MSA: a green solvent for REE recovery

Within the EU H2020 REMAGHIC project, SIM² KU Leuven developed a process to recover rare earths from lamp phosphor waste by dissolution in concentrated methanesulphonic acid (MSA), a green solvent known for its characteristics of thermal stability, low toxicity and biodegradability. (Leuven, 2/8/2018)

Besides yttrium and europium, lamp phosphor waste represents an interesting source of the valuable rare earth terbium, which is present in the green phosphors LaPO4:Ce3+,Tb3+ (LAP), CeMgAl11O19:Tb3+ (CAT) and (Ce,Gd)MgB5O10:Tb3+ (CBT). The current treatment technologies for terbium recovery from lamp phosphor waste involve long leaching times and harsh conditions, due to the difficulty of dissolving rare earth phosphates.

Graphical Abstract MSA paper RSC AdvancesIn this paper we present a milder approach for dissolving the LAP phosphor, by making use of concentrated methanesulphonic acid (MSA, CH3SO3H) as leaching agent. MSA is labelled as green solvent: it is biodegradable, it has a high boiling point and it is thermally stable so that it can be used at temperatures up to 200 °C. This first leaching step with concentrated MSA is an example of ‘solvometallurgical leaching’ or ‘solvent leaching’. Solvometallurgy is a new branch of metallurgy which is receiving increasing attention among the scientific community. Solvometallurgical processes are based on the use of solvents other than water and normally show some advantages compared to the classical hydrometallurgical process, such as higher selectivity and the reduction of the waste streams to be processed afterwards. In our process the valuable rare earth terbium was quantitatively leached from a synthetic LAP phosphor in only 1 h.

When the process was applied on a real lamp phosphor residue (obtained after leaching the lamp powder with H2SO4), about 74% terbium was dissolved. This is due to the fact that in the real waste not all the green phosphors is LAP, but some of the terbium is in the phosphors CAT and CBT, which cannot be dissolved by concentrated MSA. After leaching, rare earths are recovered though a separation step performed by solvent extraction with di-(2-ethylhexyl)phosphoric acid (D2EHPA). By contacting the diluted leachate with 70% D2EHPA in xylene, terbium was selectively extracted over lanthanum and cerium and afterwards stripped by an oxalic acid solution. The raffinate coming from this first solvent extraction step was subjected, after further dilution, to a second solvent extraction step aimed at extracting La and Ce, which were then stripped with oxalic acid, as in the case of terbium. The obtained rare earth oxalates were finally calcined in order to get the corresponding oxides (Tb4O7, CeO2, La2O3). These mixed REE oxides can be further purified by solvent extraction in order to remove the co-extracted yttrium, europium and gadolinium, which are inevitably dissolved in the selected leaching agent.

Full reference paper

Lukas Gijsemans, Federica Forte, Bieke Onghena, Koen Binnemans, Recovery of rare earths from the green lamp phosphor LaPO4:Ce3+,Tb3+ (LAP) by dissolution in concentrated methanesulphonic acid, RSC Advances, 2018, 8, 26349-26355, DOI: 10.1039/C8RA04532A


This work has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 680629 (REMAGHIC: New Recovery
Processes to produce Rare Earth-Magnesium Alloys of High Performance and Low Cost) (project website: The authors acknowledge Relight
Srl (Rho, Italy) for providing the residue.

Bio first author

Lukas Gijsemans imageLukas Gijsemans was born in 1993 in Belgium and graduated as a master in chemistry in 2016. He immediately started working with Prof. Koen Binnemans at the Lab for Inorganic Chemistry (LIC) at the KU Leuven as a research associate. The main focus of his research is solvometallurgical leaching and solvent extraction of industrial waste.

Call for applicants: 15 PhD positions in CHARMING

The EU Horizon 2020 MSCA-ETN CHARMING consortium is looking for a dynamic team of 15 bright and enthusiastic PhD students. The call for applicants is now officially open. PhD candidates need to apply on-line through the CHARMING application tool. The deadline for on-line applications is October 15, 2018. 

On-line Recruitment Procedure (APPLY HERE)

All applications proceed through the on-line recruitment portal on the website. Candidates apply electronically for one to maximum three positions and indicate their preference. Candidates provide all requested information including a detailed CV (Europass format obligatory) and motivation letter. During the registration, applicants will need to prove that they are eligible (cf. ESR definition, mobility criteria, and English language proficiency). The deadline for the on-line registration is 15 October 2018. The CHARMING Recruitment Committee selects between 20 and maximum 30 candidates for the Recruitment Event which will take place in Leuven, Belgium (13 November 2018). The selected candidates provide a 20 minute presentation and are interviewed by the Recruitment Committee. Candidates will be given a domain-relevant peer-reviewed paper (prior to the recruitment event) by their prioritised Supervisor and will be asked questions about this paper during the interview to check if the candidate has the right background/profile for the ESR position. Prior to the recruitment event, skype interviews between the Supervisors and the candidates are recommended, along with on-line personality tests.

