The solvent extraction and stripping process using Alamine 336 with a case study of uranium
摘要
In this research, a comprehensive study of the solvent extraction of uranium (VI) from acidic sulfate solutions using Alamine 336 diluted in kerosene was scrutinized. The effects of the contact time between the phases, sulfuric acid concentration, extractant concentration, uranium (VI) concentration, organic/aqueous phase ratio, and temperature were investigated. An extraction efficiency of around 99.72% was attained at a sulfuric acid concentration of 0.15 mol L−1, using 0.05 mol L−1 Alamine 336 at 25 °C with an organic/aqueous phase ratio of 1:1. The findings indicated that the extraction of uranium (VI) was a rapid, exothermic, and spontaneous process. The estimated value of Log Kex was 5.92. Parametric variations in the processing parameters indicated a strong impact of the sulfuric acid concentration on the uranium extraction. Uranium (VI) stripping from the loaded organic phase was conducted using many salt and acid solutions in four steps, and the enthalpy change of the stripping reaction was obtained. 99.87% of uranium (VI) loaded in the organic phase was stripped using 0.5 mol L−1 (NH4)2CO3 in a single stripping step. Finally, uranium (VI) extraction from the leach liquor solution was performed under optimal conditions, and the recovery of the loaded organic phase was investigated with different agents. The results showed that uranium purification has a high selectivity coefficient.