Hitch is working on this problem alongside researchers Greg Dipple, team lead, and Ulrich Mayer, both of UBC's Department of Earth, Ocean and Atmospheric Sciences, and Gordon Southam, with the University of Western Ontario's Department of Earth Science. The collaboration is being funded by Carbon Management Canada, a Network of Centres of Excellence that funds research to produce the technology, knowledge, and human capacity that will reduce carbon emissions in the fossil energy industry and in other large-scale emitters.
Two of the team's primary goals are to measure the rate of CO2 fixation in mine waste rock and tailings in a lab setting and to speed up the process. Team members have already observed that CO2 fixation is greatly accelerated in mine tailings, presumably due mainly to the large surface area exposed and available to react after rocks are crushed into small particles.
Dipple's lab reports that their previous research has demonstrated that CO2 is trapped in mineral precipitates at rates of up to 50,000 tonnes per year within tailings during mine operations, and continues to be sequestered after mine operations cease. Rates of fixation are limited by the dissolution of CO2 in water and one area of investigation involves increasing the concentration of CO2 supplied to a slurry similar in chemical composition to tailings process water. Results show a 200-fold rate of increase over atmospheric weathering of some minerals by increasing the concentration of CO2 in the air passed through the slurry to 10%.
Hitch's lab is currently grinding rock and pre-treating the material in order to change its physical and chemical properties. Dipple's group will then examine the material's ability to fix CO2. The collaborating researchers hope to move to field trials in five years.
|Contact: Ruth Klinkhammer|
Carbon Management Canada