University of Antofagasta Launches International Project to Develop Sulfide-Free Tailings Flotation Process

en.Wedoany.com Reported - A Chilean research team has launched a three-year international cooperation project aimed at addressing acid mine drainage from mining waste at its source. The project is led by Dr. Luis Cisternas, a researcher at the Advanced Mining Technology Center (AMTC) and scholar in the Department of Chemical Engineering and Mineral Processing at the Universidad de Antofagasta. Its core objective is to design flotation processes capable of producing sulfide-free tailings.

The project, titled "Enhancing Metal Recovery Through Multiscale Analysis: From Molecular Modeling to Process Optimization in Copper Operation" (ANID ECOS250037), has been funded under the 2025 ECOS-ANID Scientific Cooperation Program. The research team comprises researchers from the Universidad de Antofagasta, the L2CM laboratory at the Université de Lorraine in France, and the Universidad del Bío-Bío, with the Lorraine team led by Professor Michael Badawi.

Acid mine drainage is an acidic solution produced when sulfide minerals in mining waste come into contact with water and oxygen, potentially mobilizing metals and posing challenges to mine operations and environmental management of tailings facilities. The research team's proposed "Solid WithOut Sulfide" (S.O.S.) concept holds that tailings and other solid mining waste should be free of sulfide minerals. Dr. Cisternas stated that the project aims to generate knowledge through experimental research and molecular modeling to design processes that produce tailings without acid-generating elements, with the significance lying in eliminating the potential hazard of mining tailings at the source rather than treating it after the fact.

The project employs a multiscale research approach, combining experimental studies with molecular modeling tools, including ab initio calculations and density functional theory (DFT), as well as the design and optimization of flotation circuits. Researchers first understand the interactions of different minerals at the molecular scale and the conditions favoring their selective separation, then apply this knowledge to design more efficient flotation processes. Cisternas noted that molecular modeling helps understand scale effects in the separation of sulfide mineral mixtures, including differences in the ease of mineral separation and the conditions that promote selective separation, knowledge that can guide flotation circuit design.

This approach connects fundamental chemical phenomena with engineering decisions, enabling flotation circuit design to be based on a deep understanding of mineral separation mechanisms. The main expected outcome is to advance the design of flotation circuits capable of separating sulfide minerals, so that final tailings no longer have the potential to generate acid drainage. Cisternas explained that sulfide-free tailings are chemically stable, preventing the generation of acidic substances and the release of heavy metals associated with metal leaching.

The project is expected to reach Technology Readiness Level (TRL) 3-4 by the end of its three-year execution period, corresponding to laboratory validation, laying the groundwork for subsequent scale-up stages. In addition to scientific publications, the plan includes developing an open database of molecular models valuable to the international scientific community and proposing new approaches to flotation process design.

Other Chilean team members include Dr. Ricardo Jeldres Valenzuela and Dr. Yésica Botero from the Universidad de Antofagasta, Gonzalo Quezada Escalona from the Universidad del Bío-Bío, and doctoral students Andrés Canales Mahuzier and Grecia Villca Alarcón. Cisternas believes that if this research line is applied industrially, it would transform mining operations by addressing problems at the source of the process rather than managing them at the end of the production chain.