From waste to raw material: the circular power of IBA
Every year, millions of tonnes of waste are treated in Waste-to-Energy (WtE) plants in the Netherlands. In addition to sustainable heat and electricity, this process also produces a valuable residual material: incinerator bottom ash (IBA). From the 1.8 million tonnes of IBA that remain, modern processing companies such as HEROS Sluiskil recover around 105,000 tonnes of iron, 25,000 tonnes of aluminum, and 10,000 tonnes of copper every year. This corresponds to 13,125 km of guard rails, 1.67 billion soft drink cans, and the copper requirement for 333,000 battery packs for electric cars.
The remaining mineral content of IBA —1.4 million tonnes per year—is reused as a secondary construction material, serving as a sustainable alternative to sand and gravel in concrete products, as a foundation for industrial plants, and as a building material for roads. This puts the Netherlands at the forefront in Europe and demonstrates how the circular reuse of metals and minerals from MV slag is possible on a large scale.
“Due to inconsistent government policy, the Netherlands is losing its leading position in the recycling of incinerator bottom ash.”
HEROS Sluiskil as an example of a threatened success story
As the largest IBA processing company in the Netherlands, HEROS Sluiskil processes 1.3 million tonnes of bottom ash annually. Seven of the 12 Dutch waste incineration plants rely on the infrastructure provided by HEROS. The 55-hectare Terneuzen Eco Park is a global example of innovation in slag processing.
Two years ago, HEROS’ shareholder approved investments of €110 million for further modernisation and expansion of the facilities, including a new washing plant for 600,000 tons of IBA per year. However, the current political turmoil has put these plans on hold, with far-reaching consequences for Dutch ambitions in the field of circular economy.
Washing is not a panacea
Although mandatory cleaning of IBA is presented as a solution, the practice is rather contradictory. The quality of WtE bottom ash varies between waste incineration plants and deteriorates with changing waste streams. Therefore, there is no guarantee that washed IBA is always safe and clean. Incidents involving washed IBA underscore this and have severely affected market acceptance.
In addition, washing not only incurs considerable costs, but also creates a new waste stream: hundreds of thousands of tonnes of contaminated sludge from the process have to be sent to landfill – despite the fact that there is a moratorium on landfilling. Furthermore, it is impossible to increase the required washing capacity within two years.
What needs to be done?
To prevent the Netherlands from losing its leading position in the circular economy, realistic and consistent policies are urgently needed. HEROS therefore calls on the government to take action:
Adopting a flexible policy that supports selective washing rather than an all-or-nothing approach.
Retention of existing applications in concrete and foundations to ensure continuity.
Providing realistic transition periods for the development of new technologies and market demand.
Adopting coherent national strategies that prevent local governments from unnecessarily banning secondary construction materials.
Creating investment security so that sustainability projects such as the planned HEROS car wash can finally be realised.
The Netherlands has the opportunity to remain the European leader in IBA recycling. HEROS calls for vision and determination to correct the current political plans.
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