Carbonation of Mining Waste for CO2 Sequestration

Project description

The project will integrate chemical engineering and geochemical expertise to study carbonation across different pathways, including direct gas–solid and aqueous phase processes. Laboratory based experiments will be conducted on representative mining residues to quantify reaction rates and optimize conditions for enhanced carbon dioxide uptake. Methods such as mine waste pre-treatment, and process intensification will be explored to achieve efficient carbonation under energy- and cost-effective conditions. In this project, we propose a fundamentally different approach that involves capturing CO2 directly using reactive mine waste minerals, eliminating the need for solvents, thermal regeneration for solvents, and extensive compression infrastructure. The carbonation reaction between alkaline minerals and CO2 forms stable carbonates, offering a permanent storage pathway. In countries like India and Australia, where the mining industry is large, mining waste is an abundant and underutilised source of reactive calcium and magnesium, primarily in the form of oxides and hydroxides. Over a long period of time, this waste naturally carbonates in the environment, but under controlled process conditions the reaction can be greatly accelerated, maximising CO2 sequestration potential. This not only reduces emissions but also produces calcium carbonate as a co-product, creating economic incentives for adoption.

Outcomes

We expect to develop a good understanding of the kinetics of mine waste mineral oxide involved in the carbonation process under different process conditions of flue gas/captured carbon dioxide composition, mineral composition, gas, and liquid flow rates. We expect to employ this understanding in developing a process flow diagram that can be used by the mining industry to reduce their carbon footprint.

Essential capabilities

Critical thinking, problem solving abilities, good data analysis skills

Desireable capabilities

Familiar with methods like ICP-MS, XRD, TEM, SEM, Familiar with subjects like LCA, technoeconomic analysis, thermodynamics, reaction kinetics.

Expected qualifications (Course/Degrees etc.)

Undergrad/Masters in chemical engineering, geology, or environmental science