2021/09/15 Press release

First Swedish plant with large-scale water treatment using by-products from the steel industry

Slag from steel industry production is now replacing macadam as a material in the treatment of industrial storm- and wastewater. The first large-scale use for treating stormwater will be in an industrial plant inaugurated 13 September in Västerås, Sweden.

Björn Haase, Manager Non Metal Products in Sweden, Höganäs and Catharina Lindgren, CEO, Carbomax. Photo: Adam af Ekenstam

Polluted stormwater is a major environmental problem and can affect natural ecosystems and pollute water sources for our water treatment plants. Macadam has mainly been used for treating surface water to date. A material involving blasting rock, which is then transported and crushed.

Petrit® E is now available – a new circular alternative made from slag, a by-product from iron and steel industry production. Sweden’s first facility was inaugurated yesterday with large-scale use of the product for surface water treatment.

It involves Carbomax’s 10,000 square meter storage facility for coal products and alloys, where Petrit E is placed as delay magazines in ditches for effective drainage and purification of storm water. Particles from carbon dust and other substances are absorbed by the new material.

From residual product to environmental benefit

“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,” says Björn Haase, responsible for by-products products at Höganäs, the supplier.

The idea of purifying water with slag was born more than ten years ago and was also presented at the UN’s ocean conference in New York in 2017. It has been further developed via field trials in the Vinnova-funded research project Minrent. The idea now becomes a reality on a large scale at Carbomax in Västerås.

"We hope this partnership can inspire more circular innovation in the iron and steel industry. It shows that it is possible to help a customer turn a by-product into a saleable product, and to make our industry more sustainable, while reducing impact on the environment and natural resources," says Catharina Lindgren, CEO of Carbomax.

Press photos for free publication can be downloaded in our image gallery, please specify: Photo: Adam af Ekenstam

For more information, please contact

Björn Haase, Manager Non Metal Products in Sweden, Höganäs, +46 (0)70-656 44 30, bjorn.haase@hoganas.com

Catharina Lindgren, CEO, Carbomax AB, +46 (0)70-563 18 02, catharina.lindgren@carbomax.se



Facts Sweden’s first large-scale water treatment plant using Petrit E

Owner: Carbomax AB, which built the plant for storage of carbon products and alloys.

Product supplier, Petrit E: Höganäs Sweden AB

Landowner: The area is leased in cooperation with Mälarhamnar through long-term agreements with the City of Västerås.

Earthworks and civil engineering works: PEAB (prime contract).

Environmental approval: City of Västerås (Environmental and Health Administration). Surface water recipient Mälarenergi AB has approved the process.

About Petrit E

Slag is important in order to control the melting process optimally and is produced to act as a protective film over the steel bath, and to bind and filter phosphorus and silicon, substances not desirable in the steel. 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.

About Carbomax

Carbomax was established in 1992 and is an expert in adapting coal and alloys for processes at steel mills and foundries. For a number of years, Carbomax has also been briquetting waste from the iron and steel industry for more efficient recycling of metals and reduced use of virgin raw materials. Turnover is approximately SEK 1,000 million per year. The company employs 30 people and supplies around 100,000 tonnes of raw materials annually to the metallurgical industry. carbomax.se

About Höganäs

Höganäs is a world leader in the market for metal powders with an annual capacity of 500,000 tonnes. In close cooperation with customers, Höganäs develops tomorrow’s solutions for automotive components, electrical motors, surface coating, additive manufacturing and sustainable treatments for water and soil. Höganäs has 18 production sites worldwide and 2,400 employees. Höganäs was founded in 1797, and is owned by the Lindéngruppen Group and by the Wallenberg-owned FAM.




Emma Lefdal
VP Corporate Communications