonate were investigated.The results show that the optimum preparation conditions are:the mass concentration of rare earth in the feed solution of 180 g/L,precipitation temperature of 55℃,precipitation time of 270 min,washing temperature of 55℃and the washing time of 45 min.Under the conditions,the prepared less neodymium carbonate is a lamellar crystal stacked in layers,with the mass fraction of rare earth content of no less than 45%,the mass fraction of chlorine content less than 0.043%and median particle size D_(50)of 29.28μm,and the particle size distribution is relatively centralized.The method has low cost and no ammonia nitrogen pollution.By controlling the precipitation process parameters,less neodymium carbonate products meeting the market demand can be obtained.