Circular economy and bio-economy are cornerstones for building an environmentally responsible future. The European Union and its Member States are promoting the development of tools that transform industry and economy by making them environmentally responsible, ensuring sustainability in their processes and making them independent of the use of natural resources.

This is done through new instruments such as the European Green Pact, the European Action Plan for the Circular Economy or the new European Industrial Strategy, all of which have been included in Spain’s national development plans in line with this objective of transformation and transition towards a sustainable economy.

Within this framework of transformation of the economic model, industrial biotechnology constitutes one of the bases of the bioeconomy, whose development will contribute to achieve the objectives established by the European Strategy on Bioeconomy, currently under revision. In this line, the European Union recognises biotechnology as a key enabling technology (KETs) for European industrial policy and the transformation of today’s economy towards a sustainable bio-based economy with potential to address the social challenges that the world faces today.

In the field of biotechnology, recent years have seen the strong emergence of biohydrometallurgy as a biological, sustainable process with potential to be widely deployed for the bioremediation of strategically important raw materials such as high value metals or critical raw materials, present in different by-products – electronic and electrical waste, catalysts or minerals -, thus contributing to the European objective of ensuring the supply of sustainable raw materials – in particular, critical raw materials through the recycling of critical and/or strategic metals and their reintroduction into final applications.

To achieve this biorecovery, technologies based on bioprocesses such as bio-oxidation or bio-leaching are currently under development which allow, in different stages and combined with other possible chemical and/or thermal processes, the precipitation of the metals of interest to be obtained

Biotechnological process equipment

This type of bioprocess can be applied, for example, for designing sustainable recycling systems that allow the extraction of metals such as silver, gold or cobalt from electrical and electronic waste. They can also be of great help in the mining industry through the development of bio-mining processes for the selective extraction of different raw materials, including Critical Raw Materials (CRMs), from low-grade minerals that are not currently exploited or even from products of secondary origin as waste from the different mining processes.

These types of processes are promising – recent investigations show very positive results – but they still require research efforts for validation and optimisation. Work is currently underway to improve bioextraction yields, making the metals of interest more accessible, as well as optimising the parameters that have the most influence. It is necessary to identify the most effective strains of microorganisms, the better work conditions of the chosen bioprocesses, it is also necessary to adapt each one to the different nature of both the starting waste and the raw materials to be extracted, etc. It is also necessary to scale up these processes at an industrial level so that they can be adapted to the complex real conditions of a waste treatment plant or mine (pH, mineral complex, etc.), trying to obtain high recovery rates, flexibility, purity, environmental and cost efficiency, and under safe conditions, so that in the future they can constitute a viable industrial reality.

A very important feature of these technologies is their potential application in the recovery of Critical Raw Materials, identified by the European Union as those of greatest importance to the European economy and whose supply presents the greatest problems. The European Union is not unaware of the need to advance in the research and development of these innovations and has therefore launched different initiatives in this respect, such as the European Innovation Partnership Raw Materials or the Raw Materials Initiative, to promote innovation, recycling and the sustainable supply of raw materials from European sources.