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A platform for research: civil engineering, architecture and urbanism
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
Highlights The artificial aggregates manufactured can be classified as lightweight aggregates. High pre-firing times are preferred to manufacture lighter artificial aggregates. Low firing times and temperatures are preferred to produce lighter aggregates.
Abstract Washing aggregate sludge (WAS) from a gravel pit and sewage sludge (SS) from a wastewater treatment plant (WWTP) were analysed in terms of their physical, mineral and chemical characteristics. Both waste materials were mixed, milled and made into granules, pre-heated for 2 and 5min and sintered in a rotary kiln at temperatures between 1175°C and 1275°C for different dwell times ranging from 1 to 30min. The effects the raw material characteristics, pre-heating and heating temperatures and dwell times had on loss on ignition (LOI), mineralogy, bloating index (BI), loose bulk density (ρb), apparent and dry particle density (ρa,ρd), water absorption after 24h (WA24h) as well as the compressive strength (S) of the aggregates were all studied. The products obtained were classified as lightweight aggregates (LWAs) in accordance with the Standard EN-13055-1 (loose bulk density⩽1.20gcm−3 or particle density⩽2.00gcm−3). Their water absorption values were between 23.54% and 38.36% and compressive strength values between 1.23MPa and 3.03MPa. These properties were affected by the heating temperature, pre-firing and firing dwell times. The compressive strength values obtained were compared to those typically found for commercially available expanded clay aggregates (EXCAs) manufactured in Spain. According to these, it was possible to establish two groups of LWAs. The LWAs obtained in this research could potentially be used for the following commercial applications or for similar uses: horticulture, insulation, gardening, lightweight insulating concretes and/or prefabricated lightweight structures.
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
Highlights The artificial aggregates manufactured can be classified as lightweight aggregates. High pre-firing times are preferred to manufacture lighter artificial aggregates. Low firing times and temperatures are preferred to produce lighter aggregates.
Abstract Washing aggregate sludge (WAS) from a gravel pit and sewage sludge (SS) from a wastewater treatment plant (WWTP) were analysed in terms of their physical, mineral and chemical characteristics. Both waste materials were mixed, milled and made into granules, pre-heated for 2 and 5min and sintered in a rotary kiln at temperatures between 1175°C and 1275°C for different dwell times ranging from 1 to 30min. The effects the raw material characteristics, pre-heating and heating temperatures and dwell times had on loss on ignition (LOI), mineralogy, bloating index (BI), loose bulk density (ρb), apparent and dry particle density (ρa,ρd), water absorption after 24h (WA24h) as well as the compressive strength (S) of the aggregates were all studied. The products obtained were classified as lightweight aggregates (LWAs) in accordance with the Standard EN-13055-1 (loose bulk density⩽1.20gcm−3 or particle density⩽2.00gcm−3). Their water absorption values were between 23.54% and 38.36% and compressive strength values between 1.23MPa and 3.03MPa. These properties were affected by the heating temperature, pre-firing and firing dwell times. The compressive strength values obtained were compared to those typically found for commercially available expanded clay aggregates (EXCAs) manufactured in Spain. According to these, it was possible to establish two groups of LWAs. The LWAs obtained in this research could potentially be used for the following commercial applications or for similar uses: horticulture, insulation, gardening, lightweight insulating concretes and/or prefabricated lightweight structures.
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
González-Corrochano, Beatriz (author) / Alonso-Azcárate, Jacinto (author) / Rodríguez, Luis (author) / Lorenzo, Agripino Pérez (author) / Torío, María Fernández (author) / Ramos, Juan José Tejado (author) / Corvinos, María Dolores (author) / Muro, Carlos (author)
Construction and Building Materials ; 116 ; 252-262
2016-04-25
11 pages
Article (Journal)
Electronic Resource
English
<italic>BI</italic> , bloating index , <italic>BM</italic> , bulk mineralogy , <italic>CM</italic> , clay mineralogy , <italic>EXCAs</italic> , expanded clay aggregates , <italic>IC</italic> , inorganic carbon content , <italic>I.C.</italic> , identification code , <italic>ICP-AES</italic> , inductively coupled plasma-atomic emission spectroscopy , <italic>LOI</italic> , loss on ignition , <italic>LOI<inf>rm</inf></italic> , loss on ignition of raw materials , <italic>LOI<inf>total</inf></italic> , total loss on ignition of granules , <italic>LOI<inf>1</inf></italic> , loss on ignition of granules in <italic>zone 1</italic> , <italic>LOI<inf>1+2</inf></italic> , combined loss on ignition of granules in <italic>zone 1</italic> and <italic>zone 2</italic> , <italic>LWA</italic> , lightweight aggregate , <italic>OA</italic> , oriented aggregates , <italic>OC</italic> , organic carbon content , <italic>R</italic> , correlation value , <italic>S</italic> , compressive strength , <italic>Si/∑F</italic> , SiO<inf>2</inf>/<italic>∑</italic>Fluxing (CaO<hsp></hsp>+<hsp></hsp>MgO<hsp></hsp>+<hsp></hsp>K<inf>2</inf>O<hsp></hsp>+<hsp></hsp>Na<inf>2</inf>O<hsp></hsp>+<hsp></hsp>FeO<hsp></hsp>+<hsp></hsp>Fe<inf>2</inf>O<inf>3</inf>) ratio , <italic>SS</italic> , Sewage sludge , <italic>TC</italic> , total carbon content , <italic>Tsl</italic> , temperature selected by the user in <italic>zone 2</italic> , <italic>WAS</italic> , washing aggregate sludge , <italic>WWTP</italic> , wastewater treatment plant , <italic>WA<inf>24h</inf></italic> , water absorption after 24<hsp></hsp>h , <italic>W25S75</italic> , a mixture of washing aggregate sludge and sewage sludge 25:75 w/w , <italic>W50S50</italic> , a mixture of washing aggregate sludge and sewage sludge 50:50 w/w , <italic>W75S25</italic> , a mixture of washing aggregate sludge and sewage sludge 75:25 w/w , <italic>XRD</italic> , X-ray diffraction , <italic>z1</italic> , <italic>zone 1</italic> (pre-firing area) , <italic>z2</italic> , <italic>zone 2</italic> (firing area) , <italic>z3</italic> , <italic>zone 3</italic> (cooling area) , <italic>ρ<inf>a</inf></italic> , apparent particle density , <italic>ρ<inf>b</inf></italic> , loose bulk density , <italic>ρ<inf>d</inf></italic> , dry particle density , <italic>∑F</italic> , <italic>∑</italic>Fluxing (CaO<hsp></hsp>+<hsp></hsp>MgO<hsp></hsp>+<hsp></hsp>K<inf>2</inf>O<hsp></hsp>+<hsp></hsp>Na<inf>2</inf>O<hsp></hsp>+<hsp></hsp>FeO<hsp></hsp>+<hsp></hsp>Fe<inf>2</inf>O<inf>3</inf>) , Bloating , Lightweight aggregate , Washing aggregate sludge , Waste valorization
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
| Online Contents | 2016
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
| British Library Online Contents | 2016
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
| British Library Online Contents | 2016
Valorization of washing aggregate sludge and sewage sludge for lightweight aggregates production
| British Library Online Contents | 2016