Heidelberg Materials has commissioned an innovative recycling plant for selective separation at its production site near Katowice, Poland. The first-of-its-kind facility features a proprietary crushing mechanism that enables sophisticated separation and sorting capabilities to fully recycle demolition concrete and substitute virgin materials in concrete production. With a capacity of up to 100tph of concrete, Heidelberg Materials is the first company in the industry to introduce high-quality, selective concrete separation at this scale.
As part of the company’s patented ReConcrete process, demolition concrete is broken down into its original constituents through a newly-designed, proprietary crushing mechanism. The fractions obtained include sand and gravel of the highest quality, equivalent to the one of virgin raw materials. Recycled concrete paste (RCP) is the finest fraction of the separation process. RCP can be either used as an alternative raw material for clinker production replacing limestone and reducing CO2 emissions or as a secondary cementitious material.
In addition, RCP can act as a carbon sink, absorbing and permanently binding CO2 over the entire lifespan of an infrastructure or building project. To make use of this potential and initiate what is known as “enforced carbonation”, the RCP can also be exposed to raw exhaust gases from cement production. The resulting carbonated RCP (cRCP) has the potential to mineralise about 150kg CO2 per tonne of RCP, significantly reducing CO2 process emissions caused by carbon-intensive clinker production. At the same time, the cRCP can be used as a low-carbon cementitious material by reducing the amount of clinker necessary.
To further explore this technology, Heidelberg Materials is currently building an industrial pilot facility for enforced carbonation at its cement plant in Górazdze, Poland. The RCP obtained at the recycling plant near Katowice will be transported to the pilot facility in Górazdze, where it will be exposed to the exhaust gases from the kiln. Mechanical completion of the facility is expected by the end of 2024.
