Use of eggshell waste: A green and effective method for the synthesis of pure calcium hydroxide suspensions

This paper presents a rapid method to obtain pure suspensions of Ca(OH)2 dispersed in 2-propanol. To this aim eggshell wastes (CaCO3) were decarbonated to calcium oxide (CaO) followed by sonication-assisted hydrolysis in water/2-propanol to form calcium hydroxide (Ca(OH)2). An important advantage of...

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Detalles Bibliográficos
Autores: Lanzón Torres, Juan Marcos, Madrid Mendoza, Juan Antonio, Navarro Moreno, David, García Vera, Victoria Eugenia
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Universidad Politécnica de Cartagena(UPCT)
Repositorio:Repositorio Digital UPCT
OAI Identifier:oai:repositorio.upct.es:10317/13108
Acceso en línea:http://hdl.handle.net/10317/13108
https://www.sciencedirect.com/science/article/pii/S0950061823008188
Access Level:acceso abierto
Palabra clave:Eggshell
Calcium hydroxide
Nanoparticles
Consolidation
Architectural materials
Waste
Construcciones Arquitectónicas
2303.02 Elementos Alcalinotérreos
33 Ciencias Tecnológicas
Descripción
Sumario:This paper presents a rapid method to obtain pure suspensions of Ca(OH)2 dispersed in 2-propanol. To this aim eggshell wastes (CaCO3) were decarbonated to calcium oxide (CaO) followed by sonication-assisted hydrolysis in water/2-propanol to form calcium hydroxide (Ca(OH)2). An important advantage of the method is that it does not require chemical reagents due to the high purity of eggshell in CaCO3. Moreover, CaO is fully converted into Ca(OH)2 which means that purification steps are not needed, as occurs in conventional routes of synthesis. To assess the reliability of the synthetic procedure, the purity and amount of Ca(OH)2 were studied by X-ray diffraction (XRD), infrared spectroscopy (FTIR) and thermal analysis (TG). In addition, the morphology and crystallite size were examined by transmission electron microscopy (TEM) and X-ray diffraction (XRD) using Rietveld refinement method. It was found that sonicated Ca(OH)2 suspensions (5 g/L) were composed of particles that ranged in size from several nanometers to few micrometers. Finally, the suitability of Ca(OH)2 from eggshell to reinforce architectural stone was also studied by microscopy examination, colour change tests, surface hardness and surface erosion measurements. All tests confirmed the consolidation effectiveness was comparable to conventional nanolime treatments and surface erosion was visibly reduced.