Key dates

• 30-6-2018: Launch 15 ESR positions

• 15-10-2018: Deadline for on-line application

• 30-10-2018: Circulation list “preselected candidates”

• 13-11-2018: CHARMING Recruitment Event

• 20-11-2018: Circulation list “recruited CHARMING ESRs”.

• 12-2018 – 04-2019: Targeted starting date for ESR contracts

Full details about 15 positions and procedure

Download here

General coordinator for ETN CHARMING:
Prof. Tom Van Gerven (KU Leuven)
+32 (0) 16 32 23 42

General contact person for ETN CHARMING:
Mrs. Rabab Nasser (KU Leuven)
+32 (0) 495 59 38 21

New Phd on The use of hydrogen to extract NdFeB and REEs from Assemblies

Christian JĂśnsson (2)

On June 7th 2018, Christian Jönsson successfully defended his Ph.D. thesis at the University of Birmingham, UK. The work was part of the EU FP7 MC-ITN project EREAN, short for ”European Rare Earth (Magnet) Recycling Network”, and was supervised by Professor Allan Walton.
The title of the thesis is ”The use of hydrogen to extract NdFeB and REEs from Assemblies”, and it investigates:
• Potential WEEE sources for NdFeB recycling. Working together with two other EREAN researchers, a wide range of products were dismantled and assessed at STENA’s recycling plant in Halmstad, Sweden. It was concluded that loudspeakers from flat screen TVs are the best WEEE NdFeB recycling candidate after HDDs.
• How hydrogen can be used as an extraction tool of NdFeB from assemblies. This has previously been demonstrated on HDDs, and this thesis showed that the same principles can be used on automotive rotor magnets. However, the rotor magnets react much slower due partly to a higher Dy content, which makes it unfeasible to operate at atmospheric pressure.
• How hydrogen can be used in the separation of REEs from the NdFeB alloy.
1) A range of hydrogen treatments were applied to the as-extracted powder to find the optimal version for oxidative roasting. It was found to be the as-extracted HD powder due to its highly reactive oxidation pathway, the NdH2.7 grain boundaries.
2) The disproportionation reaction (>650 C in hydrogen) dissociates Nd2Fe14B into its elemental constituents on a nano-scale and is the first part of the HDDR process where the hydrogen is immediately removed to recombine the elements into fine Nd2Fe14B grains.
By doing the opposite, holding the temperature high in hydrogen for extended hold times, the microstructure coarsened and formed large pools of NdH2. This is believed to open up for the physical separation of REEs from NdFeB, a whole new recycling concept!

Umicore vacancy: Innovation Project Manager

For its Group Research & Development located in Olen (Belgium), Umicore is currently looking for an Innovation Project Manager. This is a final call for candidates who hold a PhD or Master with more than 5 years of relevant experience in chemical, metallurgical or environmental engineering. (Leuven, June 2018)

Job Description

Do you have a strong background in recycling and extraction, in processes and technologies? Are you passionate about learning and sharing knowledge, and about generating new ideas and insights to advance and accelerate research initiatives? Do you want to work on research projects with a longer time horizon? Are you a strong networker and communicator, connecting internally with a broad network of colleagues, and externally with Umicore’s network of university, research institute and industry partners for open innovation? For its Group Research & Development located in Olen (Belgium), Umicore is currently looking for an: Innovation Project Manager


  • You manage innovative projects with a longer time horizon in the field of recycling and extraction.
  • You contribute to and extend our external network for collaborative research, in search for new opportunities.
  • You actively develop your expertise, and share it within the organization. Moreover, you facilitate the connection between outside knowledge and developments, and the relevant colleagues inside Umicore.
  • You interact with internal and external customers and stakeholders.
  • You are accountable for the results, timing and budget within your responsibilities.
  • You take responsibility for environmental, health and safety aspects.


 You hold a PhD or Master with more than 5 years of relevant experience in chemical, metallurgical or environmental engineering or an equivalent area.

