Evaluation of tertiary pyridine resin for the separation of lanthanides by simulated moving‐bed chromatography

Abstract

Lanthanide separation by simulated moving-bed chromatography was studied as a model system for separating lanthanide fission products and minor actinides from used nuclear fuels. The simulated moving-bed system was modeled for a tertiary pyridine anion-exchange resin supported on silica particles as the stationary phase and a mixture of methanol and 1 M nitric acid as the mobile phase. Pulse injection tests using a single packed column were used to obtain chromatographic parameters for mathematical modeling of the simulated moving-bed system. Higher concentrations of methanol improved the separation, but the chromatograms showed evidence of nonlinearity of the isotherms. The mathematical model of the simulated moving-bed process predicted a production rate of purified samarium and neodymium at 118 g solute/L resin/day and a purity of 99.5%. The optimal methanol ratio for the production rate for various product purities was determined from the model. The excellent separation of Nd and Sm suggests that the simulated moving-bed system could be applied to the separation of minor actinides such as americium and curium.

Competitive effect of glucose–fructose adsorption in a fixed‐bed chromatographic column

“…The bed void fraction and the dispersion coefficient were investigated using the pulse injection method of a non‐retained species, blue dextran . The moment analysis method was employed to calculate the first moment (μ, mean residence time), and second moment (σ 2 , variance) of the response chromatographic peak as shown in Eqs.…”