Sustainable Production of Rare Earth Elements from Mine Waste and Geoethics

Abstract

The vulnerability of the rare earth element (REE) supply in a global context of increasing demands entails important economic and political issues, and has encouraged several countries to develop their own REE production projects. This study comparatively evaluated the production of REEs from primary and secondary resources in terms of their sustainability and contribution to the achievement of the Geoethics concept as responsibility towards oneself, colleagues, society, and the Earth system. Twelve categories of potential environmental and social impacts were selected: human health toxicity, global warming or climate change, terrestrial and aquatic eutrophication, acidification potential, particulate matter, resource depletion, water consumption, fresh water ecotoxicity, ionizing radiation, fossil fuel consumption, and ozone depletion. The results showed that the environmental impact of REE production from secondary sources is much lower relative to primary sources. A comparison of conventional and non-conventional REE resources showed that significant impact categories were related to particulate matter formation, abiotic resource depletion, and fossil fuel depletion, which could result from avoiding the tailings disposal before reuse. Based on these findings, governments and stakeholders should be encouraged to increase the recycling of secondary REE sources with Geoethics in mind, in order to balance the high demand of REEs while minimizing the overexploitation of non-renewable resources.

Remining for Renewable Energy Metals: A Review of Characterization Needs, Resource Estimates, and Potential Environmental Effects

“…For example, while many mines collect continuous tailings data on bulk chemistry (i.e., total metal content), density, and particle size distribution, details on mineralogy, particle microstructure, and weathering effects are rarely monitored [22]. Certain mine wastes may be radioactive, such as those from phosphate wastes that contain monazite, an REE phosphate mineral [23], and estimates of radioactivity will be needed. A generalized flow diagram for characterizing and managing tailings for remining is shown in Figure 1.…”

Past, Present, and Future of Copper Mine Tailings Governance in Chile (1905–2022): A Review in One of the Leading Mining Countries in the World

“…Traditionally, due to experiences that happened throughout the world, it is known that mining is responsible for adverse effects that cause: (i) environmental damage, (ii) health problems, (iii) forced population displacement, (iv) increase in social inequality and (v) corruption, etc. [ 69 ]. In addition, considering the experiences of mining projects in China, the production of REE generates significant social and environmental impacts due to the use of strong and corrosive chemicals, and also due to the generation of radioactive co-products, such as uranium (U) and thorium (Th) [ 69 ].…”

“…[ 69 ]. In addition, considering the experiences of mining projects in China, the production of REE generates significant social and environmental impacts due to the use of strong and corrosive chemicals, and also due to the generation of radioactive co-products, such as uranium (U) and thorium (Th) [ 69 ]. However, if a comprehensive governance strategy is applied, managing the activity responsibly, the mining industry can generate positive social and economic benefits, such as job creation, better education, investment, innovation, and improvement of infrastructure [ 69 ].…”