Utilisation of waste incineration bottom ash

Denmark can be considered one of the leading countries in terms of processing and using bottom ash from waste incineration plants with energy utilisation, with a legal framework that protects the environment against unacceptable  impacts, and a processing technology and logistics that ensure that the treated bottom ash reaches a quality that allows it to replace raw materials such as natural gravel from gravel pits.

As part of the bottom ash processing, significant amounts of metals are also recovered from the bottom ash.

Since 2020, the regulatory basis for the utilisation of bottom  ash from Danish waste-to-energy plants has re-ceived a renewed focus, partly due to the recent European dialogue on the classification of the mineral residual products, including bottom ash.

Unfortunately, the regulatory and operational practice of management of bottom ash, which has been developed over many years in Denmark, has not been adequately described in any recent publications.

On behalf of the Danish Waste Association, Danish Waste Solutions ApS has with input from the industry (AFATEK A/S) prepared a paper that describes the experience, conditions and current practice for utilisation of bottom ash from municipal solid waste incineration plants as part of the circular economy.

The paper is expected to be used by the waste industry and purchasers of “bottom ash gravel”, but also as general information material for a wider public.