As more is done to reduce the carbon footprint of the world we live in, many mining companies are looking to biotechnology for ways of reducing their impact on the environment. While bacteria, fungi and enzymes form part of this solution, plants play an enormous role in literally “greening-up” mine sites. Plants can be used to stabilise tailings storage facilities and, if the mining company uses suitable plants, these plants may offset some of their carbon tax liability.
Plants play an important role as indicators of underlying minerals – for instance only select plant species can grow in areas containing high levels of heavy metals, indicating an outcrop of a certain rock type or contamination of a certain area. In South Africa the endemic species Berkheya coddi, grows on the serpentine soils around Barberton, indicating the presence of nickel. This plant can also be used for biomining (agro-mining) as it accumulates nickel in its leaves, which can then be harvested and smelted to produce nickel metal.
More work is now being performed to find bioreagents to replace the more toxic metallurgical reagents such as xanthate. Plant extracts can be used to activate separation and a short practical and fun demonstration will be given – so please have a glass, a tot of gin, some tonic and some raisins available.