BRAIN Biotech partners with PX Group in microbial gold recycling

Industrial biotech specialist BRAIN Biotech and PX Group have extended its collaboration in highly effective microbial gold recovery from e-waste.

Back in 2017, BRAIN Biotech developed a container-based mobile pilot plant for the bioleaching of metals dubbed BioXtractor. An advanced version called BioXtractor V2 was financed by PX Group and is now jointly owned by BRAIN Biotech and PX Group. It is located at the PX Group’s site in La Chaux-de-Fonds, Switzerland, where the gold-containing side streams are gathered and processed. The partners now aim to test its performance in a production environment (cubic metre scale) and have refined the BioXtractor plant to the point where the first gold nuggets (BioGold™) were successfully produced from urban waste in 2024.

“Our goal is to integrate the biological extraction process as a key component alongside other technologies to enable the recycling of all materials in e-waste, including copper, plastics, and other metals,” said Dr. Alexandra Levesque, Head of Chemical R&D at PX Group.

Approximately 4000 tons of gold are consumed worldwide each year. The production of 40 mobile phones requires approximately one gram of gold. To extract this amount of gold, around one tonne of ore normally has to be mined and processed by a not sustainable process consuming  a lot of energy and chemicals. Urban mining solves the problem by closing the loop extracting the precious metal from electronic scrap. Every German for example produces 10 kilograms of e-waste every year.

Most existing e-waste recycling processes are under environmental scrutiny because they rely on energy-intensive smelting processes that emit large amounts of greenhouse gases. With rising energy and CO2 costs, smelting for recycling is not a viable long-term option for the future. For this reason, BRAIN Biotech developed the microbial bioleaching process for the recovery of precious metals at its Zwingenberg site to bring it to pilot scale together with an industrial partner.

The BioXtractor was intentionally designed and constructed as a mobile unit, allowing the biological extraction process to be tested directly at potential application sites and integrated into existing process chains. Its installation at PX Group‘s industrial site in Switzerland now serves as the foundation for validating and further developing the process at a pilot scale.

ing conditions of local mining communities. The Group is committed to responsible gold production and works on a daily basis to reduce its environmental footprint, by implementing measures to support artisanal mines in abandoning the use of mercury in their gold extraction.