Overcoming Passivation: Accelerating Copper Leaching from Low-Grade Ores and Mine Waste with AlCl3
摘要
The rising demandDemand for copperCopper in a low-carbonCarbon future necessitates efficient extractionExtraction methods. This study introduces a novel approach to copper extractionCopper extraction using AlCl3 as a lixiviant. AlCl3, a cost-effective reagent with diverse industrial applications, promotes direct and indirect dissolutionDissolution mechanisms. The direct mechanism involves the formationFormation of Al-rich precipitates, which facilitate the release of Fe3⁺ ions, a key oxidant for copperCopper dissolutionDissolution. Additionally, AlCl3 can catalyze the transformation of chalcopyriteChalcopyrite into more soluble secondary copperCopper phases, such as covellite-like, via a Lewis acid mechanism. In contrast to traditional lixiviants, AlCl3-based systems can limit the formationFormation of passivating secondary mineralsSecondary minerals like jarositeJarosite. The formationFormation of Al-rich precipitates, which are more soluble and porous, can hinder the formationFormation of jarositeJarosite and maintain a higher concentration of Fe3⁺ in solution. This study provides valuable insights into the potential of AlCl3-based leachingLeaching for efficient copper extractionCopper extraction from low-gradeGrade ores and mineMine waste as well as offers a promising alternative to conventional methods.