Abstract
Due to the continual depletion of resources and higher impurity levels found in copper concentrates worldwide, hydrometallurgical processes are being developed worldwide as a more suitable smelting process for high impurity concentrates. There are many cases in recent years where‘ medium temperature' leaching process is preferred because of the costs associated with the use of neutralizing reagents for the processing of the sulfuric acid by-product. By studying the properties of sulfur and iron during‘ medium temperature' leaching, it was observed that Fe (III) was effective for improving copper leaching by acting as an oxidation catalyst. Sulfur contained in chalcopyrite was melted and depressed the leaching reaction by covering remaining chalcopyrite. This effect was reduced with the formation of jarosite by the incorporation of sulfur and iron. During the initial stages of the reaction, sulfuric acid consumption preceded sulfuric acid formation as a by-product, since in the catalyst effects of Fe (III) promote leaching reaction of acid formation.
