沉淀母液和洗液回用的草酸沉淀稀土方法

Recovery of Rare Earth from Mother Liquor and Washing Liquor by Oxalic Acid Precipitation

介绍了一种沉淀母液和洗液的回用的草酸沉淀稀土方法,并系统研究了该方法过程中主要技术参数,如草酸沉淀剂形式、料液与草酸沉淀剂加入形式、沉淀方式、洗涤方式等对草酸稀土质量的影响规律,并确定最佳工艺方案为:草酸沉淀剂配制成溶液与稀土料液采用偏正同沉方式加入反应锅,采用分步沉淀方式控制沉淀过程,并逆流洗涤草酸稀土沉淀。该沉淀方法操作方便、工序简单、沉淀成本低、稀土回收率高、产品质量好,母液和洗液重复利用,减少洗水量,提高水资源利用率,具有很好的经济效益。

A method for recovery of rare earth from mother liquor and washing liquor by oxalic acid precipitation was introduced in the paper.The main technical parameters of the method,such as the form of oxalic acid precipitant,the addition method of feed solution and the oxalic acid precipitant and the way of precipitation and washing were systematically studied to determine their effects on the quality of rare earth oxalate.The optimal process was determined as follows:The oxalic acid precipitant was formulated into a solution and added into the reaction pot with rare earth feed by adopting a positive and negative precipitation method;The precipitation process was controlled by stepwise precipitation method,and the precipitate of rare earth oxalate was washed in a countercurrent washing.The novel method owned lots of advantages,such as easy operation,simple process,low cost,high recovery rate of rare earth and high quality of products.