Process and apparatus for extracting metals from waste waters

摘要

In the liquid-liquid extraction of metals from industrial waste waters (effluent) by means of a cationic extractant, the extractant, contained in an organic solvent such as kerosene, is mixed with the waste water to be extracted by means of a mixer pump (1) to give a product stream and passed through a reaction tube (7), the dimensions of which, matched to the size of the product stream, permit a sufficient reaction time. Baffles in the reaction tube ensure a continuous mixing of waste water and extractant. For a selective extraction, the pH is monitored at the outlet (6) of the mixer pump (1) and used for metering a substance serving to adjust the pH, which substance is likewise supplied to the mixer pump (1) via a pipe (5) provided with a metering element (18). The product stream is introduced into a vessel serving as separation stage via a coalescer (10) from the outlet of the reaction tube (7).