On 21st November, CHROMIC will participate in the satellite event of the Raw Materials Week 2019 named “How to define the impact of new technologies? A workshop on Sustainability assessment”. The workshop will gather a broad cluster of EU H2020 projects such as METGROW+(https://metgrowplus.eu/), NEMO(https://h2020-nemo.eu/) and CHROMIC itself, to discuss important issues regarding the economic sustainability and the beneficial impacts for the environment and for the whole society of the processes that are being developed to recover and valorize raw materials.

Questions such as how to determine the impact of resource recovery versus landfilling for such new processes and technologies will be presented and carefully addressed in an interactive debate aiming to formulate policy recommendations.

The event will take place at Le Plaza Hotel, Adolphe Maxlaan 118/126, 1000 Brussel.

To register, visit this page: https://apps01.vito.be/vitoevents/inschrijving/SustainAssessment2019.aspx.

The programme of the workshop is the following:

14.00: Welcome and introduction to the workshop

14.15: Sustainability in recovering metals from secondary resources: Approach and lessons learned in METGROW+ and CHROMIC (Yoko Dams, VITO and Koen Oorts, ARCHE)

14.35: Sustainability in the mining sector: Approach and lessons learned in NEMO (Andrea di Maria, KU Leuven)

14.50: Sustainability in enhanced landfill mining: Approach and lessons learned in NEW-MINE (Karel Van Acker, KU Leuven)

15.00: Summary and common issues

15.15: coffee break

15.45-16.45: Interactive discussion

16.45: wrap-up and outlook to next event

17.00 – 18.00: networking cocktail


Our project coordinator Liesbeth Horckmans (VITO) will be speaking at the EU Raw Materials Week 2019 (Brussels, 18th-22nd November). She was invited to present the progress of CHROMIC during the event named “Horizon 2020 Technology Success Stories”, which will take place on the 18th.

The Raw Materials Week is the most important EU annual event in the sector, gathering a wide range of stakeholders to discuss raw materials policy and initiatives, to provide guidance to the European Commission, Members States and private actors on innovative approaches to the challenges related to raw materials.

The “Horizon 2020 Technology Success Stories” event is focused on tangible results and impact of the H2020 projects in the area of raw materials and more broadly on the benefits that industry and society will gain from their developments. Horckmans will participate in the session “Raw materials processing and recovery”, alongside, among others, representatives of CHROMIC’s closely related projects FAME (http://www.fame-project.info/), METGROW+ (https://metgrowplus.eu/) and SCALE (http://scale-project.eu/).

This represents an important opportunity to team up among projects that share the same overall goals of developing technologies to strengthen the mineral sector and improve the circular economy in the EU. The exchange of outcomes and methodologies that will result from the joint participation to the event will contribute to the accomplishments of those objectives.

Furthermore, as CHROMIC is now entering its final year, the event will also be useful for taking stock of all the work that has been done so far, as well as for gaining extra momentum to proficiently deal with the challenges that remain to be tackled.

30 September 2019 Events

Matti Buyle with VITO presented his research work within CHROMIC at the 9th International Conference on Life Cycle Management (LCM), which took place on 1st – 4th September in Poznan, Poland. The LCM conference series is one of the world’s leading forums for environmental, economic and social sustainability, focusing on practical solutions for the implementation of life cycle approaches into effective decision-making, whether in science, industry, NGOs or public bodies.

Buyle gave a talk in the special session “Emerging Technologies – Sustainable Future or Rising Risks?”. His presentation mainly focused on estimating the environmental impact of a technology on an industrial scale, based on lab-scale data only. By using the preliminary data of one slag type (CS slag), he showed how in CHROMIC the first steps have been taken to upscale the lab results and get an idea of the environmental profile on an industrial scale.

As Buyle reported, “This is particularly relevant, as the first iteration in CHROMIC is done and the presented results – even though very preliminary and highly uncertain – could be used to streamline further research efforts in the next iteration”.  

On 26th September Kathy Bru with BRGM will present the CHROMIC project at a technical event organized by AFOCO, an association that deals with the valorization and management of industrial by-product, bringing together the main French operators in the sector. The event is called “Creating economic and environmental value? With the alternative materials of course!” and will take place in Lille, France.

