Monday 22 November 2021

Could bacteria mean sustainable mining?

Researchers are engineering bacteria to extract rare Earth elements from ore.

The process of refining them after mining is harmful to the environment but are essential to modern-day necessities including computers, mobile phones, wind turbines, electric vehicles (EVs), rechargeable batteries and LED lights.

The researchers from Cornell University believe bacteria could be engineered to do the job in way that is not only cost-effective but also clean enough to meet American environmental standards.

The process would require far lower temperatures and pressures to extract the elements from the rocks – thus cutting down the energy-intensive process.

Lead author of the study Buz Barstow explained: “We’re trying to come up with an environmentally friendly, low-temperature, low-pressure method for getting rare earth elements out of a rock.”

Gluconobacter Oxydans is the bacteria that the researchers believe holds the answers; one of its genes produces an acid to break down phosphate, which if it can be controlled, could single-handedly draw out the necessary elements with just cellulose-derived sugars for an energy source.

Co-author Esteban Gazel commented: “I am incredibly optimistic. We have a process here that is going to be more efficient than anything that was done before.”

The US alone requires around 71.5 million tonnes of raw ore per year to extract 10,000kg of elements and the scientists are looking at feasible ways to keep up supply but in a way that leaves behind less of a carbon footprint.

The main issue, however, is that almost all refinement and extraction of the elements take place in foreign countries – particularly China – and the study explains that if countries like the US want to lessen the environmental impacts of their needs, they must control that resource.