Earthworks, Transport and Environment (T&E), and Earthjustice released an independent peer-reviewed open-access report on remining published in Minerals that is considered one of the first and most comprehensive literature reviews on the issue.

“Remining” refers to the process of using mine waste as a source material to extract minerals or create other materials of economic value. As the demand for clean energy technologies increases, questions remain on sustainably securing the minerals needed to fuel the energy transition.

Remining has been researched for decades, but its potential to supplement virgin extraction is currently unknown. This review addresses the remining of tailings/waste rock, coal residues, and byproduct and primary production materials for renewable energy metals (e.g., Co, Ni, REEs, Mn, Li).

Geochemical characterization methods for estimating pollution potential must be supplemented with mineral liberation analysis and process testing to reliably estimate remining’s economic potential. National and regional remining characterization efforts currently exist in the U.S., Europe, Australia, and China but will take years to produce viable operations at scale.

Tailings hold the most promise due to their large amounts worldwide and the fact that they are already extracted and pre-processed, which reduces energy and water use. Of the processing approaches examined, bioleaching appears to offer the most benefits with the fewest potential downsides. The advantages and challenges of the processing methods and remining sources are presented. Best remining practices are urgently needed to improve resource estimates and avoid impacts such as the tailings dam failures that occurred at remining operations in Romania and South Africa.

Interest in remining is booming because it can increase domestic supply. If properly conducted, remining can also improve circularity and environmental conditions in areas affected by existing and legacy mining activity.

—Maest (2023)

Developed to help policy makers initiate discussions with impacted communities and Tribal governments, “Remining for the Energy Transition,” analyzes remining in the United States and the European Union (EU). Specifically, the policy brief—which is informed by the published report—identifies the capacity for generating energy transition minerals from waste deposits, expected benefits and dangers, and best practices that reinforce gains and mitigate risks.

The report shows prospects for remining minerals in the United States. But remining is mining, and current laws do not go far enough to stop dangerous mining practices.

—Aaron Mintzes, Senior Policy Counsel of Earthworks

Mintzes warned that before it can be regarded as a viable option, more research, better data, and strong regulations such as mine waste characterization, an overhaul of the 1872 mining law, and Free and Prior Informed Consent from Indigenous Peoples must be enforced to protect people, communities, and the environment.

Resources

• Maest, Ann S. (2023). “Remining for Renewable Energy Metals: A Review of Characterization Needs, Resource Estimates, and Potential Environmental Effects” Minerals 13, no. 11: 1454 doi: 10.3390/min13111454