Qiu Zhong Wei Projects 2024

Mined and crushed ores contain a range of minerals with diverse chemistry and release a variety of species into water used in grinding, leaching, and other operations. This creates an aqueous phase commonly referred to as “mine waters” that contains a complex mixture of metallic and non-metallic species in varying concentrations. Such mine waters often contain concentrations of hazardous and toxic chemical species that exceed the limits required for safe recycling or release, posing environmental hazards for surrounding areas while increasing the cost of mining operations. Thus, efficient and cost-effective methods for mine water remediation are vitally important to making mining more sustainable. Herein, we propose to develop an efficient and inexpensive electrochemical process for the removal of a wide range of harmful dissolved species from large volumes of mine waters. Our multi-disciplinary approach will rely on collective expertise in fluid dynamics, colloidal science and surface chemistry, and electrochemical engineering to carry out proof-of-principle measurements of an electrochemical system. This device will utilize pH gradients and bubbles generated by electrochemical reactions to facilitate the efficient and selective separation of dissolved metals from mine waters. This work will bring together researchers at various career stages with the aims of establishing the engineering fundamentals behind the proposed process and positioning our team for follow-on funding by industry and government sponsors.

We have discovered that, in the presence of a mild-to-strong H2SO4 solution, we can generate H2O2 (aq) with an electro-Fenton-like process in the presence of Fe2+ ions and other battery-relevant transition metals without destroying the reactor components and dissolve refractory species of choice (e.g., battery cathodes and ores). During my leave in AY 21/22, I demonstrated a symbiotic effect when FeSO4 (aq) and H2SO4 (aq) are used as an electrolyte to produce H2 (g) and O2 (g), and a patent is pending on this benefit. Engineered materials, from steel to semiconductors to battery active components, begin with either minerals extracted from the Earth or recycled inputs from end-of-life (EOL) devices. Both classes of input material must be separated and purified to standards for the given application. Structural metals generally require less than 100 PPM of unintended dopants, and semiconductor and battery materials require under 1 PPM of labile impurities. Mineral extraction and recycling processes have evolved over millennia to achieve these goals, and the convergence of climate, societal, and economic concerns now requires us to significantly reduce the environmental impact of extraction and recycling while simultaneously reducing costs.

There is substantial recent interest in ammonia (NH3) as a long-duration energy storage medium to promote increased electricity decarbonization. However, significant challenges remain in the generation of electricity/power from NH3 (once produced) given its low reactivity and propensity to generate nitrogen oxides (NOx) as a harmful by-product inside combustion engines. Interestingly, as part of the “thermal deNOx” process, NH3 has long been added to post-combustion gases to destroy NOx in a self-sustaining reactive process. That is, NH3 can exhibit opposite chemical properties during oxidation depending on the exact thermodynamic conditions—hinting at the possibility of a “Goldilocks” regime where combustion engines can generate power from NH3 in a manner that promotes both stable operation and minimal NOx. While computational design tools may provide a means of identifying such conditions, the accuracy of the chemical models for NH3 impedes their utility. The goal of this project is to (1) develop an accurate chemical model for NH3 combustion using a novel multiscale data-driven methodology developed in the PI’s group and (2) use this model to identify optimal operating regimes for renewable-NH3-powered combustion engines.

This proposal aims to address the negative environmental impact of cement production by exploring the use of carbon-storing calcium carbonate polymorphs – aragonite and vaterite – derived from CO2 mineralization as sustainable alternatives in construction, particularly for 3D concrete printing applications. The project will optimize the properties of aragonite to serve as a rheological modifier to enable 3D concrete printing while investigating vaterite's potential as a cement-free binder. The use of these polymorphs can introduce additional functionalities to cement composites, reduce material waste, and revolutionize the manufacturing of building materials. The proposed work includes rheological characterization, 3D printing tests, and performance testing, and material characterization of printed samples. The funding provided by the Qiu Zhong Wei program will support a postdoctoral researcher, a graduate research assistant (GRA), and an undergraduate researcher, which will promote multiple levels of mentoring, supervision, and advising. The project's findings will also serve as important preliminary results for future grants and supporting results for a full patent application.