Innovation Exchange challenge: removal of Iron (Fe2+ and Fe3+) from mixed metal oxide powders

Mkango Resources are looking for ways to remove Fe(II) and Fe(III) from either mixed metal powder, a slurry of mixed metal powder, or a dissolved acidic solution.

Opportunity Details


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Successful projects will be awarded up to £25k over 3 months to explore their solution with the challenge holder with the possibility of further adoption upon successful trials.

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Challenge background

Mkango Resources process mixed metal oxide powders produced via processing of end-of-life permanent magnets into separated rare earth oxides ready to supply back into relevant supply chains. A major part of the process, taking around 4 steps, involves the removal of Fe(II) and FE(III)_ from the mixed powder stream. Mkango are looking for alternative ways to remove Fe(II) and Fe(III) from either the mixed metal powder, a slurry of the mixed metal powder or a dissolved acidic solution.

Solution requirements

Mkango are looking for novel ways to remove 60 % iron (II) from a mixed metal slurry containing other metals including (Nd, Dy, Cu, Pr, Al, Co and non-metals for example Boron). Working with the Challenge Holder the solution provider should aim to remove more than 99% of the iron present in the mixed metal material.

The solution must / should consider the scale of the pilot plant that is currently in development. The maximum scale is around 10 kg per day of powder to be processed which would result in around 6kg of iron to be removed.

If the baking step which oxidised the Fe(II) to Fe(III) is bypassed, the powder will not be oxidised and is therefore pyrophoric and will ignite in air, so health and safety considerations must be included.

The solution must avoid the removal of rare earth elements and cobalt from the powder unless they are separated into different streams.

The solution must also keep the slurry mixture below 65 degrees C and not involve high pressure processes. Any additives implemented within the solution need to be removed before continuing with the main process.

Any approaches that remove rare earth elements during the process will be considered out of scope.


Entrants to this challenge must be either:  

  • a UK registered business of any size
  • a academic institution
  • or a research and technology organisation (RTO)

Your project must:

  • have a grant funding request up to £25,000
  • last up to 3 months
  • carry out its project work in the UK
  • intend to exploit the results from or in the UK

Rewards and benefits

Selected applicants will be given an opportunity to pitch to Mkango. Successful solutions from the pitch day will be awarded up to £25k over 3 months to explore their solution with Mkango with the possibility of further adoption upon successful trials.

The benefits package for a successful applicant may also include:

  • Support from KTN
  • Support in the development of a prototype or pilot
  • Technical support
  • Invitation to attend or present at KTN events
  • A potential business collaboration
  • Investor introductions (if investment is required)
  • Support if any Innovate or similar competitions are relevant.

Related programme

Circular Critical Materials Supply Chains

Circular Critical Materials Supply Chains

This £15 million programme will support the development of resilient UK based supply chains for rare earth elements, with a focus on primary (mine to magnet) and secondary (End of Life to magnet) supply chains.


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