A great deal of the plastic in end-of-life products cannot currently be recycled. Research conducted by Vinnova, Boliden and Stena Recycling has reduced the amount of plastic being sent to landfill sites or waste incinerators. Instead, it can now be used to fire smelting furnaces and replace fossil fuels, such as coal.
Each year, Sweden generates around 300,000 tonnes of plastic waste that cannot be recycled cost effectively, due to its complex composition or because it contains other materials. Much of it is production waste or comes from end-of-life electronic products and cable. While it is possible to recover the energy from most of it, some is still sent for landfill.
– This presents a major challenge and we must find sustainable ways to recycle as much plastic as possible, says Marianne Gyllenhammar, a project manager in Stena's Research and Development department.
A research project, funded by Vinnova, recently tested a solution to this problem. Boliden, the Swedish mining and metal smelting company, also took part in the research. The project tested the use of plastic as a reducing agent (as a replacement for coke) in the recovery of zinc from slag at Boliden’s Rönnskär facility.
This technique proved effective in full-scale trials, which means that some problematic plastics can now be used to generate energy and replace fossil fuels. Metals, mixed in the plastic waste, can also be extracted and recycled as part of the process, which would otherwise be lost.
This is a win-win situation for all parties - manufacturers, consumers, recyclers and businesses like Boliden. By working together, manufacturing and recycling companies can move material up the waste hierarchy and reduce fossil fuel consumption by finding climate-smart alternatives. The potential benefits are so great that if Boliden invested in the process at one smelting furnace, it could reduce its coke consumption by 10,000 tonnes per year.