Gary A. Kordosky

Copper solvent extraction: The state of the art

Copper recovery by solvent extraction has progressed from a technology with limited application for copper recovery from dilute sulfuric acid leach solution to a technology with broad application for copper recovery from a variety of leach solutions. Reagent improvements have led the way, but they have been accompanied by innovations in leaching and improvements in electrowinning. Of particular interest is the fact that specialized reagents have been developed to meet the specific needs of certain leaching solutions.

Gold solvent extraction from typical cyanide leach solutions

Abstract The guanidine ion pairing functionality, which exists in its protonated form at pH 13.5. Continuous solvent extraction circuits, run in the laboratory and in the field, suggest that leach-SX-EW technology, so successfully applied in the copper industry, is technically feasible for gold.

Equilibrium Copper Strip Points as a Function of Temperature and Other Operating Parameters: Implications for Commercial Copper Solvent Extraction Plants

Abstract The development of pressure and bioleaching processes for high grade copper ores and concentrates will result in copper solvent extraction plants treating solutions with high copper and acid concentrations at temperatures up to 45°C and these copper solvent extraction plants will run with reagent concentrations up to 40 vol.%. There is also a trend to use copper stripping solutions with less acid than typically used in recent years. Cognis has developed a model that accurately predicts the copper strip point for virtually any copper solvent extraction reagent or combination of reagents under a wide variety of conditions. The equilibrium strip points for several well known commercial copper solvent extraction reagents are given as a function of reagent concentration, the copper and acid concentration of the strip aqueous, and the temperature. It is shown that the equilibrium strip point is not a straight line function of reagent concentration and that the equilibrium strip point increases with an increase in temperature. Copper extraction also increases as the temperature increases.