One of the by-products of KCM’s refining operations at Nkana is anode slimes. This material is exported under long term contracts to third parties for the recovery of the contained minerals.

During the electrolysis process pure copper is deposited on cathode plates and impurities which are soluble fall to the bottom of the cell as anode slimes or sludge. Precious metals (Ag, Pt, Pd), can be extracted from the anode sludge created by the electro-refining process. Copper concentrates can also contain precious metals like gold and silver.