Developed at the University of Leicester, deep eutectic solvents (DES) are a nontoxic, environmentally benign and chemically stable subset of ionic liquids. They can be made by combining an organic salt, such as choline chloride (vitamin B4), and a hydrogen bond donor, such as urea or citric acid.

According to Argo, DES have already been used to replace water and toxic chemicals in a range of industries, and can also extract a wide range of metals contained in ores or tailings via dissolution into the specially designed solvents.

Accordingly, the company is targeting commercial uptake of DES technology in four key areas, namely mining, artisanal mining, e-waste recycling and remediation.

Gold is currently commonly recovered using cyanide, and in the case of artisanal mining, the use of mercury.

Argo said DES had demonstrated gold dissolution rates 80% faster than with cyanide, and the technology had the potential to eliminate the need for smelting.

DES could also offer a safe alternative to mercury in artisanal gold mining, as well as being able to dissolve toxic heavy metals from contaminated sites.

Argo is now looking to secure investment to conduct full-scale pilot test work on a range of feed material.

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Join us at Future of Mining EMEA on September 4-5, 2019, in London, UK, where Argo Natural Resources' Samantha Hyde and Professor Gawen Jenkin from the University of Leicester will discuss 'Extracting future mineral resources with cutting-edge technologies'