Abstract
The materials that make clean energy possible are among the most politically contested resources on Earth. My capstone project addresses the technical side of this challenge through the design of a process to extract and separate rare earth elements (REEs) from ore, in which the ultimate goal is to produce a high-purity praseodymium-neodymium (Pr–Nd) oxide product. This project is motivated by current U.S. supply chain vulnerabilities that stem from a reliance on Chinese processing and refining capacity. My STS research paper examines the other side of this issue, analyzing how the U.S. frames critical mineral supply as a matter of national security and how that framing is more political than materially achievable. Not only do these two projects share subject matter, they actually stress-test each other. The capstone’s economic and technical limitations directly reinforce the STS paper’s argument that domestic independence claims consistently outrun the realities of mineral production.
The capstone project addresses the problem of limited and geopolitically concentrated REE supply by proposing a process to produce approximately 3.73 million kg per year of high-purity Pr–Nd oxide from bastnäsite-rich ore sourced from Mountain Pass, California. The design integrates beneficiation, calcination and leaching, and solvent extraction for initial separation, followed by cerium removal and staged ion exchange to isolate and recover the Pr–Nd product stream. This sequence reflects established industrial methods and incorporates design choices to further improve recovery and purity. The methodology integrates mass balance calculations, equipment sizing, and process flow development to create a scalable system grounded in chemical engineering principles.
The final design demonstrates that producing Pr–Nd oxide through this process is technically feasible, yet reveals significant limitations. The plant’s capital and operating costs substantially exceed projected revenue from the single product stream. While expanding the process to monetize additional rare earth products would improve financial performance, the resulting internal rate of return remains below acceptable thresholds for high-risk industrial investment. These findings reinforce that even well-designed domestic processes face practical limits when scaled, exposing the trade-offs between economic, environmental, and security priorities.
The STS research paper asks: how does the U.S. pursuit of critical mineral independence reproduce the historically flawed logic of energy independence, and what sociotechnical consequences does this repetition produce? This question is significant because it challenges the assumption that increasing domestic production leads to greater security. The study uses a qualitative, discourse-oriented policy analysis grounded in the framework of techno-nationalism, which links technological capacity, national security, and state power, to examine how policy priorities and technological development are co-produced. Primary sources include executive orders, federal policy documents, and historical energy policy, which together reveal how narratives of independence are constructed and sustained across administrations.
The analysis finds that mineral independence operates more as a political narrative than an achievable goal. Despite structural dependence on global supply chains and limited domestic reserves, policy continues to frame domestic extraction as a path to autonomy. In reality, technological innovation often shifts social and environmental burdens and introduces new inefficiencies rather than eliminating dependence. Together, these projects show that rare earth extraction is a sociotechnical system in which engineering design, environmental trade-offs, and geopolitical strategy are deeply intertwined, and that addressing these challenges requires both technical and critical perspectives.
