Hydroxyoxime is the main extractant in the copper solvent extraction industry. In the course of using the hydroxyoxime extractant it can degrade because of long-term contact with acid and other harmful ingredients. The degradation products consist of a series of substances, such as aldehyde, ketone, organic acids, amides and other organic debris. These degradation products accumulate in the organic and may affect the performance of the extractant. In this paper, the effect of degradation products on the performance of hydroxyoxime extractant was studied. Finally, various methods to eliminate the adverse effect of degradation products on extractants are discussed. The results showed that: (1) Degradation products such as aldehyde, ketone etc could change the extraction and stripping equilibrium, weaken the extraction ability and increase copper content in the raffinate. The higher content of degradation products in the organic phase, the more the extraction capacity decreased. (2) Degradation products could slow down the extraction kinetics. (3) The Cu/Fe selectivity of the extractant declines, which increases the iron concentration in the loaded organic. (4) Degradation products, especially surfactants, can prolong the phase separation time and accelerates the degradation of hydroxyoxime extractants.
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