中文摘要：

根据柠檬酸（H2cit）与稀土形成稳定的溶于水的配合物，从而达到与磷沉淀分离的目的。采用正交回归实验设计方案，考察了H2cit加入量、pH值、温度、沉淀时间对磷回收率的影响。结果表明，H2cit加入量为0．05mol·L^-1，pH=10，温度为30℃，沉淀时间为20min时磷的回收率达到99．5％，此时稀土的损失率仅为0．98％。另外，采用XRD分析方法对碱化沉淀进行分析，确定了碱化过程的反应。

英文摘要：

Citric acid coordinated with rare earth elements, and the coordination products dissolved in water. So in this paper, the citric acid was used to separate rare earth with phosphorus. The relationship among the ratio of phosphorus recovery, citric acid addition,pH, temperature, and time was studied by the quadratic regression orthogonal analysis, and then the regression equation was obtained. The optimum process conditions of phosphorus recovery were obtained as follows：citric acid addition： 0.05mol ·L^-1 , pH ： 10, temperature：30℃, and time： 20min, the ratio phosphorus recovery： 99.5%, rare earth loss： 0.98%. In addition, XRD analysis was used to investigate the sediment, and the reaction of alkality process was determined.