Studies into copper extraction by Acorga M5774 from heap leaching solutions of the Sayak deposit

The process of extraction/re-extraction of copper from heap leaching solutions using the Acorga M5774 Solvay extractant (Sytec, Belgium/USA) representing a modified aldoxime (5-nonylsalicylaldoxime) was studied. This extractant is characterized by a high effectiveness and a large selectivity of copper to iron, thus enabling a more rapid phase separation. During experiments, a pregnant leach solution obtained after the percolation leaching of the Sayak deposite ore (Republic of Kazakhstan) was used, g/dm3: H2SO4 – 11.67, Сu – 2.44, Fe – 2.613, Al – 0.345, Si – 0.127, Zn – 0.05, рН = 1.85. The main parameters and effectiveness of the extractant were studied by plotting extraction and re-extraction isotherms, as well as by simulating the closed cycle processing sequence and determining the level of copper extraction at the liquid extraction stage. The extraction/re-extraction of copper from pregnant leach solutions was studied. An aliphatic product of Elixore 205 (Total, France) was used as an extractant diluent, with the amount in the organic phase equal to 90%. Based on the conducted studies, extraction and re-extraction isotherms were plotted. In the liquid extraction process, simulated using the obtained isotherms, the extraction of copper comprised 96.18% (at an organic/aqueous phase ratio of 1.1) with a reagent saturation of 79%. The dependence of iron transfer from the organic phase on the saturation of organic phase with copper was obtained. Thus, the performed studies confirmed the effectiveness of the Acorga M5774 extractant for the purposes of extracting copper from pregnant leach solutions obtained during heap leaching of the Sayak deposit ore.