South African geologist and researcher, Tshiamo Legoale, has won top honours at the FameLab International 2017 contest for her ground-breaking metallurgical research, which looks at methods to “grow gold from wheat”, or rather use wheat as a gold hyper-accumulator.
The 27 year old was quick to point out that South Africa has an estimated 17.7-million tons of gold waste. “All this gold was mined out previously, but tiny amounts remain in the dumps,” she explains.
The research uses wheat as a gold hyper-accumulator, which essentially means wheat plants are used to harvest gold from mine dumps. In layman’s terms, the wheat is planted in the dumps, where enzymes found in the roots react with the gold and the plant absorbs it.
In an almost accidental manner, the gold is absorbed by every part of the plant except the seeds, in a process called phytomining, which means the next harvest of the plant can still be used as food if need be.
The extraction of the minerals using plants is done in an environmentally sound manner. In this case, the wheat can naturally take up gold and not be harmed – and it happens to do so in amounts larger than any other plant.
The root enzymes make the gold soluble, which means it can be stored in the stems and branches, and later – when those stems and branches are incinerated – the gold can be extracted from the ash.
The research represents a win on multiple levels. First, there are the obvious potential socio-economic benefits: food production, job creation, and phytomining itself is more economical than other contemporary mining methods.
Although in its pilot stages, Mintek, the metallurgical research and development organisation is hoping to roll it out more broadly within the next five years.