Anion Exchange Behavior of Copper and Some Metallic Impurities in HCl Solutions

In order to lay a foundation of a potentially efficient separation procedure for copper in hydrochloric acid solutions, we have investigated the adsorption of copper and several characteristic impurity elements on a strongly basic anion exchange resin in a wide range of HCl concentration. Further experiments were carried out to determine the HCl concentrations and activities in the resin phase. The initial increase of the obtained equilibrium distribution coefficients with increasing HCl concentration indicates the formation of negatively charged complex ions. This tendency of the adsorbability functions is generally reversed at higher HCl concentrations. Analysis of the ion exchange equilibrium based on the obtained adsorbability and activity functions in the higher HCl range provided an interpretation of anion exchange behavior and pointed out the probable average charges carried by the stable, exchangeable species. Possible associations of the examined ions have also been taken into consideration. Comparison of the adsorbability functions showed sufficiently large differences to allow effective purification of initially monovalent copper in chloride solutions, and the obtained average charge of the Cu(I) species can be applied to loading considerations.