Design of a Thorium Extraction Process from Monazite Sand; The Environmental, Humanitarian, and Political Controversies of Exporting Our Pollution: Analysis of Global Impacts of Rare Earth Metal Technologies versus the Impacts on their Local Mining Communities

Finding a sustainable way to support our current standard of living is the crisis that our society will have to face in the coming decades. Emission free energy generation will be required to create a greener world and nuclear power will play a role in supplementing renewable generation. However, the current nuclear infrastructure is reaching the end of its lifetime. Novel nuclear technologies such as thorium reactors are therefore posed to become the next generation of nuclear power. Like any energy generation, thorium has raw material that must be processed into a final product in an economic way. Nevertheless, economic cannot be the only consideration in a more sustainable world. Raw materials for a process can come from all over the world and different part of the world produce in different ways. For example, the rare earth metals often found alongside thorium minerals are essential to many modern technologies but come from damaging mining operations in developing regions. The process of turning raw materials into modern innovations is complicated and explored in different ways in my thesis.

The technical portion of my thesis outlines a process for creating enough thorium oxide to sustain a sizable nuclear energy program on the east coast of the United States. My teams work develops a novel continuous process for thorium oxide formation that is safer than previous batch processes. Additionally, it shows that the process is economically viable assuming thorium fuel sees use comparable to that of uranium. The process begins with monazite ore being leached with sulfuric acid, the resulting solution being filtered, and then being separated based on pH. Further separations occur through two phase extraction after the addition of nitric acid to the system. Another separation occurs based on pH before being calcined under high heat in a rotary kiln. The plant itself would be relatively small but with 24-hour operation, would require about 200 employees for operation year-round. Annual revenue is estimated at about 44 million and annual costs are about 30 million. Over the 14-year lifetime of the project, economic analysis indicated a total profit of 34 million dollars.

The STS portion of my thesis focuses on a budding crisis in the rare earth mining industry. Rare earth elements are essential to many modern technologies such as wind turbines, batteries for portable electronics, and electric vehicles but an increasing demand is putting a burden on mining communities in developing regions of the world. Mines in the U.S. and Australia have shut down for environmental reasons and unregulated mines largely under Chinese influence maintain a competitive advantage as a direct result of their unsustainable practices. My research looks at this issue through the lens of Latour’s cartography of controversies as interpreted by Venturini. Through this research method, sources were collected to represent the views and effects on different groups in controversies of environmental, humanitarian, and political dimensions. Ultimately, the contributions of this research are a series of observations of these controversies. The key observation found was that solutions to this crisis are not clear in how they would actually be implemented. An approach to resolutions will require compromises with several important actors. Sustainable, novel technologies have a variety of challenges to overcome in our fast-moving world. New innovations must be physically viable, financially competitive with traditional products, and actually live up to their promise of sustainability. The technical side of my project makes contributions that would help encourage the usage of monazite ore for thorium and its rare earth metals but the STS side shows where difficulties still arise. Monazite can theoretically be mined in a sustainable way but the practicality of ensuring green practice becomes more difficult. Economics of our process are profitable but still sensitive to higher costs that would make things much less appealing. If raw material costs were to double or triple, the project would need government support to break even. Both sides of my thesis help inform further study on this topic that will be necessary as green innovation is further explored in our society.

School of Engineering and Applied Science
Bachelor of Science in Chemical Engineering
Technical Advisor: Eric Anderson
STS Advisor: Kathryn Neeley
Technical Team Members: Sam Ong, Peter Sepulveda, Anna Winter, Karl Westendorff