Rare earths: the new frontier Chilean mining is exploring

Chile's mining industry is shifting focus toward rare earth elements, a group of 17 critical minerals essential for technologies such as electric vehicles, wind turbines, and high-value screens. This transition comes amid global demand for materials crucial to the energy transition and advanced manufacturing. Experts say previously discarded mine tailings, byproducts of mineral extraction, are now being reconsidered as potential secondary sources of these valuable resources. The country generates around 1.7 million tons of mining waste daily, with over 795 deposits holding more than 1 billion tons of material that could be re-evaluated using modern technology. According to Leticia Campos, an academic from the University of Atacama, tailings represent leftover material from the concentration process of minerals. Historically, these were considered waste after extracting copper and molybdenum, which were the main targets during the 20th century. Other elements found in tailings lacked commercial value or were not technically or economically feasible to recover at the time. However, the shift in global energy demands has changed this perspective. Rare earth elements, including neodymium, lanthanum, and dysprosium, are now in high demand due to their role in renewable energy systems and high-tech applications. The recovery of these materials from tailings is part of what is known as "secondary mining," aiming to extract value from already extracted resources once deemed waste. Rare earth elements are not only present in tailings but also in primary deposits, marking a new frontier for exploration. The interest in these minerals has taken on geopolitical significance, with Chile and the United States agreeing earlier this year to strengthen cooperation on critical minerals and rare earths, recognizing their importance for supply chain security and advanced technologies. Despite lacking a developed rare earth industry, Chile has projects aimed at exploring this area. One such project is Aclara, located in the Biobío region. Irene del Real, an academic from the Department of Mining Engineering at the Catholic University, notes that Aclara represents the first discovery of a primary rare earth deposit in the country. Located near the town of Penco, the site has undergone a lengthy approval process due to existing mining activity and population density in the area. In June, the project received its Environmental Classification Resolution (RCA), and it is currently progressing through obtaining sector-specific permits. A key feature of the deposit is its composition. Unlike traditional rare earth deposits associated with rock, the elements in Penco are contained in shallow surface clays, allowing for a different mining process compared to conventional methods. Víctor Pérez, an academic from the Faculty of Engineering and Sciences at the Adolfo Ibáñez University, highlights the unique nature of the Penco deposit. In clay, rare earth elements are absorbed on the surface, making them accessible through ion exchange processes that can occur at ambient temperatures. This contrasts sharply with hard rock deposits, which require blasting and grinding, making the process in Penco simpler and less resource-intensive. The implications of this discovery extend beyond technical feasibility. It signals a strategic move by Chile to diversify its mineral exports and reduce reliance on traditional commodities such as copper. With growing international pressure to secure stable supplies of critical minerals, Chile’s efforts in developing its rare earth sector could position it as a key player in the global market. The success of Aclara will depend on securing all necessary permits and demonstrating economic viability. If successful, it could pave the way for further exploration and investment in rare earth deposits across the country. The project’s approach to utilizing surface clays instead of traditional hard rock mining offers a potentially more sustainable model for future operations.