Abstract: This invention relates to a process whereby recovery of copper from copper ores using leaching and ion exchange techniques can be increased. The process generally comprises leaching to obtain a pregnant leach liquor, washing ore residues with an extra quantity of water to obtain extra dissolved copper values, recovering said copper values, combining the extra wash water with the pregnant leach liquor, extracting copper values from the total leach liquor by ion exchange techniques to yield a raffinate which still contains some copper values, and cycling part of the raffinate through a low pH ion exchange circuit to lower the copper values remaining in the raffinate to about 0.01 to 0.02 grams per liter or less before disposal.

Abstract: This invention relates to a process whereby recovery of copper from copper ores using leaching and solvent extraction techniques can be increased. The process generally comprises leaching to obtain a pregnant leach liquor, washing ore residues with an extra quantity of water to obtain extra dissolved copper values, recovering said copper values, combining the extra wash water with the pregnant leach liquor, extracting copper values from the total leach liquor to yield a raffinate which still contains some copper values, and cycling part of the raffinate through a low pH extraction circuit to lower the copper values remaining in the raffinate to about 0.01 to 0.02 grams per liter or less before disposal.