Attrition grinding and leaching of enargite concentrate

Enargite Cu₃AsS₄ belongs to minerals with very low hydrometallurgical extroctibility of copper. An application pretreatment of enargite concentrate in acid solutions leads to simultaneous dissolution of copper and arsenic and the final leach liquors solutions have to be treated for the separation of both elements. The application of alkaline natrium sulphide solutions favours a selective leaching of arsenic and the copper forms solid residues suitable for pyrometallurgical treatment. The experiments have shown that more than 90 % of arsenic can be extracted from enargite by atmospheric alkaline leaching at 90 °C. An applied mechanical activation enhances the rate of arsenic extraction.