On the clean and efficient thermal treatment of de-inking solid residues

Authors

  • Janusz A. Kozinski,

    Corresponding author
    1. McGill University, McGill Metals Processing Centre, Department of Mining & Metallurgical Engineering, 3450 University St, FDA 119, Montreal, QC, Canada H3A 2A7
    • McGill University, McGill Metals Processing Centre, Department of Mining & Metallurgical Engineering, 3450 University St, FDA 119, Montreal, QC, Canada H3A 2A7
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  • Guohui Zheng,

    1. McGill University, McGill Metals Processing Centre, Department of Mining & Metallurgical Engineering, 3450 University St, FDA 119, Montreal, QC, Canada H3A 2A7
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  • Raafat Saade,

    1. McGill University, McGill Metals Processing Centre, Department of Mining & Metallurgical Engineering, 3450 University St, FDA 119, Montreal, QC, Canada H3A 2A7
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  • Sergio Di Lalla

    1. McGill University, McGill Metals Processing Centre, Department of Mining & Metallurgical Engineering, 3450 University St, FDA 119, Montreal, QC, Canada H3A 2A7
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Abstract

Thermal treatment of contaminated de-inking sludge in a low-high-low (LHL) temperature reactor was investigated. Experiments were conducted in a Cahn TGA-171 furnace coupled with a Mattson Galaxy 5020 FTIR. Sludge samples (70 g) were heated up to 1770 K (50 K/min.), kept at that temperature for 5 min. and were then quenched (60 K/min.). During the LHL process the sludge underwent structural transformations from a mixture of fibers, through skeleton-like structures (45–110 μm), porous particles, to compact spheres (5–30 μm). It was shown that the LHL treatment results in a safe encapsulation of heavy metals (Pb, Cd) inside the ash and in a 78.2% decrease in the amount of mutagenic polycyclic aromatic hydrocarbons. The LHL method developed could help to solve waste management and environmental protection problems.

Abstract

On a étudié le traitement thermique d'une boue désencrée contaminée dans un réacteur à température basse-élevée-basse (LHL). Les expériences ont été menées dans un four Cahn TGA-\1\ couplé à un FTIR Mattson Galaxy 5020. Des échantillons de boue (70 g) ont été chauffés jusqu'à 1770 K (50 K/min), gardés à cette température pendant 5 minutes, puis trempés (60 K/min). Pendant le processus LHL, la boue subit des transformations structurelles, évoluant d'un mélange de fibres, vers des structures squelettiformes (45-110 um), des particules poreuses, puis des sphères compactes (5-30 um). On montre que le traitement LHL permet une encapsulation s-re des métaux lourds (Pb, Cd) dans la cendre ainsi qu'une diminution de 78,2% de la quantité d'hydrocarbures aromatiques polycycliques mutagènes. La méthode LHL peut servir à résoudre les problèmes de gestion des déchets et de protection de l'environnement.

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