Xueya Lu

My research project focuses on carbon sequestration using mine tailing materials. Through characterization, identification and evaluation chemical components that offset anthropogenic greenhouse gas production. To be more specific, carbon is captured from air or from industrial point sources and is mineralized in carbonate minerals that generate additional co-benefits to mine operations, including dust mitigation, tailings stabilization, and toxic metal encapsulation

Ultramafic mine tailings represent a considerable opportunity to sequester carbon dioxide from the atmosphere and could enable mining with net negative greenhouse gas emissions. In this process, carbon is captured from the air or from industrial point sources and is mineralized in carbonate minerals that generate additional co-benefits to mine operations, including dust mitigation, tailings stabilization, and toxic metal encapsulation. The cost by which this process can be deployed is expected to correlate with the reactivity of magnesium in tailings to CO2-bearing solutions. We focus on loosely bound magnesium, termed labile Mg, that is inexpensive and can be readily leached at room temperature. Flow-through time-resolved analysis (FT-TRA) dissolution experiments are used to quantify the labile Mg content of tailings as a measure of reactivity, and thus CO2 sequestration potential. Experimental data show that labile Mg content can vary by orders of magnitude between and within individual mineral deposits. What remains unclear, is if labile Mg content of individual samples also varies with the dissolution environment, which will depend on the CCUS approach. We very acid type and strength to evaluate the uniqueness of labile Mg contents for single mine tailings samples. Future works involve the development of models with the predictive capability that is cost-saving by performing limited dissolution tests on tailings samples for quantifying CO2 sequestration potential of the targeted mine deposits. Ultimately, these results will help to establish a foundation upon which to develop characterization protocols to assist in the development of CCUS at mine sites around the world.