Patent Number: 051805260
Section: description

The invention is illustrated by, but not limited to, the following Examples. EXAMPLE 1 Six hundred liters of solvent (comprising 120 liters of Tributyl Phosphate (TBP) and 480 liters of odourless kerosene) were taken from the Recovery Line solvent extraction plant in the production of nuclear grade uranium and washed with 4% aqueous sulphuric acid until free from uranium. The solvent and aqueous streams were fed counter-currently through a series of box mixer-settlers, at a solvent to aqueous ratio of 2:1 to effect washing. The solvent was then passed at 1.5 liters an hour (0.5 Bv/hr) through an ion-exchange column containing 3 liters of Amberlyst A21. The RU value (as hereinbefore described) of the solvent was reduced from 189 .mu.gU/ml to 11 .mu.gU/ml by passing the solvent once through the ion-exchange resin. EXAMPLE 2 900 ml of solvent (comprising 180 ml of TBP and 720 ml of odourless kerosene) from the Recovery Line solvent extraction plant was washed repeatedly with 2% sulphuric acid in a series of box mixer-settlers as in Example 1, until free from uranium. The solvent was then passed at 1.5 ml/hr (0.1 Bv/hr) through an ion-exchange column containing 15 ml of Amberlyst A26. The RU values of the solvent before and after the ion-exchange treatment were 82 .mu.gU/ml and 25 .mu.gU/ml respectively. EXAMPLE 3 One liter of solvent (comprising 200 ml of TBP and 800 ml of odourless kerosene) from the Recovery Line solvent extraction plant was washed repeatedly with 10% sulphuric acid in a series of box mixer-settlers as in Example 1, until free from uranium. The solvent was then passed at 150 ml/hr (1.0 Bv/hr) through an ion-exchange column containing 150 ml of Duolite A116, in the hydroxide form. The RU values of the solvent before and after the ion-exchange treatment were 275 .mu.gU/ml and 6 .mu.gU/ml respectively.