our research
There is a vital and pressing need to reduce greenhouse gas (GHG) emissions as the concentration of atmospheric carbon dioxide (CO₂) continues to rise and the impacts of climate change become more pronounced. Additionally, carbon pricing provides financial motivation for individuals, industries, and countries to curb GHG emissions. We conduct field studies and laboratory experiments supplemented with geochemical modelling to examine mineral-water-CO₂ interactions while seeking to address environmental issues from climate change to sustainable Earth resources. Our work has made significant advances for better understanding carbon cycling in the critical zone, microbial and enzyme-mediated carbonation, enhanced weathering and bioleaching, and mine waste carbonation at Earth’s surface conditions. We are carrying out many exciting projects and are aiming to launch several others in the next year. If you’re interested in joining the team, please email Dr. Power (ianpower@trentu.ca) about your research interests.
CO₂ sequestration within Mine wastes
The generation of mine wastes, including tailings, is increasing as demand for mineral resources grows and high-grade ore deposits become scarcer. Consequently, the mining industry faces the dual challenge of developing more secure and sustainable mine waste management practices while reducing greenhouse gas emissions. Alkaline mafic and ultramafic mine wastes contain Mg- and Ca-bearing minerals that can react spontaneously with atmospheric CO₂, storing carbon within stable carbonate minerals.
Our research investigates the rates and mechanisms of CO₂ sequestration within mine wastes and develops strategies to accelerate these naturally occurring reactions. Working with major mining companies, we combine laboratory experiments, field studies, and geochemical modelling to quantify carbon sequestration and investigate how mineralogy, water content, CO₂ supply, and mine waste management practices control carbonation rates. Ultimately, our goal is to integrate CO₂ mineralization into mine waste management, reducing net greenhouse gas emissions while providing additional environmental benefits.
Related publications include The mining industry’s role, Geochemical modelling of CO₂ removal in mine wastes, CO₂ mineralization of kimberlite residues, and CO₂ mineralization of brucite-bearing mine tailings.
The coarse residues and processing plant at the Venetia Diamond Mine, South Africa.
Kwon Rausis measuring CO2 fluxes for soils amended with wollastonite at the Trent Experimental Farm.
Enhanced rock weathering
Enhanced rock weathering (ERW) aims to accelerate the natural consumption of atmospheric CO₂ through mineral weathering, a process that has helped regulate Earth’s climate over geologic time. Pulverized silicate rocks and minerals, such as basalt, olivine, and wollastonite, can be applied to agricultural soils, forests, and other terrestrial environments, where their high surface areas accelerate weathering and CO₂ removal. Mine wastes and other finely ground rock materials may also provide abundant feedstocks for ERW while reducing the need for additional mining and processing.
A major challenge is determining how quickly these materials weather and accurately quantifying the resulting CO₂ removal. Our research combines laboratory experiments with field trials to investigate mineral weathering rates, identify factors that control and limit CO₂ removal, and develop robust approaches for carbon quantification. We are particularly interested in how mineralogy influences short- and long-term weathering rates and in deploying ERW in agricultural, forest, and mine environments where it can provide additional benefits for soil health and land management.
Related publications include Enhanced weathering as a farming practice, Are enhanced rock weathering rates overestimated?,and Incorporating enhanced rock weathering into sustainable.
Calcium carbonate formed from the reaction of atmospheric CO2 with CaO powder.
Carbonation of highly reactive minerals for CO₂ removal
Mineral looping is a proposed CO₂ removal technology that involves the calcination of magnesium and calcium carbonates to form oxide minerals that are highly reactive with atmospheric CO₂. Although this technology is promising, questions remain about carbonation rates, reaction pathways, and factors that may limit CO₂ uptake when these processes are scaled. Our research on MgO and CaO has shown that carbonation is strongly influenced by water availability, relative humidity, CO₂ supply, and the physical configuration of the reactive material. We have demonstrated that MgO carbonation to form dypingite can be limited by CO₂ supply, while CaO carbonation can be limited by passivation and CO₂ transport. Understanding these reaction pathways and limitations is critical for designing mineral looping systems that maximize CO₂ removal rates and can be effectively scaled.
Related publications include CO₂ capture using magnesium oxide powder, Direct air capture using calcium oxide powder, and Passive direct air capture using calcium oxide powder.
