Polluted stormwater is a major environmental problem and can affect natural ecosystems and pollute water sources for our water treatment plants. Up ‘til now most industries have been using macadam or other virgin materials for treating surface water, a material involving blasting rock, which is then transported and crushed. Introducing Petrit® E.
Höganäs was presenting the idea at the UN
The idea of purifying water with slag – a by-product from iron and steel industry production – was born more than ten years ago by Höganäs. We were even asked to hold a presentation on it at the UN Ocean Conference in New York 2017. Since then it has been further developed via field trials in the Vinnova-funded research project Minrent. And in September 2021, the first large-scale use of Petrit® E for treating stormwater was a fact.
“We’re actually turning a by-product into a material with environmental values and are currently starting to scale up the application for industrial water treatment.”
– Björn Haase, responsible for by-products at Höganäs
To make this happen, we have worked closely with our client Höganäs, the world leading manufacturer of metal powders for powder metallurgy. Of the slag that Höganäs manufactures annually, 15,000-16,000 tonnes is Petrit® E. In order for the material to be extra mineral-rich and have a gravel-like consistency, the ratio between calcium and silicon is adjusted.
The finished product is a material that can be densely compacted, and is also suitable for production of asphalt, aggregate in concrete and in stone wool production. We placed it as delay magazines in the ditches of our 10,000 square meter storage facility in Västerås. That way it drains and purifies the storm water in an exceptionally effective way.