  • You are creative. You like exploring and are open minded towards new ideas and concepts. You stimulate your own and others’ creativity and innovation.
  • You are a strong communicator, verbally and written, with excellent networking skills, able to proactively build functional relations inside and outside the company.
  • You have good analytical skills, able to assess and summarize (numerical) information and share knowledge and expertise with others.
  • Your entrepreneurial mindset is able to evaluate new ideas and their technical and economic feasibility.
  • You are skilled in organizing and planning. You are result-oriented.
  • You are fluent in English both written and orally. You speak Dutch or you are prepared to master it rapidly. Knowledge of French or German is a plus.
  • You are willing to travel abroad.

Application closes on 8th of June 2018. Apply here. Umicore offers several other new positions which are worth cheking out.

Meet our SIM² Researcher: Isadora Reis Rodrigues

Isadora Reis Rodrigues is a PhD student at the Department of Materials Engineering (MTM) at KU Leuven. She is working on the development of a physical separation method for rare-earth ions using strong magnetic fields. The work is performed under the supervision of Prof. Jan Fransaer (MTM) and Prof. Koen Binnemans (Dept. of Chemistry). (Leuven, 7-5-218)

Why did you choose to work in Belgium?

I have always been a traveler: before Belgium I lived in Canada, South Asia, and North Africa. When I moved to Europe, I spent some time moving between places. I was first in Antwerp (Belgium), then in Thun (Switzerland), and finally in Lille (France). Among these 3 European countries, Belgium was by far the country where I felt the most at home. This is definitely the first reason why I looked to come back here when I decided to do my PhD. I may add the very fortunate feeling of having Brussels so close, it is not only the capital of Europe, but also this colourful melting pot of so many cultures, which I like a lot.

What are you working on?

I am working in a project where we use strong magnetic fields to develop a physical separation method for rare-earth (RE) ions. Many elements from the RE group are considered critical because of their role in the production of permanent magnets, the use in green technologies and in many daily life devices. More sustainable routes for the production and recycling of these metals are crucial. In this sense, the big picture of the project I work on is to develop a cleaner alternative for the chemical separation methods which are traditionally available. The idea of a magnetic separation method is particularly interesting for RE ions, as across the RE group the magnetic properties vary significantly (i.e. Y3+ is diamagnetic, Nd3+ is paramagnetic and Dy3+ is strongly paramagnetic). The use of magnetic fields to manipulate macroscale particles is a well-known method applied to the separation of magnetic materials. However, the effect of magnetic fields on small molecules and ions, is rather controversial, which is at the same time challenging and exciting.

What attracts you in the research project you are working on?

First of all, I like to think my work can have an impact towards cleaner industrial processes. The environmental aspect is since long time a crucial engagement for me. Secondly, the fact that together with few other research groups around the world, we are still looking for very fundamental answers. Trying to solve this “magnetic” scientific puzzle is quite interesting: how the magnetic force acts in a solution of ions, the impact of the experimental conditions, etc. Each small step is constantly teaching me something new. Finally, most of my work has been based on a technique called Mach-Zehnder interferometry: it is very visual, we can actually see the mobility of the ions during the magnetisation experiments. This brings a very interactive-colourful perspective to my work. Ah! and please, let me not forget about one very important part, the colleagues with whom I share the daily lab life, they make all the difference.

What helps you to overcome the difficulties of life?

One of the things that helps me a lot, is to simply work. I figured out that active mind and body are very useful tools to build on and to sustain the inner strength to face life issues. Other thing that I cherish a lot is to have few small rituals to bring a type of meaningfulness to the everyday life, this is also one of my good anchors.

When are you the happiest?

When I am drinking chimarrão (typical tea from south Brazil) in my mom’s sunny garden and my two nieces are around. Also, I feel very happy when I have the chance to teach yoga or when I am in my kitchen cooking something vegan for friends.

Bio Isadora Reis Rodrigues

Isa_AntwerpIsadora Reis Rodrigues was born in Cruz Alta, Brazil, 1982. In 2004 she obtained a Bachelor Degree in Industrial Chemistry at the Universidade Federal de Santa Maria. She moved to Canada in 2007 to conduct her Masters Studies at the UniversitĂŠ de MontrĂŠal, where she worked in the field of lithium-ion batteries. Her growing interest in sustainable technologies in general, and rechargeable batteries in particular, brought her to work for IREQ (Canda) and FPTI (Brazil), both research institutes active in the energy sector and engaged with e-mobility. Currently, she is in her third year of her PhD studies at the Department of Materials Engineering at KU Leuven, working on the magnetic separation of rare-earth ions, under the supervision of Prof. Jan Fransaer (Dept. of Materials Engineering) and Prof. Koen Binnemans (Dept. of Chemistry).