Recycled fertilisers from bioindustry
Swedish company EasyMining are recovering potassium and phosphorous from bioindustry ashes for heavy-metal-free fertilisers.
Potassium and phosphorus fertilisers are still largely produced from virgin mining, says EasyMining, and secondary sources, particularly by-products and waste from bioindustry, could supplement or replace conventional fertilisers.
The company says that while incineration can solve the biological and organic contamination of landfill disposal, and concentrates the contained nutrients, it does not remove the heavy metals.
'Presently, Canada, China, Russia and Belarus dominate the global potassium production and European Union countries are highly dependent on imports. It is high time, that we start developing processes to become self-reliant,' says Cristian Tunsu, Lab Manager and Senior R&D Engineer at EasyMining.
After evaluating 20 ash sources, the team identified those with the highest promise for sustainable fertiliser production. One source is bioindustry ashes, particularly from poultry litter, which EasyMining says offers a promising secondary source of critical nutrients.
'Poultry litter fly ash contains high concentrations of potassium, over 20wt.% elemental potassium, as well as phosphorus. However, heavy metals such as copper, zinc and magnesium are also present, so direct application on arable land is harmful to the environment, which makes our process even more important,' says Ehsan Moslehi, advanced R&D engineer and lead scientist for the project.
EasyMining claims to be able to extract potassium using water, separating it from phosphorous and heavy metals, which is concentrated into a solid undissolved fraction.
They say they can also recover pure phosphate fertilisers from the undissolved ash fraction, allowing for the recovery of high-purity calcium phosphate for feed or a fertiliser, while also obtaining the heavy metal as a separate fraction for safe disposal.
They are working on growth tests with the recycled fertilisers to validate their effectiveness and conduct a lifecycle assessment due in early 2026.
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