Supporting global net-zero carbon: Unlocking the potential of mine waste to capture greenhouse gases

Overview - The use of rocks and minerals to capture CO2 and other Green House Gases (GHG) will play a key role in the transition to reduce net CO2 emission. Rock waste from mining and drilling is currently underutilised as it is generally enriched in toxic elements and chemicals. However, suppose these toxins can be stabilised, and the waste processed to capture GHG’s. Then rock waste would be an asset, supporting the UK’s commitment to meet net zero, and safe for reuse as aggregate material in construction. The mining and civil sectors are responsible for 6-9% of global CO2 emissions, mainly through the processing of rock; carbon capture by mechanochemical reaction offers excellent potential to trap CO2 and stabilise toxins without introducing any additional embedded CO2 costs.

This project explores the use of mechanochemical reactions in mine waste to stabilise toxins and capture CO2—the research aims to stabilise CO2 and PTEs (potentially toxic elements) to enable the waste to be safely used as aggregate. Mechanical activation of rock waste generates charged chemical species, allowing GHG capture by chemical adsorption into rocks at low pressures and temperatures. The PhD project aims to understand the mechanochemical reactions involved with GHG sorption and assess the long-term environmental stability of trapped GHG’s and PTEs. The candidate will also investigate the effect of mechanochemical CO2 trapping on PTE mobility compared with untreated rock waste. This project aims to trap CO2 and make mine waste/drill cuttings safe to use as aggregates/fill. This reduces net emissions in the sector and increases the economic value of waste materials in a future circular economy.

Methodology - This project will utilise a full suite of analytical testing equipment, including CHN-elemental analysis, thermal desorption mass spectrometry, SEM, FTIR, ICP-OES, GCxGC-ToF, IC, IRMS, hosted in the Civil and Environmental Laboratories at the University of Strathclyde to analyse waste rock and leached waters from mechanochemical reactions. The candidate will carry out grinding and rock fracturing experiments to examine the trapping potential of CO2 under different conditions. 

Training & Skills - This project will suit a student interested in geochemistry, environmental chemistry and material science using experimental techniques. You will learn basic laboratory techniques and will be trained on regularly used analytical equipment. In addition to laboratory training, you will also learn how to integrate different chemical data sets to gain an insight into fundamental mechanochemical reactions between gas-rock and water-rock reactions.

As a PhD student at the University of Strathclyde, you will also complete the University of Strathclyde’s acclaimed Research development program, acquiring cross-disciplinary skills to broaden career prospects in various industries.