Stripping
also known as back-extraction · backwashing
Stripping, also called back-extraction, reverses the extraction reaction. The loaded organic is contacted with an aqueous strip solution whose chemistry — low pH for acidic extractants, or a strong acid for amine systems — pushes the metal back into the aqueous phase. The strip liquor leaves concentrated and pure, and the regenerated organic returns to extraction.
Why it matters in practice
Stripping is where the concentration factor of the whole circuit is actually realised. If stripping is incomplete, the returning organic carries residual metal, which steadily poisons extraction performance and inflates the organic inventory in circulation.
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Equipment referenced in this entry
Related terms
Reference entry GL-STRIPPING. Definitions on this page describe engineering practice in hydrometallurgical process design; they are not a substitute for test work on your own material.