Chalmers University researchers develop a sustainable method for gold recycling using biodiesel

In Sweden, Chalmers University said that researchers at Chalmers University of Technology have developed an environmentally friendly method for recycling and purifying metals. 

“Pure metals have a number of uses in a modern society, not least for the development of green technologies. Our research shows how the metal industry can accelerate the transition from fossil to bio-based solvents,” saic Mark Foreman, Associate Professor of Chemistry at Chalmers.

“Even if the diesel used in the production and recycling of metals is not incinerated, there are many good reasons to switch to fossil-free alternatives. For example, in the production of oil, methane, which is a worse greenhouse gas than carbon dioxide, often leaks into the atmosphere. A lot of crude oil also contains toxic aromatic hydrocarbons, which damage the nervous system and are therefore dangerous for humans and animals to breathe in,” said Mark Foreman.

In the researchers’ method, gold scrap is dissolved in a mixture of hydrochloric acid and nitric acid.

Normally, when metals are mined or recycled, large amounts of fossil solvents are needed, but this doesn’t have to be the case, and the method developed by Chalmers researchers can be used for more metals than just gold, the university said.

“Our method is an environmentally friendly way of extracting pure gold from a mixture of many metals. Similar studies have been carried out in the past but have not achieved such a high purity of gold. The combination of biodiesel and malanomide is also special because it replaces both fossil diesel and other problematic chemicals,” he added.

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