21 May 2016

Mistra support for new battery-recycling process

Mistra is investing SEK 8 million to improve recycling of alkaline batteries. The project, which is being conducted by Swerea MEFOS, is one of six projects forming part of the second phase of the Mistra Closing the Loop research programme.

Swedish households are good at handing in spent batteries. Of 3,500 tonnes of alkaline batteries sold in 2013, some 2,400 tonnes — roughly 70% — was collected. This statistic places Sweden at the top of the EU league in terms of battery collection. Nonetheless, it does not suffice for a large-scale recycling plant. In the Environmental Battery Recycling project, the aim is therefore to create a simple, low-cost recycling process adapted for small and medium-sized companies, says Guozhu Ye, project leader and researcher at Swerea MEFOS in Luleå.

‘The ambition of the project is to bridge the gap between battery collection and the needs of the metallurgical industry, which are on a larger scale,’ says Guozhu Ye.

The project is based on an idea of vaporising the various metals in batteries, in a controlled and selective way, in a special reactor. The process will be optimised in a laboratory but also tested on a pilot scale at Swerea MEFOS. Material recycled in the project will also be shipped to the various industrial business partners for full-scale testing.

Broader process for recycling

One challenge posed by the project will be to recycle not only zinc but also the manganese content of the batteries, which currently ends up in landfill. Another challenge will be to dispose of the undesired contaminants contained in the batteries.

‘Mercury is relatively easy to separate. One key scientific challenge will be to learn how to optimise the process for removing cadmium,’ says Guozhu Ye.

The plan is for the zinc and manganese recycled in the process to be used in the production of new batteries, in a closed material flow. If the project is successful, the process will result in 80% of the material in the batteries collected being recycled. This is considerably better than the 50% recycling efficiency rate adopted as a target in the EU Battery Directive.

Previous Mistra research

Besides Swerea MEFOS, the project also involves a variety of companies, including the Swedish zinc producer Boliden, the Finnish battery-recycling firm Isologistics and the French Eramet, a leading manufacturer of EMD (electrolytic manganese dioxide), the key raw material for alkaline batteries.

Guozhu Ye has previous experience of two projects supported by Mistra. He headed the ViLD (vanadium in LD slag) project, which was part of the Steel Eco-cycle research programme (2004–12). In ViLD, a new method of recovering vanadium out of slag from steelworks was devised — a method currently being commercialised by a Finnish company.

‘We learnt a great deal in Steel Eco-cycle from doing applied work with industrial business partners. And we’re working in a similar way in this project.’

Guozhu Ye is delighted to be receiving support from Mistra again: ‘Mistra is one of the best funders of recycling research projects, with a superb international evaluation panel.’

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