High value recycling of refractories into the production of new refractories is currently limited due to a shortage of high purity raw materials.
In current practice, at end-of-life different types of refractories are mixed resulting in material that is only suitable for low grade applications or landfilling. For high value reuse as refractory raw materials, the mixed refractory waste must be sorted into high purity fractions of distinct refractory types based on the chemical composition.
The ongoing European FP7 project REFRASORT aims to develop an automated sorting technology to separate up to 8 types of waste refractory bricks into pure material fractions under industrial conditions. The refractory types that are targeted represent > 90% of all shaped refractories, and fall into three main classes (magnesia-based, doloma-based, alumina-based) with further subdivisions based on C and Al content. The REFRASORT system consists of different steps, namely: 1) pre-treatment (dust and metal removal), 2) inlining, 3) identification and 4) mechanical sorting. This contribution focuses on the metal removal and identification steps.
As a result of the use and handling, a surface alteration layers is present on the spent refractory bricks. This layer, which is generally 100 - 200 μm thick but may reach up to 1 mm at surfaces that were in direct contact with the molten metal and slag, complicates the search for a suitable identification technique. Feasibility tests showed that most sensor techniques based on surface measurements, such as colour sensors, LIF, XRF and FTIR are not suited for reliable identification. The most promising technique for reliable identification of spent refractories was found to be the LIBS (Laser-induced breakdown spectroscopy), but it too experiences difficulties to identify metal and C containing bricks due to the inherent properties of the spent refractories. Feasibility tests with a portal-type metal detector have shown promising results to sort out metal and C containing bricks simultaneously. These results are presented in this paper.
Copyright: | © ANTS - Institut für anthropogene Stoffkreisläufe an der RWTH Aachen |
Quelle: | SBSC 2016 (Februar 2016) |
Seiten: | 8 |
Preis: | € 0,00 |
Autor: | Liesbeth Horckmans Henning Knapp Philippe Dierckx Cord Fricke-Begemann Dr. Joachim Makowe |
Artikel nach Login kostenfrei anzeigen | |
Artikel weiterempfehlen | |
Artikel nach Login kommentieren |
Hochlauf der Wasserstoffwirtschaft
© Lexxion Verlagsgesellschaft mbH (8/2024)
Überblick über und Diskussion der Maßnahmen zum beschleunigten Ausbau
der Wasserstoffinfrastruktur in Deutschland
Die innerstaatliche Umsetzung des Pariser Klimaschutzübereinkommens
- ein Rechtsvergleich
© Lexxion Verlagsgesellschaft mbH (8/2024)
Like all public international law treaties, the Paris Climate Accords rely on national law for their implementation. The success of the agreement therefore depends, to a large extent, on the stepstaken or not taken by national governments and legislators as well as on the instruments and mechanisms chosen for this task. Against this background, the present article compares different approaches to the implementation of the Paris Agreement, using court decisions as a means to assess their (legal) effectiveness.
Klimaschutzrecht und Erzeugung erneuerbarer Energien in der Schweiz
© Lexxion Verlagsgesellschaft mbH (8/2024)
Verschachtelte Gesetzgebung unter politischer Ungewissheit