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Försök pågår med klimatneutral framställning av molybden
I Sverige förbrukas 8 500 ton av metallen molybden årligen, framför allt vid framställning av högpresterande, rostfritt stål och verktygsstål. I laboratoriemiljö på Swerim pågår just nu försök med att reducera molybdenoxid med vätgas. I industriell skala skulle det innebära stora miljövinster – och sannolikt även bli mer kostnadseffektivt.
Following a successful prestudy of hydrogen reduction using molybdenum oxide during 2021, practical fluidised bed trials will be conducted at Swerim during spring 2023.
The work is funded via Vinnova and is being carried out as a thesis project by Towa Erikson from Uppsala University. Swerim's Lars-Olov Nordberg is supervising the trials.
"We want to demonstrate that it is possible to generate a molybdenum product without slag residues. The trials are being carried out in a test rig funded by Swerim, in which up to 200g of sample material can be fluidised and tested under controlled conditions.”
Currently, molybdenum oxide is produced via reduction to ferromolybdenum, using aluminium and ferrosilicon, which generates large amounts of slag, a residual product that must be disposed of.
The advantages of producing molybdenum via hydrogen reduction of molybdenum oxide, as compared to the conventional method, are threefold:
- Carbon dioxide emissions are eliminated entirely.
- The need for landfilling slag is eliminated entirely.
- Transport of raw material and residual products is significantly reduced.
Sweden now imports all of the molybdenum that is used, maily in the production of high-performance, stainless and tool steels. However, the original raw material, molybdenum sulphide, is available in certain copper deposits, even in Sweden.
"In the long run, the development of a cost-effective and climate-neutral process for hydrogen reduction of molybdenum oxide would mean self-sufficiency for molybdenum in Sweden," says project manager Lars-Olov Nordberg.
The results of the project, which is funded via Vinnova, will be presented before the end of September.
/Photo/ Towa Eriksson, Uppsala University and Lars-Olov Nordberg, Swerim with the test rig, where trials are being conducted under controlled conditions.