The complete copper pressure leaching process concept includes pressure leaching in an autoclave to produce copper-containing pregnant leach solution. Leaching is followed by a neutralization step and then copper solvent extraction and electrowinning. Gold and silver can be recovered by adding a lime boil step before cyanide leaching.
The Copper Pressure Oxidation Plant is an Outotec proprietary technology for impure concentrate refining. The new process offers an effective way to dissolve concentrate, remove impurities, and recover copper as LME A-grade cathodes. In addition, the flowsheet can be modified to recover silver and gold. It is an easy-to-operate, self-optimizing plant that provides high availability and fast ramp-up to production.