Patent ID: 7704398

Claim:
A method for the physical purification of an aqueous solution, obtained from a liquid-liquid extraction occurring during the hydrometallurgical recovery of metals, from droplets of organic extraction solution, comprising: introducing an aqueous solution containing droplets of organic extraction solution obtained from a liquid-liquid extraction occurring during the hydrometallurgical recovery of metals 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 least one point, comprising: a flow channel zone that is located in a lower section of the settling tank and comprising a plurality of flow channels inclined obliquely downwards in the direction of flow and wherein each flow channel comprises one or more surfaces that are roughened, shaped to cause swirling, or a combination of these; a solid center portion; and a guide channel portion located in an upper section of the settling tank and comprising a plurality of guide channels inclined obliquely upwards in the direction of flow and which comprise surfaces that are roughened, shaped to cause swirling, or a combination of these; and flowing the aqueous solution containing droplets of organic extraction solution through the flow channel zone; coalescing in the flow channel the droplets of organic extraction solution to a sufficient size that they rise toward an upper surface of the settling tank to form a separated organic extraction solution; flowing the separated organic extraction solution through the guide channels in the upper section of the droplet coalescer; and removing the separated aqueous solution and the separated organic extraction solution from the settling tank in separate streams.