Landfilling remains the primary disposal method, but is increasing in technical structures

The data monitoring was carried out on the basis of an industry-specific questionnaire from the ITAD and BMKE associations for the 2024 reporting year and covers all 39 slag processing plants in Germany known to the associations. The survey on relevant key data in the field of slag processing covered both mineral material flows and metals.

Dr Ragnar Warnecke, Chairman of the Board at ITAD, is delighted with the contribution that grate ash processing makes to the circular economy and climate protection: “Grate ash represents a reliable source of raw materials for the production of scrap metal, and metal recycling remains, as in the past, at a high level, making a significant contribution to avoiding emissions from metal production using primary raw materials. With regard to the utilisation of the mineral fraction, we are working together with other associations to ensure that new fields of application are opened up in which grate ash can be used to produce safe secondary building materials, thereby contributing to the expansion of the circular economy. As our forthcoming Roadmap 2045 also shows, the resource potential of grate ash will remain at a similar level in the foreseeable future. We therefore expect the legislator to tap into this potential by creating suitable framework conditions, based on the findings of numerous research projects.”

Once again, a key driver behind the joint initiative by the associations was the importance of promoting the recycling of incinerator bottom ash (IBA) in civil engineering structures. Not least against the backdrop of the entry into force of the Substitute Building Materials Ordinance (ErsatzbaustoffV), it was particularly important to highlight the recycling rates in the first full year under the "new" regulatory framework. A comparison of the figures for 2022 and 2024 clearly shows that the recovery of IBA in civil engineering structures has risen from around 13 % to around 25 %. However, recovery and disposal in landfills still account for over 70 %, making it by far the largest disposal route for IBA.

Rebecca Winkler, Chair of the Incinerator Bottom Ash Specialist Group and Deputy Chair of the BMKE, explains: “The figures from 2024 show that the use of IBA in civil engineering structures has increased under the Substitute Building Materials Ordinance. An increased demand for IBA, particularly among private users, can be observed. Unfortunately, we cannot observe this positive trend among public sector clients. It therefore remains necessary to further strengthen the public sector’s obligations regarding the prioritisation of recycled materials. The consistently high levels of recycling and disposal in landfills highlight the significant potential for higher-value recycling of IBA.”