Patent ID: 7695625

Claim:
A method for scrubbing aqueous entrainment, or impurities, or both from an organic extraction solution that: is obtained from a liquid-liquid extraction during hydrometallurgical recovery of metals; contains a valuable metal or substance that has been introduced into it during the liquid-liquid extraction; is slightly soluble in aqueous solutions; the method comprising: introducing the organic extraction solution into a settling tank comprising: a front end; a rear end; and at least one vertically extending droplet coalescer extending across the settling tank at at least one point, the droplet coalescer comprising: a flow channel zone that is located in an upper section of the droplet coalescer, and comprising a plurality of overlapping flow channels inclined obliquely upwards in the direction of flow and having surfaces that are roughened, shaped to cause swirling, or both; a solid center portion; and a guide channel portion located in the lower section of the droplet coalescer, comprising a plurality of overlapping guide channels inclined obliquely downwards in the direction of flow; wherein the number of guide channels in the guide channel zone of the droplet coalescer is ⅙ to ⅓ of the number of flow channels in the flow channel zone of the droplet coalescer; flowing the organic solution from the front end of the settling tank toward the rear end of the settling tank, and through the flow channel zone; coalescing in the flow channel zone aqueous entrainment in the organic extraction solution into droplets sufficiently large to settle to the bottom of the settling tank to form a separated aqueous solution; flowing the separated aqueous solution through the guide channels in the lower section of the coalescer; and removing scrubbed organic extraction solution and separated aqueous solution from the settling tank in separate streams.