Influence of ZnO on the activation of kaolinite-based coal waste: Pozzolanic activity and mineralogy in the pozzolan/lime system
| Autor: | Rosario García-Giménez, Moisés Frías, R. Vigil de la Villa, Lucía Fernández-Carrasco, Sagrario Martínez-Ramírez |
|---|---|
| Přispěvatelé: | UAM. Departamento de Geología y Geoquímica, Ministerio de Economía y Competitividad (España), European Commission, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LiTA - Laboratori d'Innovació i Tecnologia en l'Arquitectura |
| Rok vydání: | 2018 |
| Předmět: |
Coal wastes
LDH Aluminate Cement 020101 civil engineering 02 engineering and technology engineering.material C-S-H gels 0201 civil engineering Amorphous materials chemistry.chemical_compound Coal waste Geochemistry and Petrology Cement--Additives Kaolinite Geología Pozzolanic activity Lime Ciment -- Additius Chemistry Enginyeria civil::Materials i estructures::Materials i estructures de formigó [Àrees temàtiques de la UPC] Thermal and chemical activation Hydrated phases Geology Stratlingite Pozzolan Enginyeria dels materials::Materials ceràmics [Àrees temàtiques de la UPC] 021001 nanoscience & nanotechnology Chemical engineering engineering Pozzolanic reaction 0210 nano-technology Hydrate |
| Zdroj: | Biblos-e Archivo. Repositorio Institucional de la UAM instname UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) Biblos-e Archivo: Repositorio Institucional de la UAM Universidad Autónoma de Madrid Recercat. Dipósit de la Recerca de Catalunya Digital.CSIC. Repositorio Institucional del CSIC |
| ISSN: | 0169-1317 |
| DOI: | 10.1016/j.clay.2018.02.007 |
| Popis: | One inconvenience presented by the thermal activation of kaolinite-based wastes is their low content of metakaolinite, a highly pozzolanic product listed in current standards for the manufacture of commercial cements. The addition of a chemical activator during the thermal activation process is a priority line of research to increase the reactivity of the recycled metakaolinite. In this paper, an additional chemical activator, ZnO, is studied and its effect on both pozzolanic properties and the evolution of mineralogical phases in the thermal activation of coal waste with a reaction time of up to 90 days in the pozzolan/lime system. To do so, activation temperatures of between 550 °C/650 °C were selected and additions of chemical activator (ZnO) in percentages of between 0.0% and 3.0% by weight of coal waste, because it is an activator with a positive effect on a 100% natural kaolinite. The results showed that the incorporation of ZnO inhibited the reactivity of the recycled metakaolinite and in consequence, the capacity of the metakaolinite to react with the surrounding lime; even more so when the content of added chemical activator was raised, albeit with some exceptions, in the samples activated at 550 °C and 650 °C with 0.5% of chemical activator. In none of the cases under analysis was the chemical activator able to improve the properties of the metakaolinite in comparison with the properties of the reference sample activated only with temperature. The hydrated phases that appeared in the pozzolanic reaction were tetracalcium aluminate hydrate, stratlingite, monosulfoaluminate hydrate and LDH (phyllosilicate/carbonate) The authors wish to express their gratitude and sincere appreciation to the Spanish Ministry of the Economy and Competitiveness under coordinated projects MAT2012-37005-CO3-01, BIA2015-65558-C3-1-2-3R (MINECO/FEDER) for financing this research work and grateful to the Sociedad Anónima Hullera Vasco-Leonesa (Spain) and to the Spanish Cement Institute (IECA) for their assistance with this research. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect