To ensure a secure domestic supply of critical minerals, FECM’s Critical Mineral Sustainability Program accelerates production from unconventional and secondary sources. These include legacy byproducts from fossil energy use (e.g., coal ash and refuse), acid mine drainage, and produced waters from natural gas and oil operations. The program’s research, development, demonstration, and deployment (RDD&D) focuses on the development of novel and advanced technologies to enable cost effective and sustainable extraction of rare earth elements and other critical minerals from unconventional and secondary sources. The RDD&D efforts advance environmentally benign and economically efficient processing, including extraction, purification, reduction, refining, and alloying techniques and technologies. These processes produce high-purity critical minerals, including rare earth metals, and facilitate manufacturing of high value carbon products. The final step is to scale up these technologies to small- and large-scale pilots and larger field demonstrations.