Mechanical Activation of Mine Waste Rock for CO2 Sequestration
A joint University of British Columbia and UNSW Australia/Australian Centre for Sustainable Mining Practices (ACSMP) are working on technology that enhances the natural process of converting CO2 into a thermodynamically stable mineral. Mineral carbonation has long been known as a mineralologic pathway to capturing and sequestering atmospheric CO2. Certain rock-forming minerals such as the magnesium silicate, forsterite (MgSiO4), when in the presence of CO2 and water, alters into a magnesium carbonate mineral, magnesite (MgCO3) in nature, effectively locking up or sequestering its gaseous cousin.
This fundamental process can be applied in an industrial setting such as a mine site where finely ground waste rock material (i.e. tailings) has experience mechano-chemical activation or the atomic restructuring of its crystal architecture. This structural disruption allows for a deeper, more complete saturation o f the particle in CO2, making the transformation quicker and more complete. Mine sites here in Australia are passively sequestering thousands of tonnes of CO2 annually in passive conditions. With the inclusion of technologies common in the mining sector, the potential to make mineral carbonation a tool for carbon management is one step closer.
The full article 'Mechanical activation of ultramafic mine waste rock in dry condition for enhanced mineral carbonation' was published in the international journal Minerals Engineering.