All the details about the event at http://www.afoco.org/actualite.php?actualite=34

On 9th September dr. Niall O’Toole with HZDR presented a poster about CHROMIC at the ILSEPT 2019 International Conference on Ionic Liquids in Separation and Purification Technology (Melia Sitges, Sitges, Spain). The poster – prepared with HZDR colleagues Alexander Mansel, Norman Kelly and Christiane Scharf – was titled “Separation and recovery of chromium and vanadium from alkaline leaching solutions of Cr-V-bearing slags” and illustrated the research on solvent extraction carried out in CHROMIC.

ILSEPT 2019 is aimed at being an event in which researchers in academia and industry can share and discuss cutting edge results on the use of ionic liquids in separation applications. As reported by O’Toole, the CHROMIC research on solvent extraction met the interest of many participants working in the field of chemical separation.


The CHROMIC’s results will be presented at EUROCLAY 2019 (https://euroclay2019.sciencesconf.org/) by VITO’s researcher Elena M. Seftel. EUROCLAY is one of the most important scientific meetings in the field of clays and clay minerals, an event taking place every four years, in which the latest cutting-edge results of this research area are presented. The forthcoming edition of the event will be held at Pierre & Marie Curie University (UPMC) in the center of Paris, France, from 1st to 5th July.

Two contributions will show the research conducted by VITO within CHROMIC. The first one is a poster titled “Sorption of metal oxyanions from complex solutions by layered double hydroxide (LDHs) type anionic clays” will be part of the session “Layered double hydroxides for Future Earth”, whereas the second, an oral presentation called “Clay-based structured composites for oxyanions uptake from aqueous waste effluents” (realized in collaboration with the Laboratory of Adsorption and Catalysis of the University of Antwerpen), will be presented during the session “Clay and clay minerals in ceramics: from industrial to new hierarchical/textural materials”.

On Wednesday 26 June dr. Niall O’Toole from HZDR will give a talk about research carried out within CHROMIC at the European Metallurgical Conference (EMC), in Düsseldorf, Germany.

The topic of the presentation will be the development of a solvent extraction process for recovery of chromium and vanadium from steel slags, which is one of the main scientific and technological tasks tackled in CHROMIC.

The EMC is one of the most important international conference and meeting for metallurgists and engineers from the non-ferrous industry and research institutes in Europe. Besides its relevance, the event is particularly focused on the theme of sustainability, a founding theme of the CHROMIC project’s philosophy.

Further information about the European Metallurgical Conference 2019 at the conference website https://emc.gdmb.de/welcome/

VITO’s researcher Frantisek Kukurugya will present a paper at the Physical Separation ‘19 Conference, which will take place in Falmouth, UK, from 13th to 14th June. 

The conference, organized by Minerals Engineering International (MEI)(http://www.min-eng.com/), will bring together researchers and operators in the field of physical separation methods, which are of vital importance in the mining sector. On the second day of the event Kukurugya will present the paper titled “Up-concentration of Cr in stainless steel slag and ferrochromium slags by magnetic and gravity separation” (F. Kukurugya, P. Nielsen and L. Horckmans), which shows results obtained by VITO within Work Package 2 of the CHROMIC project.  

Further information about Physical Separation ‘19 at the conference website (http://www.min-eng.com/physicalseparation19/)


CHROMIC is going to participate in the Raw Materials Summit 2019, which will take place on 20-22 May in Berlin, Germany.

The Raw Materials Summit is the flagship event organized by the EIT (European Institute of Innovation and Technology) RawMaterials (link https://eitrawmaterials.eu/), the largest consortium in the raw materials sector worldwide.

The summit will bring together experts from all around the world to discuss innovation and new technologies encompassing the entire raw materials value chain. Also, topics such as strategies concerning supply and access of raw materials, European industrial competitiveness and innovation capacity will be covered in-depth, providing a wide understanding of the EU positioning concerning the energy transition and the impact this will have on raw materials supply and policies.

CHROMIC couldn’t miss the event and will contribute by bringing the broad scientific and technological expertise it has gained in the field. Liesbeth Horkmans – the CHROMIC project coordinator – was invited to give a talk about CHROMIC in the “H2020 – research along the raw materials value chain” session of the summit.

Further information about the event here (https://eitrawmaterials.eu/raw-materials-summit-2019/).


Remember the old arcade games from the 80s? No fancy hyper-realistic graphics, no third dimension. Nonetheless, in just a few pixels, you could live the most amazing adventures: Rescue abducted princesses, save Earth from alien invasions, flying spaceships through asteroids and… eat a lot of fruit while staying away from indigestible ghosts.

