Extraction of An(Ⅲ) and Ln(Ⅲ) From Simulated High Level Liquid Waste by Me-TODGA

N,N,N',N'-tetraoctyl-3-oxapentanediamide(TODGA) is the most studied extractant among diglycolamides, but its extraction ability for An(Ⅲ) and Ln(Ⅲ) is too strong, making the stripping of An(Ⅲ) and Ln(Ⅲ) is difficult. In this paper, a novel diglycolamides process employing N,N,N',N'-tetraoctyl-2-methyl-3-oxapentanediamide(Me-TODGA) was designed as the extractant. The process was verified using simulated high level liquid waste(SHLLW). The results show that the extraction rate of trivalent and tetravalent metal ions exceeds 99.5% after 6-stage extraction and 10-stage scrubbing. After 16-stage stripping with 0.3 mol/L nitric acid, the stripping rates of An(Ⅲ) and Ln(Ⅲ) are over 95%, the stripping rate of Zr⁴⁺ is 68.0%, and the concentrations of other metal ions are all lower than 2.1% of the initial concentration. This process enables efficient stripping of An(Ⅲ) and Ln(Ⅲ) under higher acidity (0.3 mol/L nitric acid), which reduces the generation of interfacial crud, and provides basic data for the design and application of the diglycolamides process.