Variables
Description
What is this formula?
The distribution ratio measures the equilibrium partitioning of a solute between the organic and aqueous phases during solvent extraction. It is one of the most important parameters for evaluating extraction performance.
When to use it
Use this formula when designing solvent extraction circuits, evaluating extractants, optimizing metal recovery, or analyzing laboratory extraction tests.
Example
A copper extraction test produces an organic-phase concentration of 12 g/L and an aqueous-phase concentration of 3 g/L.
Formula:
D = Co / Ca
Substitution:
D = 12 / 3
Result:
D = 4
Copper concentration in the organic phase is four times greater than in the aqueous phase.
Applications
- Copper SX/EW plants
- Hydrometallurgy
- Rare earth extraction
- Uranium recovery
- Chemical separations
Note
The distribution ratio depends on pH, temperature, extractant concentration, ionic strength, and phase composition. Higher D values generally indicate more favorable extraction, but economic and operational factors must also be considered.