Sorting as a game-changer in construction material recycling
The future of construction material recycling depends above all on the quality of the recovered raw materials and resources. This is precisely where sorting takes on enormous importance: It creates the conditions necessary to selectively separate valuable mineral components from one another and produce high-quality secondary raw materials. A Swiss flagship project demonstrates the potential this key technology already offers today.
Europe’s largest waste stream is full of untapped opportunities: construction and demolition waste could make a significant contribution to the raw material supply for the circular economy – yet in many places, its potential is still far from being fully realized. While crushing, screening, and washing have long been standard practices in many facilities, sensor-based sorting is what makes the decisive difference: It precisely separates valuable material streams from one another and noticeably improves the quality of recycled building materials.
BRT Baustoff Recycling Thurgau AG in Switzerland demonstrates how this key technology creates added value in practice. The company is regarded as a highly competent partner and a pioneer in the mineral recycling industry and relies on several processing machines from Binder+Co – including, in particular, two CLARITY sorting systems that perform a crucial quality control step at the end of the process.
Processing to primary material standard possible
“We primarily process excavated material that is chemically contaminated or mixed with construction debris,” explains Martin Feldmann, Managing Director of BRT AG. Despite this, the company still manages to return approximately 75 % of the processed material to the material cycle as sand and gravel.
The process begins right at the material intake stage. Depending on its origin and contamination level, the delivered excavated material is evaluated, consolidated into different storage areas, and then uniformly fed into the wet mechanical processing line. There, it is washed, crushed, and separated into different particle sizes. Only then does the step follow that is increasingly becoming the decisive factor for success in the processing of construction waste: Binder+Co’s CLARITY systems use high-resolution cameras and intelligent image analysis to detect even the slightest color differences and material characteristics. “Thanks in large part to optical sorting, we can now recirculate the processed material as primary gravel,” emphasizes Feldmann. Broken bricks are also reliably separated from high-quality gravel, foreign materials are removed, and product quality is significantly improved.
The benefits of this sorting process extend far beyond the plant itself. The majority of the sorted sand and gravel flows directly into concrete production at the adjacent concrete plant – only a small portion is marketed separately as a loose component. Even the separated broken bricks are put to use, for example as an aggregate for roof substrates or in non-standard concrete mixes. The purity of the materials is always crucial here, because only high-quality secondary raw materials find lasting acceptance in the market.
Artificial Intelligence as the next step
Switzerland is considered to be particularly strictly regulated when it comes to handling construction waste. The Ordinance on Waste Prevention and Disposal (VVEA) distinguishes five contamination levels for excavated and demolished material – ranging from uncontaminated to heavily contaminated. Building material recycling plants play a crucial role in this context. It is precisely in this demanding environment that BRT Baustoff Recycling Thurgau AG has established itself.
The wet mechanical processing plant has been in operation since 2023 – equipped with several screening and sorting machines from Binder+Co. “Now, every metric ton processed by us no longer ends up in a landfill but is returned to the construction materials market,” says Feldmann, summarizing the approach. At the same time, he sees the industry facing new challenges. Composite materials and rising quality requirements will demand even more efficient processing methods in the future. That is why it is important to continuously evaluate new technologies and implement them where they create added value.
So far, the CLARITY system has primarily sorted by color. Thanks to AI support, however, black materials – such as asphalt and slag – will also be reliably separated from black gravel in the future. “We are very interested in the latest AI upgrade so that we can remove the remaining contaminants in the form of slag and surface material, and also to further increase the performance of the other fractions,” says Feldmann. The demands on recycled building materials continue to rise, and with them the importance of high-performance sorting technologies.
Optical sorting as a game-changer in construction material recycling
Binder+Co sees sorting as the next step in the development of construction material recycling, particularly in light of growing resource shortages of gravel and sand, as well as the goal of reducing CO2 emissions. “Crushing, screening, and washing are state-of-the-art today. However, it is only through sorting that optimal and consistent recycling of mineral building materials becomes possible,” explains Manfred Berghofer, sales representative for sorting technology, minerals, and construction waste at Binder+Co. Given the increasing scarcity of primary raw materials, rising landfill costs, and increasingly stringent legal requirements, sorting will play a key role in the future.
Regulatory pressure is also likely to increase: Berghofer expects EU rules on construction waste recycling to become stricter in the near future – similar to the already stringent Swiss regulations. Companies that are already relying on effective sorting today will be prepared for this. “Only the precise separation of materials creates the quality that turns construction waste back into a sought-after raw material,” says Berghofer. “Sorting will thus become the real game-changer in the mineral circular economy, and companies like BRT are demonstrating that this is already possible today.”
