million tonnes of bottom ash are produced every year in Germany from
incinerating municipal solid waste that contain around ten percent metal. So
far, it is only possible to recover this metal from the proportion of ash that
has a grain size of more than three millimeters. The smaller-grained fine ash
is often removed in advance by sieving and then dumped which means that the
valuable materials it contains are lost.
project partners are developing and constructing an industrial plant able to
process even the smallest particles. The quality of the recovered metals should
be same as the respective primary metals. Another focus of the project is on
recovering the minerals that make up more than three quarters of municipal
solid waste ash.
preceding project, a technology was already developed and tested on a pilot
scale. This was able to double the volume of non-ferrous metals recovered from municipal
solid waste bottom ash. Germany-wide, this means it would be possible to recover
27,000 tonnes of non-ferrous metals each year from 5.4 million tonnes of
municipal solid waste bottom ash. In this follow-up project, the partners from
industry and science are now further developing the technology for use on an
industrial scale. In “STRATEGO”, two companies, H-U-R Hamburg GmbH
Hamburger-Umwelt-Recyclingtechnologien (as project coordinator) and C.C. Umwelt
AG from Krefeld, are working together with the Institute of Environmental
Technology and Energy Economics – Waste Resources Management at the Hamburg
University of Technology.
of the innovation is the high-speed impact crushing of ash particles at a speed
of up to 1,280 kilometers per hour. The impact blasts the metals free and makes
them accessible for recycling. As well as optimizing this technology,
“STRATEGO” wants to make the framework conditions for the plant more efficient,
including operating the plant entirely with renewable energy and creating
closed loops within ash processing.