How does solvent extraction separate uranium from vanadium in carnotite processing?

In the processing of carnotite ore, solvent extraction is used to selectively separate uranium and vanadium from a sulfuric acid leachate. After the ore is leached and solids are removed, the resulting solution is fed into a solvent extraction circuit.1

The separation process works as follows:

• Uranium Extraction: The leachate is contacted with an organic solvent—typically composed of 2.5 percent amine, 2.5 percent isodecanol, and 95 percent kerosene. The uranium is selectively transferred into this organic phase.1
• Raffinate Formation: The vanadium does not transfer into the organic solvent and remains in the aqueous solution, which is known as the raffinate.21
• Vanadium Recovery: This vanadium-rich raffinate is then fed into a second solvent extraction circuit, where the vanadium is extracted into a separate organic phase, stripped using a 10 percent soda ash solution, and subsequently precipitated.1

This multistage approach allows for the efficient recovery of both metals as distinct products.1