The adsorption characteristics of uranium hexafluoride onto activated carbon in vacuum conditions

The adsorption characteristics of uranium hexafluoride (UF6) on activated carbon have been investigated under vacuum conditions for absolute pressure range of 10–35 mbar. The experiments were carried out for three different types of activated carbon. Evaluation of the experimental data in terms of adsorption kinetic showed that UF6 gas adsorption by three types of activated carbon followed the pseudo-second-order-rate equation very well. The experimental isotherm data were analyzed using the Langmuir, Freundlich, and Henry equations. The results showed that the Langmuir isotherm model fitted the equilibrium data better than the other ones. At a temperature of 20 °C, the maximum adsorption capacity of the first, second, and third activated carbon were 3387, 2198, and 2771 (mg/g), respectively. Adsorption studies were conducted at different temperatures to obtain the thermodynamic parameters. The results depicted the exothermic nature of adsorption and the process was feasible and spontaneous.

► In this study the range of maximum adsorption capacity of UF6 by the activated carbon was measured to be 2198–2771 mg/g. ► The activated carbon is proposed as an adsorbent for adsorption of UF6. ► The Langmuir model is suitable for predicting the adsorption isotherm of UF6 by the activated carbon.