Scientists have discovered by chance a much more ” green” method of gold mining compared to the already existing ones, which involves the use of toxic cyanides.
Gold, frequently used for the manufacture of jewelry, but also for electronics, is a delicate metal, being difficult to extract. The most modern procedures use highly toxic combinations of cyanides to bring gold to the surface, according to the publication Nature Communications.
Cyanides can remain in the soil, causing environmental problems, but also various diseases, this being also the subject of disputes related to a potential exploitation at Rosia Montana.
Recently, scientists at Northwestern University in the United States have come across an ingenious method of exploiting gold without the use of cyanides.
The secret is cornstarch! This modality involves, indeed, complicated chemical procedures, but it is cheap, environmentally friendly and does not contain the toxic ingredient.
The team led by a chemistry professor at Northwestern, Fraser Stoddart, discovered this method while looking for something else. One of the team members, Chemistry Doctor Zhichang Liu, was trying to make three-dimensional cubes made of gold and starch, in which he would store gases and molecules. But the mixture did not form cubes, but needles.
This seemed strange, so the team decided to reproduce the whole process. Thus, the researchers found out that a component of starch is the best insulator of precious ore. “Zhichang came across a kind of magic with which we can isolate gold from absolutely anything, in an environmentally friendly way,” Stoddart said.
Therefore, the interaction between the chemical constituent of starch and gold leads to the separation of the precious metal from other materials, including platinum, palladium and many others.