Her presentation, titled «Preliminary Evaluation of Passivation Technology to Prevent Acid Mine Drainage in Copper Tailings,» is the result of a project involving, in addition to Marcela Calderón, researchers Dilan Campos Quiroz, David Rubinos, and Jacques Wiertz from SMI-ICE-Chile; Tamara Ortiz P and Sofia Leonor Paredes Guerra from the Universidad del Desarrollo; Javiera Gerding and Oscar Jerez from the Universidad de Concepción; and Almendra Nieto Torres, a student of Civil Engineering in Biotechnology at the University of Chile.
Acid mine drainage (AMD), generated in the tailings of mining operations, is one of the greatest environmental and economic challenges facing the mining industry. The main cause of this problem is an iron-sulfur mineral called pyrite, which, when it comes into contact with water and oxygen—and sometimes bacteria—oxidizes and generates this acid drainage that contaminates surface and groundwater, seriously endangering crops, flora, fauna, and even human health.
“Most current solutions are reactive,” explains Marcela Calderón. “They focus on post-treatment after the formation of acid mine drainage and are very expensive and have limited long-term effectiveness.
“The focus of our work is prevention,” he says. “Passivation seeks to prevent this acid drainage at its source by coating the surface with sulfides, a process that inhibits oxidation and reduces the release of acids and metals.
“Early results indicate that laboratory-scale passivation technology has promising performance in terms of its ability to microencapsulate pyrite and reduce pH in tailings, opening the potential for long-term risk and cost reduction. These are preliminary but encouraging results.”
Marcela Calderón points out that the next steps are to scale up this work with field testing and validation to evaluate the stability of the sulfide coatings in the face of environmental changes.
This research is part of a project under Corfo’s Crea y Valida Program to promote innovation and is also supported by the Center for Research in Technologies for Society (C+) of the Faculty of Engineering of the University of Concepción and the Institute of Applied Economic Geology of the University of Concepción.
