Ankara Hub for Circularity

The Turkish demonstration within United Circles is centred on the Ankara Hub for Circularity, where construction and demolition waste will be transformed into new construction materials. Its primary objective is to recover the different materials generated through the demolition of a building to the greatest extent possible and reuse them within the same value chain in the construction of a new building.

Construction and demolition waste is highly heterogeneous. Concrete, cement paste, natural stone, bricks, ceramics, wood, metals, plastics and insulation materials are frequently found mixed together. Coarse mechanical separation methods alone may not be sufficient to achieve the purity and quality levels required by downstream production processes.

The success of the Ankara value chain therefore depends on preparing the waste correctly, reliably identifying the materials it contains and directing each fraction to the appropriate production process. Minomad’s principal responsibility within the project is to develop this critical sorting infrastructure.

Minomad’s Intelligent Sorting Solution

The solution being developed by Minomad is based on an integrated process approach that combines mechanical material preparation, liberation, surface cleaning, sensor-based material identification, automated classification and sorting.

Construction and demolition waste will first undergo controlled mechanical processing to obtain the particle size distribution and surface characteristics required for sensor-based sorting. Rotary crushing and attrition-based preparation stages will facilitate the liberation of interconnected materials, the removal of cement paste from concrete surfaces and the creation of a more consistent feed stream for reliable sensor performance.

The prepared material will then be fed into an X-ray Transmission (XRT)-driven multi-sensor sorting system. XRT technology identifies materials based on differences in X-ray attenuation and density, enabling the separation of particles that may appear similar externally but have different internal structures. This allows materials such as concrete, natural stone, bricks, ceramics, wood and metals to be classified without relying solely on colour or surface appearance.

In addition to XRT, the proposed system architecture will incorporate complementary sensing technologies. X-ray Fluorescence (XRF) will support the determination of the elemental composition of materials, while Near-Infrared (NIR) and hyperspectral imaging technologies will contribute to the identification of polymers, wood and other organic components based on their spectral characteristics.

The combined evaluation of data obtained from different sensors will enable more precise material classification and allow sorting parameters to be optimised in response to variations in waste composition. Through Minomad’s integrated system solution, the project aims to achieve a sorting performance exceeding 90% and produce cleaner, more consistent and traceable secondary raw materials for downstream production processes.

Recycled Aggregate and Cementitious Raw Material from Waste Concrete

One of the principal outputs of the system being developed by Minomad is the separation of waste concrete into recycled aggregate and fractions rich in hydrated cement paste (HCP).

Following the appropriate quality-control procedures, the recovered aggregate may be reused in the manufacture of new construction materials. The HCP-rich fraction will be directed to an accelerated carbonation process. During this process, CO₂ will be chemically bound within the mineral structure of the cement paste, while a new raw material suitable for use in low-carbon cement production will be obtained.

This approach will enable the residual cementitious content of the waste to be recovered while also reducing the demand for virgin aggregate and newly produced clinker. It will therefore contribute to lowering the energy consumption and carbon emissions associated with both primary raw-material extraction and high-temperature clinker production.

The other separated materials will likewise be directed to upcycling processes suited to their individual characteristics. Waste wood will be used in the manufacture of cement-bonded particleboards, while polyurethane-based insulation materials will be processed through advanced recycling technologies to produce new insulation products.

The resulting low-carbon cement, recycled boards and insulation products will be brought together in the two-storey, 3D-printed demonstration building to be constructed in Ankara. This full-scale application will demonstrate how materials recovered from the demolition of one building can become essential inputs for the construction of another.

Applying Mineral Processing Expertise to the Circular Economy

Within United Circles, Minomad is transferring its expertise in material characterisation, liberation, process design and sensor-based sorting from the field of mineral processing to the construction and demolition waste sector.

The system is designed not merely to separate waste into broad categories such as concrete, wood, metals or plastics, but to transform each material into a secondary raw material that meets the quality requirements of its intended downstream process. Minomad’s solution therefore establishes a technical bridge between waste management and the production of cement, aggregates, engineered wood products and insulation materials.

The approach developed through the project is expected to reduce the amount of construction and demolition waste sent to landfill, facilitate the recovery of existing waste stockpiles and earthquake debris, and decrease demand for natural aggregates, cement raw materials and other primary resources.

The system is also intended to evolve into a scalable and traceable model that can be implemented by municipalities, recycling facilities and construction-material manufacturers. In this way, the technology and implementation model developed in Ankara may serve as a reference for other cities and industrial regions facing similar waste-management challenges.

United Circles has received funding from the European Union’s Horizon Europe programme under Grant Agreement No. 101178798.