2024 Theses Doctoral
Stepwise coprecipitation of energy-relevant critical elements integrated with carbon mineralization technology
The U.S. Department of Energy (DOE) emphasizes the importance of identifying secondary sources for energy-relevant critical elements, driven by the escalating demands of the high-tech industry and products. Elements such as Ni, Cu, and REEs, are crucial for the development of clean energy technologies such as solar panels, wind turbines, electric vehicles, and battery storage systems. As the global demands for these technologies grow in response to climate change and the push for sustainable energy solutions, securing a stable supply of critical elements becomes imperative. Secondary sources, including alkaline industrial waste, natural Magnesium-bearing minerals, and e-waste, offer a sustainable path forward. They not only help mitigate supply risks but also offer a potential source of Ca and Mg for carbon mineralization. The DOE's focus on secondary resources highlights the need to ensure the resilience of energy infrastructure and the transition towards a more sustainable and secure energy future.
Thus, this study embarks on a critical exploration of sustainable mining practices from secondary resources and investigates the novel method for energy-relevant critical elements recovery, and the application of carbon mineralization techniques for CO₂ sequestration. The research traverses a proposed stepwise coprecipitation process integrated with a carbon mineralization process in alkaline industrial waste (e.g., iron slag) and natural Magnesium-bearing minerals (e.g., Olivine). This research also delves into the use of a mild in-situ mechanical grinding method for Au, Ni, and Cu recovery from printed circuit boards (PCBs).
Further expanding on the theme of waste valorization, this study delves into the use of blast furnace slag (BFS) for ex-situ carbon mineralization, showcasing a stepwise pH swing-assisted hydrometallurgy process. This approach not only allows the recovery of REEs but also the storage of CO₂ by carbonation the Ca and Mg reach solution, illustrating the potential for industrial waste to mitigate climate change impacts and metal scarcity.
The coprecipitation process for the selective recovery of Ce from Fe solutions is explored. Through detailed characterizations by ICP, XRD, XPS, and SEM, this research reveals the underlying mechanisms of Ce recovery and proposes a weak acid dissolution process for its efficient extraction, emphasizing the role of chemical engineering in enhancing resource recovery.
In exploring the sustainable recovery of Ni and Mg from olivine minerals, the research highlights the connection between leaching kinetics, crystal phase and silicate structure by using XPS and XRD. The study showcases the feasibility of pH control and stepwise coprecipitation process techniques in optimizing the purity and crystallinity of magnesium carbonates, contributing to the broader goal of reducing environmental footprints and enhancing techno-economic feasibility.
This study also presents a mild mechanical grinding assisted method for the recovery of precious metals from printed circuit boards (PCBs). This investigation analyses the mechanical properties such as Young’s modulus, hardness, and surface roughness by using analytical techniques such as nanoindentation and AFM. This novel approach to precious metal recovery not only demonstrates a significant improvement in the efficiency of metal recovery but also contributes to the growing body of knowledge on sustainable e-waste recycling practices.
Subjects
Files
This item is currently under embargo. It will be available starting 2026-10-14.
More About This Work
- Academic Units
- Earth and Environmental Engineering
- Thesis Advisors
- Park, Ah-Hyung
- Degree
- Ph.D., Columbia University
- Published Here
- October 23, 2024