An investigation on the extraction of copper from Küre/Kastamonu pryitic copper ore with nitrogen species catalyzed oxidative pressure leaching

Copper is generally recovered from complex copper ores by pyrometallurgical methods such as smelting. However, concerns over air pollution have made governments tighten their regulations regarding the emission of sulfur dioxide. Therefore, hydrometallurgical processing of copper ores has become an increasingly important process due to its environmentally benign characteristics, lower capital cost and ease of operation. In this study, the dissolution kinetics of bulk flotation chalcopyrite concentrate obtained from Küre Copper Concentrator Plant-Eti Bakır Corporation was investigated in sulphuric acid media at high pressure and under the effect of oxy-nitrogen species. It was determined that chalcopyrite concentrate contains 11.21 percent copper, 5.10 percent zinc, 32.36 percent iron and 36.15 percent sulphur as major components. Mineralogical analyses of the sample contain mainly chalcopyrite with sphalerite, pyrite and small amounts of covellite, chalcocite, bornite. For dissolution of copper, the optimum pressure leaching conditions were determined by varying particle size, temperature, sodium nitrite concentration, the amount of sodium lignosulfonate, sulfuric acid concentration, solid-liquid ratio, total pressure, sodium nitrate concentration and stirring speed. The yield of copper recovery was found as approximately 95 percent at the optimum conditions.