A State-of-the-Art Discussion on the Solvent Extraction Reagents Used for the Recovery of Copper From Dilute Sulfuric Acid Leach Solutions

The recovery of Cu from dilute sulfuric acid leach solutions has been a commercial reality since 1968, and since then the technology has gained worldwide acceptance. Only one chelating functionality, the hydroxy oxime group, has been used commercially for this task. There are, however, two distinct classes of extractants based on the hydroxy oxime group: the salicylaldoximes, which are very strong Cu extractants and the ketoximes, which are moderate Cu extractants. A third class of extractants combines a ketoxime with a salicylaldoxime in about a 1:1 mole ratio and results in some surprising advantages. Each reagent class is discussed, showing its advantages and disadvantages and two new reagents, LIX 84 and LIX 984 are introduced, showing their behavior with respect to Cu extraction, and discussing where they may be used to advantage. 18 ref.--AA