7. Recent developments in copper hydrometallurgy

From the 1970s to the 1990s, there was growing interest in hydrometallurgy, although it would be very risky to think that it could replace pyrometallurgy, especially for sulfide ores. The main developments were the successful launch of large-scale SX-EW plants by major metallurgical companies, and the implementation of heap bioleaching for chalcocite-type copper sulfides.

Other recent processes include the following.

• Arbiter process

This ammoniacal leaching process (ammonia-ammonium sulfate solution), at atmospheric pressure, has been developed at Coloso by Minera Escondida. It can be applied to copper sulfide concentrates dominated by chalcocite and bornite, but leaching yields are only 40-50%, as the other associated sulfides (covellite) are not very soluble. Monovalent copper is...