为确定草酸铀(Ⅳ)沉淀过程中得到较高沉淀率时的化学工艺条件,采用X荧光法研究了不同酸度(1.0~3.5 mol/L)、温度(30~55℃)、肼浓度(0.1~0.3 mol/L)和草酸浓度(0.05~0.2 mol/L)下草酸铀(Ⅳ)的溶解度(图1)。结果表明:1)保持其他条件不变,仅当酸度为1.5~2.0 mol/L时,草酸铀(Ⅳ)溶解度最低;2)保持其他条件不变,草酸铀(Ⅳ)的溶解度均随温度的升高而增加;3)保持其他条件不变,肼浓度的增加会使草酸铀(Ⅳ)的溶解度增大;4)保持其他条件不变,草酸 In order to determine the chemical process conditions for the precipitation of oxalate oxalate (Ⅳ), the effects of different acidity (1.0-3.5 mol / L), temperature (30-55 ℃), hydrazine concentration ~ 0.3 mol / L) and oxalic acid (0.05 ~ 0.2 mol / L) (Fig. 1). The results show that: 1) the solubility of uranium oxalate (Ⅳ) is the lowest when the acidity is 1.5-2.0 mol / L; (2) the solubility of uranium oxalate (Ⅳ) Increase and increase; 3) keep other conditions unchanged, the increase of hydrazine concentration will make the solubility of uranium oxalate (Ⅳ) increased; 4) keep other conditions unchanged, oxalic acid