Yes, that was Pacman’s thing. The yellow pal was on a mission to seek and collect all the pieces of fruit that were disseminated within a labyrinth, avoiding contact with the ghosts.

What does that have to do with solvent extraction? Regrettably, there are no arcades at CHROMIC facilities, yet Pacman’s lifestyle comes in handy to describe the object of this Getting to Know, as we’ll see in a moment.

After the “tea preparing” stage (i.e. leaching stage) of the metal recovery process, we were left with our valuable metals (Cr, Mo, V, Nb) dissolved in a complex solution containing solvents and some impurities: The final step of the recovery process is then that of separating the metals from the solution, and possibly enrich them. That can be achieved very efficiently by cunningly combining different chemical techniques, one of which is solvent extraction.


CHROMIC Podcast – Episode 6 is about solvent extraction. Click here to listen to the podcast


This method is used to separate compounds based on their solubility in two different immiscible liquids, which in most cases are an aqueous solution containing the target element(s) and an organic compound. To do that, the two liquids (or “phases”) are mixed, so that the solutes can distribute between them until equilibrium is established, and the two liquids are separated again. The transfer of species from one phase to the other is driven by the chemical potential, which by the end of the reaction brings the whole system to a more stable energetic configuration. The liquid containing the desired solute is called the “extract” and what is left behind in the other solution is called the “raffinate”.

Going back to the analogy we started from, we can conveniently link the elements at play with the characters and dynamics of the beloved arcade game. The organic compound is represented by Pacman itself, the fruits are the valuable metals, and the ghosts are the impurities which Pacman does not want to get into contact. The solutions are immiscible, but they can be mixed through stirring, so Pacman comes into contact with the fruits, transferring them into the organic phase. When Pacman has explored the whole labyrinth, the mixing stops and the two solutions separate, leaving the ghosts and impurities in the aqueous leachate, whereas Pacman and the fruits are located in the organic phase. In a second step another solution can be added, which encourages Pacman to release the fruits into the aqueous phase, so to finally get a pure solution of our valuable metals.

Aside from this simplified image, the process is indeed in principle pretty straightforward, but in practice very challenging. First off, in case of the reactive extraction of metal ions selecting the right extractants, modifiers and solventsfor the task is far from being trivial. A number of features have to be taken into account: The ability of the extractant to bind to the target metal to a much larger extent than the rest of the components in the mixture; the irreversibility of the reaction must be guaranteed, in order for the dissolved components not to go back to their previous form; the compound formed after the reaction has taken place must be easily recoverable. Other factors that affect selection for the composition of the organic phase are its solubility in the aqueous phase and its long term stability; for industrial applications other factors like low toxicity are important, too. . Furthermore, the conditions under which the extractive reaction takes place greatly impact on the final result, and need to be fine-tuned. For instance, it is very important to maintain  a stablepH and a constant temperature of the compound during the extraction process, as well as to find the right residence time (the time in which the two solutions are in contact) and the suitable phase ratio so that the reaction is optimized.

Solvent extraction is widely used both on small – chemical laboratories – and industrial scale, due to its cost-effectiveness and capacity of separating the required components without altering their properties. It is for instance applied in the production of fine organic compounds, the production of vegetable oils and biodiesel, the processing of perfumes. It is also employed in the petrochemical refining industries, where extraction allowsthe procurement of pure petroleum from the impurity-filled crude oil. From a hydrometallurgical standpoint, the ability to selectively separate out even very similar metals makes solvent extraction the way to go for separation and purification of elements like uranium and plutonium, cobalt and nickel, as well as rare earth elements.

Depending on the application, different devices and apparatus can be used to perform solvent extraction. Those commonly include so called separatory funnels (at lab scale), and machines that bring the two liquids into contact with each other, like extraction columns  and mixer-settlers.

In CHROMIC the research on solvent extraction to recover Cr, V, Mo and Nb is brought forward by HZDR, while other methods which are to be combined with solvent extraction, like selective precipitation and sorbent materials are investigated respectively by BFI and FehS, and VITO. Lastly, TUK focuses on the final processing.

No arcade game characters are being harmed during the process.

(Photo: bdyczewskiPixabay )

This project received funding from the European Union’s Horizon 2020 Research and Innovation program under Grant Agreement n° 730471

effiCient mineral processing and Hydrometallurgical RecOvery of by-product Metals from low-grade metal contaIning seCondary raw materials