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Interactions between waste paper sludge ashes and superplasticizers based on polycarboxylates

  • In many industrial nations, about two third of the paper demand is covered by recovered paper. A major process step within the treatment of waste paper is the de-inking. It is a floating process yielding paper sludge as a waste product. About 50 % of this residue is used as a fuel. In several cases it is burnt at temperature of about 850 °C and thereafter the accrued ashes are collected in the flue gas filter. During the combustion, kaolinite and calcium oxide generate gehlenite and larnite. Calcite is the main component of waste paper sludge ash (PA).The chemical and mineralogical composition of PA suggests using it as a supplementary cementitious material. In modern construction materials technology, workability aspects gain importance, since for most modern materials the rheology and compaction ability are relevant for the operation at a hardened state. It was observed that PA significantly increases the water demand of powder systems, which can cause serious problems during theIn many industrial nations, about two third of the paper demand is covered by recovered paper. A major process step within the treatment of waste paper is the de-inking. It is a floating process yielding paper sludge as a waste product. About 50 % of this residue is used as a fuel. In several cases it is burnt at temperature of about 850 °C and thereafter the accrued ashes are collected in the flue gas filter. During the combustion, kaolinite and calcium oxide generate gehlenite and larnite. Calcite is the main component of waste paper sludge ash (PA).The chemical and mineralogical composition of PA suggests using it as a supplementary cementitious material. In modern construction materials technology, workability aspects gain importance, since for most modern materials the rheology and compaction ability are relevant for the operation at a hardened state. It was observed that PA significantly increases the water demand of powder systems, which can cause serious problems during the casting of mineral binder systems containing PA. It is therefore obvious that binder systems containing PA might demand for the use of superplasticizers. Superplasticizers are polymers with anionic backbone that cause electrostatic and steric repulsion effects upon adsorption on surfaces of particles and hydration phases. In this paper interactions between superplasticizers and waste paper sludge ashes are discussed and analysed. Based on observations of changes in the zeta potential and the dispersion of the particle system, the influence of the charge density of superplasticizers is observed and time dependent effects are demonstrated.zeige mehrzeige weniger

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Metadaten
Autoren/innen:Maria Barthel, Wolfram Schmidt, Hans-Carsten Kühne, Katrin Rübner
Persönliche Herausgeber/innen:Wolfram Schmidt, Nsesheye Susan Msinjili
Dokumenttyp:Beitrag zu einem Tagungsband
Veröffentlichungsform:Eigenverlag BAM
Sprache:Englisch
Titel des übergeordneten Werkes (Englisch):Advances in Cement and Concrete Technology in Africa
Jahr der Erstveröffentlichung:2016
Organisationseinheit der BAM:7 Bauwerkssicherheit
7 Bauwerkssicherheit / 7.4 Baustofftechnologie
Herausgeber (Institution):BAM
Verlag:Bundesanstalt für Materialforschung und -prüfung (BAM)
Verlagsort:Berlin
Erste Seite:181
Letzte Seite:186
DDC-Klassifikation:Naturwissenschaften und Mathematik / Chemie / Analytische Chemie
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Sanitär- und Kommunaltechnik; Umwelttechnik
Freie Schlagwörter:Cement; Concrete; Polycarboxylate ether; Rheology; Waste paper sludge
Themenfelder/Aktivitätsfelder der BAM:Umwelt
Umwelt / Ressourcenrückgewinnung und Materialverwertung
Analytical Sciences
Analytical Sciences / Oberflächen- und Grenzflächenanalytik
Veranstaltung:2nd International Conference on Advances in Cement and Concrete Technology in Africa
Veranstaltungsort:Dar es Salaam, Tanzania
Beginndatum der Veranstaltung:27.01.2016
Enddatum der Veranstaltung:29.01.2016
ISBN:978-3-9817502-3-2
Verfügbarkeit des Volltexts:Volltext-PDF im Netzwerk der BAM verfügbar ("Closed Access")
Datum der Freischaltung:18.07.2016
Referierte Publikation:Nein