Copper recovery using leach/solvent extraction
leaching of highgrade copper oxide ore followed by EW of copper from the leach solution, produced low quality copper cathode at relatively high cost. In 1968 the tonnage of high grade oxide ores was decreasing and vat leaching was on the decline. The second process, heap and dump leaching of lowgrade oxide and/or sulphide ore followed by precipitation of low quality copper from the leach