PROMT: Philippines Remediation of Mine Tailings

We will work with researchers and mining companies in the Philippines to discover new ways to manage metal mine wastes, to clean up pollution, and to make soils to support plant growth and allow the land to be reused. More and more metals are needed for the low carbon technologies to minimise the effects of climate change. The Philippines is the fifth most mineral-rich country in the world and will benefit from this increased demand, but sustainable mining technologies are needed to prevent negative impacts on the environment and surrounding communities.

Traditional mining and mineral processing technologies consume large quantities of fresh water, produce CO2, can contaminate water, and compete with local communities for resources. They also produce large amounts of mine waste - uneconomic rock, and wet slurries of finely-ground minerals left over from mineral processing, known as tailings. These are deposited behind constructed dams as tailings storage facilities. It is estimated that in the Philippines about 33 million tonnes of tailings are produced annually - about six times the weight of the Great Pyramid. Tailings storage facilities at both operational and closed mines pose environmental hazards; failure could cause contaminated materials to be released affecting people and ecosystems. The risk of failure is increased in the Philippines, due to the rugged topography, high rainfall, and frequent earthquakes.

Our research project will investigate new sustainable technologies to minimise the environmental hazards of mine tailings. We will apply our research to both nickel and copper-gold mines which make up 99% of the value of metallic minerals mined in the Philippines. Our project brings together three science areas that are vital for innovation: (1) we will show how tailings storage facilities can be monitored in real time to allow reactive management to environmental changes; to achieve this we will use emerging technology in geophysical tomography and remote sensing to monitor and understand tailings behaviour in 4D (2) we will investigate novel environmentally-benign solvents as a new method to dissolve metals from modern and abandoned tailings and test their application at mine sites; this will allow more metals to be recovered with economic value and also benefit tailings management by decontaminating hazardous components (3) we will study how plants and microbes colonise mine wastes, how this is affected by the use of solvents, and identify the best ways to promote biological growth. This will not only rehabilitate the land and allow it to be reused for agriculture or wildlife, it also minimises environmental hazards by improving the stability of the tailings and decreasing their toxicity.

Whilst these approaches have been applied separately in other settings, this will be the first time that they have been used in combination to address the pressing issue of tailings remediation. By integrating these novel approaches we will find synergies that will deliver a step-change in innovation and enable us to achieve our ambition of sustainable tailings management. The outcomes, impacts and benefits of this research will be to decrease impacts from tailings to local communities and the environment, improved social license to operate for mining companies, reduced long term liabilities and risks from abandoned sites, and potential sources of revenue by recovery of additional metals and land re-use.