Leaching gold with thiosulfate is a well-known process – but until now, no one has developed a sufficiently effective method for separating gold and copper after leaching.

Cyanide leaching is the conventional method for gold leaching, but it poses significant risks to both humans and the environment. Therefore, Chromafora has modernized thiosulfate leaching and combined it with its unique metal separation technique SELMEXT™. The result is cyanide- and toxin-free gold extraction from electronic waste, mining waste, and other residues.

Since spring 2022, Chromafora has been conducting a scale-up study to extract gold from mining materials. This is being done in collaboration with BJÖRKDALSGRUVAN AB, one of northern Europe’s largest gold mining companies. The project will conclude and be summarized at the end of September, but the results already look promising.

“Björkdalsgruvan has complex material to handle, but the scale-up has been successful and what we are presenting signifies a major breakthrough for non-toxic gold leaching,” says Johan Berg, application manager at Chromafora.

After the summer, Chromafora will proceed with new gold projects in a larger facility and is now seeking more partners in recycling, metallurgy, technology, and the mining industry.

Chromafora is seeking more partners in recycling, metallurgy, technology, and the mining industry. Interested in learning more? Contact Johan Berg at johan.berg@chromafora.com.

The gold leaching project is a part of the strategic innovation program Swedish Mining Innovation – a joint initiative by Vinnova, Formas, and the Swedish Energy Agency.