CO2和O2地浸铀矿原液中SO2-4的快速测定

为改良现有硫酸钡比浊法测定含铀浸出液中SO^2-₄不能长时间稳定均匀地形成硫酸钡悬浊液的缺点，采用吸光比浊法研究不同波长、酸度、稳定剂、无水乙醇用量对硫酸钡分散体系稳定性的影响以提高测量准确度。实验结果表明，改良比浊法测定SO^2-₄浓度体系中的最佳实验条件为1.0 mL HCl（3 mol/L）、5.0 mL聚乙烯醇溶液(含w=10%BaCl₂?2H₂O)、3.0 mL 无水乙醇。在最佳波长440 nm处，SO^2-₄质量浓度在0.2~1.5 g/L范围内符合比尔定律。该方法的检出限为 0.003 6 mg/L，定量限为 0.012 0 mg/L（n=20）。该方法样品测量回收率为99.0%~99.8%，加标相对标准偏差为 0.63%~2.44%(n=2)。与 GB/T 5750.5-2006 国标法比较，该方法操作简便、快捷，结果准确度高，在CO₂和O₂地浸采铀浸出原液SO^2-₄浓度的测定中有广阔的应用前景。

Rapid Determination ofSO2-4 in CO2 and O2 In-Situ Leaching Uranium Solution

In order to improve the shortcoming that the BaSO4 suspension cannot be stably and evenly formed by SO^2-₄ for a long time in the lixivium containing uranium with the use of BaSO₄ turbidimetry, the impact of different wavelengths, acidity, stabilizers and the dosage of ethyl alcohol absolute on the stability of the dispersed system of BaSO₄ by using light absorption turbidimetry was analyzed, which is to improve the accuracy of the measurement. The results show that the best experimental condition for the system which measures the concentration of SO^2-₄ by using the improved turbidimetry is the system which include 1.0 mL HCl(3 mol/L) , and 5.0 mL 50 g/L ［C₂H₄O］n(containing w=10%BaCl₂?2H₂O) and 3.0 mL CH₃CH₂OH. The concentration of SO^2-₄ conforms to Beer Lambert law in the range of 0.2-1.5 g/L when being at 440 nm of the optimized wavelength. The detection of this method is limited to be 0.003 6 mg/L and the limit of the ration is 0.012 0 mg/L(n=20). The recovery rate of this method is 99.0%-99.8% and the relative standard deviation is 0.63%-2.44% (n=2). Compared with GB/T 5750.5—2006, this method is easy to operate and it is quick. What’s more, the accuracy of the results is high. Therefore, there is a promising future for this method to be applied widely in the measuring of the concentration of SO^2-₄ in the lixivium in CO₂ and O₂ in-situ uranium mining.