Liquid-liquid extraction process

In a liquid-liquid two-phase extraction process including the steps of

• introducing into an intermediate stage of a multistage extraction apparatus a feed solution comprised of an organic solvent and one or more valuable material to be recovered by extraction, which feed solution contributes to an organic phase of the two-phase extraction process and which multistage extraction apparatus has a first end and a second end;
• introducing into the first end of the multistage extraction apparatus an organic extractant comprised of an organic solvent, which organic extractant flows through the multistage extraction apparatus in a first direction and contributes to the organic phase;
• introducing into the second end of the multistage extraction apparatus an aqueous extractant comprised of water, which aqueous extractant flows through the multistage extraction apparatus in a second direction, which second direction is countercurrent to the first direction, and contributes to an aqueous phase of the two-phase extraction process,
• contacting the feed solution and the aqueous extractant to transfer by extraction the one or more valuable material from the feed solution into the aqueous extractant to provide a charged aqueous phase,
• contacting the charged aqueous phase and the organic extractant to transfer by extraction one of said one or more valuable material from the charged aqueous phase to provide a washed organic phase, the improvement comprising:
• dividing the aqueous extractant into at least two aqueous extractant streams prior to introducing the aqueous extractant into the multistage extraction apparatus;
• and
• introducing each of the at least two aqueous extractant streams into the multistage extraction apparatus at different stages, which different stages are both ahead, with respect to the second direction, of the intermediate stage at which the feed solution is introduced.

In a liquid-liquid two-phase extraction process including the steps of

• introducing into an intermediate stage of a multistage extraction apparatus a feed solution comprised of water and one or more actinide element including at least uranium to be recovered by extraction, which feed solution contributes to an aqueous phase of the two-phase extraction process and which multistage extraction apparatus has a first end and a second end;
• introducing into the first end of the multistage extraction apparatus an organic extractant comprised of an organic solvent and tributylphosphate, which organic extractant flows though the multistage extraction apparatus in a first direction and contributes to an organic phase of the two-phase extraction process;
• contacting the feed solution and the organic extractant to transfer by extraction the one or more actinide element from the feed solution into the organic extractant to provide a charged organic phase;
• introducing into the second end of the multistage extraction apparatus at least one aqueous extractant comprised of water and nitric acid for washing the charged organic phase to provide a washed organic phase comprised of uranium but substantially free of other actinide elements, which at least one aqueous extractant flows through the multistate extraction apparatus in a second direction, which second direction is countercurrent to the first direction, and contributes to the aqueous phase, the improvement comprising:
• dividing the organic extractant into at least two organic extractant streams prior to introducing the organic extractant into the multistage extraction apparatus;
• and
• introducing each of the at least two organic extractant streams into the multistage extraction apparatus at different stages, which different stages are both ahead of, with respect to the first direction, the intermediate stage at which the feed solution is introduced.

In a liquid-liquid two-phase extraction process including the steps of

• introducing into an intermediate stage of a multistage extraction apparatus a feed solution comprised of an organic solvent and one or more actinide element including at least uranium and plutonium to be recovered by extraction, which feed solution contributes to an organic phase of the two-phase extraction process and which multistage extraction apparatus has a first end and a second end;
• introducing into the first end of the multistage extraction apparatus an organic extractant comprised of an organic solvent and tributylphosphate, which organic extractant flows through the multistage extraction apparatus in a first direction and contributes to the organic phase;
• introducing into the second end of the multistage extraction apparatus an aqueous extractant comprised of water and nitric acid, which aqueous extractant flows through the multistage extraction apparatus in a second direction, which second direction is countercurrent to the first direction, and contributes to an aqueous phase of the two-phase extraction process,
• contacting the feed solution and the aqueous extractant to transfer by extraction the one or more actinide element from the feed solution into the aqueous extractant to provide a charged aqueous phase,
• contacting the charged aqueous phase and the organic extractant to transfer by extraction uranium from the charged aqueous phase to provide a washed organic phase comprised of uranium but substantially free of other actinide elements, the improvement comprising:
• dividing the aqueous extractant into at least two aqueous extractant streams prior to introducing the aqueous extractant into the multistage extraction apparatus;
• and
• introducing each of the at least two aqueous extractant streams into the multistage extraction apparatus at different stages, which different stages are both ahead, with respect to the second direction, of the intermediate stage at which the feed solution is introduced.