Audi will use alternative mining methods to reduce its environmental impact

Mining, a way of extracting the most important primary raw materials for a wide variety of industries, including the automotive industry, can only be carried out in a few places in the world, applying extraction methods that are usually not the cleanest.

In order to steer a more sustainable path, Audi engineers, in collaboration with scientists from the Freiberg University of Mining and Technology, conducted a two-year investigation into alternative methods of extracting raw materials, to give it a new approach. to your mining needs.

Bioleaching, the mining method that Audi studies

Current mining methods usually involve large-scale drilling and blasting tasks, which are highly invasive to the environment.

Audi, by the nature of its industry, has a strong interest in mining, as car manufacturing requires many mineral raw materials.

The automotive company, in collaboration with a team of engineers from Freiberg, is betting on a microinvasive, surgical-type procedure, with the projection of giving the mining operation a more ecological and efficient air.

The researchers tested the process, known as bioleaching, in situ. First, small holes were drilled into the ore vein in an underground min. Later. they use leaching to dissolve valuable elements from the ore. Interestingly, local bacteria are used in the process; Like tiny miners, these microorganisms help transfer metal ions into solution. Essentially, in this way, valuable elements are leached (separation of solids using a liquid solvent) from the mine walls and accumulate in these deposits. They are then separated using a two-stage membrane process. In this study, the researchers extracted indium and germanium, but in the future it might also be possible to extract cobalt and other valuable elements in the same way.

Separating valuable feedstock from a multicomponent mix at the mine has several advantages. The main one is that you don’t need to transport heavy liquids or waste energy for that, just transport what is really needed. In addition, microorganisms can be reused, which can be re-mined immediately. In addition, at a general level, mining executed under this technique offers superior performance, given its ability to perform in environments where the concentration of these elements is quite low.

Rüdiger Recknagel, Director of the Audi Environmental Foundation, noted in a company statement: “The process is environmentally friendly and innovative, as major mining activities are largely avoided and even small amounts of ore can be extracted”. Also, as a non-landscape-intrusive solution, researchers are considering introducing this method as an urban mining tool and for clearing older mines.

The image attached to this note, courtesy of Audi, corresponds to one of the tests carried out by the scientists who analyzed this proposal, even under harsh conditions: at a depth of 147 meters with an air humidity of 90% and ten degrees Celsius. The results obtained were positive: bioleaching and the separation of materials in situ works, which motivated the researchers to apply this process on a larger scale.