Copper is the most noble of the first row transition metals and occurs in small deposits in several countries. Ores of copper include chalcanthite (CuSo4.5H2O), atacamite (Cu2Cl(OH3)), cuprite (Cu_2O), copper glance (Cu2S) and malachite (Cu2(OH2)CO3). However, 80% of the world copper production comes from the ore of chalcopyrite (CuFeS2). The extraction of copper from chalcopyrite involves partial roasting, removal of iron and self-reduction.
In self-reduction, the reducing species is