ekstraktionskredsløb

An ekstraktionskredsløb, or extraction circuit, is a fundamental concept in chemical engineering and analytical chemistry used to separate components of a mixture based on their differing solubilities in two immiscible solvents. This process is commonly employed in liquid-liquid extraction, where one solvent is used to selectively remove a desired solute from another solvent. The term "kredsløb" (circuit) implies a continuous or repeating process, although the fundamental principle can be applied in batch operations as well.

The core idea behind an ekstraktionskredsløb is the distribution of a solute between two phases. When two immiscible liquids are brought into contact with a solute present in one of them, the solute will partition itself between the two liquid phases according to its relative solubility. This partitioning is governed by the distribution coefficient, which is the ratio of the solute's concentration in the two phases at equilibrium. A favorable distribution coefficient allows for efficient extraction of the solute from the initial solvent into the extracting solvent.

In a continuous extraction circuit, the two immiscible phases are brought into contact, and the solute is transferred from one phase to the other. The phases are then separated, and the extracting solvent, now enriched with the solute, is processed further. The original solvent, depleted of the solute, is also sent for further treatment or recycled. Various equipment designs, such as mixer-settlers, extraction columns (e.g., packed columns, sieve tray columns, pulsed columns), and centrifugal extractors, are used to facilitate efficient contact and separation of the liquid phases in an industrial setting, forming a continuous operational circuit.