Mine waste has unexplored greenhouse gas trapping potential with a great economic value. According to Michael Hitch, a mining engineer and geologist at University of British Columbia, if mining companies recognize the potential, they could be able to offset CO2 emissions, and even start selling carbon emissions credits.
Although the process of mining results in high greenhouse gases release, the mine waste rock, rich in magnesium silicate, can react with CO2 and fix it in the form of magnesium carbonate. The estimated capacity of CO2 fixation can exceed 5 to 10 times the greenhouse gas production from mine operations, depending on the size of the mines.
This will not only change the dynamics of the mining operation, but it would affect the price of carbon emission credits. Naturally, in order to achieve this valuable result, the required reaction needs a boost.
A team led by Hitch at USB’s Department of Earth, Ocean and Atmospheric Sciences, together with a researcher from University of Western Ontario’s Department of Earth Science, are working to resolve this. They aim to measure the rate of CO2 fixation in mine waste rock and and the same time speed up the process.
Currently, the research at USB is at a stage of pre-treating the material in order to change its chemical and physical properties and test its ability to fix CO2. At the same time, UWO’s group is looking at the role of microbes in fixing the harmful gas in order to speed up the reaction.
Next step would be a computer simulation to predict the ability of rocks to sequestrate CO2 at specific mining sites. Hitch is already designing the extension to mining planning software, which will allow evaluation of the fixation capacity and it will provide individual rates for particular sites.
The team is very positive and optimistic about the idea, and they hope that one day their findings will be applied to broader CO2 sequestration projects.