Technological breakthrough towards recycling industrial waste

"We have finally had verification from external experts that we are producing a mineral mass that does not have environmentally hazardous properties. This is a homogeneous mass that we hope and believe can be used for something useful," says the CEO of NOAH Solutions, which operates the reception and processing plant at Langøya, Tove Stuhr Sjøblom.

Two independent reports, from Swedish Kemakta and Danish Waste Solutions respectively, state that the dewatered pulp produced by NOAH on Langøya clearly falls within the criteria for so-called ordinary waste, that is, a fraction that requires special follow-up, but does not contain hazardous substances.

Large volumes

Stuhr Sjøblom characterizes the conclusions as a significant technological breakthrough in the part of the industry that handles inorganic masses, and which opens up many new opportunities for better utilization of society's resources.
"This is groundbreaking also because we are talking about such large volumes. This is circular economy on a scale that really pays off," says Stuhr Sjøblom, referring to the fact that NOAH produces several hundred thousand tons of mineral pulp per year. Langøya outside Holmestrand per year.
She emphasizes that further work remains to secure the flows and commercialize the use of the mineral mass. Among other things, work remains to sift out the fractions that fall outside the requirements specifications.

Long-term work

The change in classification from hazardous waste to ordinary waste has been going on in different phases for over six years. Max lab IV, belonging to Lund University, has examined the mineral mass in a large synchrotron, and in addition, extensive biotests (ecotoxic tests) have been carried out by an external lab. The conclusion is clear: After treatment at Langøya the mineral mass no longer has hazardous properties. This conclusion was strengthened by two different independent third-party assessments carried out by the Swedish Kemakta and by Danish Waste Solutions. The report from Kemakta is attached, together with a summary in Danish.

"Based on this, and our own analyses over many years, we are now completely confident that our product on Langøya is ordinary waste according to the European regulations for classification. We are also close to the next category in the hierarchy, inert waste, which has an even smaller environmental impact. We are working on further verifying the results by testing the fraction in specific construction or restoration projects. To a large extent, it is about getting the authorities to do their tests and investigations. This is necessary in order to be able to increase the area of ​​use of the mineral mass, "explains senior technologist at NOAH Inge Johansson.

Improvements and collaboration

The breakthrough has come as a result of adjustments and improvements in the process, good cooperation with waste producers and an increased understanding of the chemical composition of the product. The main components in the reception are fly ash from incineration plants and dilute acid from industry. In the process, these input factors neutralize each other chemically so that the heavy metals are bound and do not escape. Through a carefully tested process and dewatering, NOAH obtains a mineral mass, a silt fraction, which is well within the requirements for ordinary waste, i.e. waste without hazardous properties.

The mineral mass is well suited for landscape restoration. The ambition going forward is to find good uses that meet needs in society.
"Now that we have documented that our mineral mass no longer has hazardous properties, it opens up opportunities to use it for, for example, landscape rehabilitation, landfill sealing layers or for cleaning other waste fractions," says Inge Johansson, who is one of Scandinavia's leading experts on fly ash from waste incineration.

Large circular step

For NOAH as a group, the news is taken from Langøya very well received. The company has high ambitions when it comes to researching and developing new, forward-looking solutions.

"This change in classification is a major milestone for us, our customers and our partners. Together, we are helping to take Norway on a big and right step towards becoming more circular and making better use of unused resources in society. The next time you throw something in the residual waste at home, you can think about the fact that that garbage bag is first turned into heat and electricity, and some of it becomes fly ash, which then comes to us, is treated - as well as treating residual acid from industry, and is then converted into Langøya to new building materials. We would not have achieved these improvements without the good cooperation with the incineration plants, academia and the industry in general, says CEO of NOAH Anders Lægreid.