New method to obtain copper in a more sustainable way

Metals are essential materials for numerous industrial applications. Copper, in particular, is the third most important metal by volume of production after iron and aluminium. It is a strategic metal due to its use in electronics and communications, in the production of energy in wind generators or photovoltaic panels, as well as in the development of electric vehicles. The high demand for copper has led to search for its extraction from complex and low grade minerals, that is, minerals that have copper in their composition, but in low concentrations.

One of these complex minerals is chalcopyrite, which represents 80% of the world’s copper reserves and is often found in low-grade deposits, making it difficult to extract copper by traditional methods based on flotation followed by smelting. high temperatures. In fact, this difficulty means that the economic viability of these copper extraction methods is reaching its limit. It seems then that the hydrometallurgical treatment could be more adequate, however, in the case of chalcopyrite it is hindered by the high refractoriness of this mineral in acid media. For this reason, it is necessary to develop economically viable and environmentally friendly technologies that allow the use of copper from these deposits.

This was the objective of the work led by a team of researchers from the Polytechnic University of Madrid (UPM) in Spain who, in collaboration with the University of Zaragoza in Spain, set out to study the use of activated carbon derived from biomass as a catalyst in the leaching of copper from chalcopyrite. Test results have shown that this addition increases copper extraction from chalcopyrite by up to 20%. In addition, this activated carbon inhibits the formation of sulfur crystals and reduces the leaching of arsenic present in the copper sulfide concentrate, which reduces the environmental impact of the method.

Chalcopyrite sample. (Photo: UPM)

In short, and in the words of Ana María Méndez, a UPM researcher who participated in the study: “the results show that the use of certain activated carbons derived from biomass as catalysts in the leaching of metal sulfide concentrates can contribute to the development of sustainable hydrometallurgical; an issue, that of sustainability, fundamental in current mining.”

The research group continues to work on improving the process with the aim of reducing reaction times, catalyst recovery and increasing the percentage of copper recovery, which could mean a great advance in the hydrometallurgical treatment of chalcopyrite and other metal sulfides.

The study is titled “Biomass-derived activated carbon as catalyst in the leaching of metals from a copper sulfide concentrate”. And it has been published in the academic journal Minerals Engineering. (Source: UPM)