Aggregate Cleaning via Carbonation Grinding
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Solution Overview
Problem
Current recycling methods for waste construction materials, such as concrete and mortar, are inefficient in completely removing cementitious and binder materials from aggregates, leading to compromised properties in new construction materials and limited reuse potential due to incomplete cleaning and inefficient sorting processes.
Innovation Solution
A method involving grinding waste construction materials in a semi-autogeneous mill or compressive grinder, potentially with the presence of carbon dioxide, to effectively separate cleaned aggregates from powdery materials, optimizing particle shape and reducing binder content, thereby enhancing the recycling efficiency and quality of aggregates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current crushing and sieving methods are used to recycle waste construction material, then the process is simple and quick, but the aggregates are not cleaned enough and still carry significant amounts of cementitious materials
Solution Approach 1:
The patent changes the fundamental parameter of the grinding process by introducing carbonation (chemical parameter) and using high-pressure fluid jets (physical parameter) to remove cementitious materials from aggregates. This transforms the simple mechanical crushing process into a multi-parameter process that achieves superior cleaning efficiency while managing complexity through integrated system design.
Solution Approach 2:
The patent uses carbonation as an intermediary chemical process that weakens the bond between cementitious materials and aggregates, making removal easier. The high-pressure fluid acts as an intermediary medium that delivers the cleaning action. These intermediaries enable effective cleaning without requiring excessively complex mechanical systems.
2Manufacturing precision
If sorting steps (manual or automated) are added to improve recycling quality, then aggregate cleaning improves, but additional time and cost are required
Solution Approach 1:
The patent performs preliminary carbonation treatment on the waste construction material before the main grinding and cleaning operations. This preliminary chemical treatment weakens the cementitious materials, making them easier to remove in subsequent steps, thereby reducing the time required for the main cleaning process and eliminating or reducing the need for separate sorting steps.
Solution Approach 2:
The patent integrates multiple functions (carbonation, grinding, and cleaning) into a continuous process flow without interruption. The material moves continuously through the system, with each stage preparing for the next, eliminating idle time between operations and removing the need for separate batch sorting steps.
3Reliability
If incomplete recycling is used to avoid property compromise in new construction materials, then structural integrity is maintained, but environmental sustainability and resource efficiency are reduced
Solution Approach 1:
The patent converts the previously harmful or problematic adhering cementitious materials into a benefit by using carbonation to selectively remove them, leaving clean aggregate surfaces. The carbonation process itself, which was once seen as just a chemical reaction, becomes a useful cleaning mechanism that improves aggregate quality and enables higher recycling rates while maintaining structural integrity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method achieves more efficient cleaning of aggregates, allowing for higher replacement levels in new construction materials and improved overall recycling process efficiency, with aggregates showing lower binder content and optimized particle characteristics.
Implementation Method 1
a method for the retrieval of aggregates from waste construction material, said method comprising a step of grinding the waste construction material
Implementation Method 2
grinding is done in a semi-autogeneous mill or on a compressive grinder
Implementation Method 3
WO 2014/154741 as well as WO 2014/040852 disclose processes for the recycling of construction waste. Therein, construction waste is carbonated and crushed to yield cleaned aggregates
Data Source
AI summary
Methods for the retrieval of aggregates from waste construction material by grinding in a ball mill or on a compressive grinder, which are useful in the recycling of waste construction material, especially in the recycling of concrete or mortar. Also, cleaned aggregates obtained from waste construction material by grinding and their use on the production of new construction materials.