|
authors |
Delgado-Plana, P; Rodriguez-Exposito, A; Bueno-Rodriguez, S; Perez-Villarejo, L; Tobaldi, DM; Labrincha, JA; Eliche-Quesada, D |
|
nationality |
International |
|
journal |
SUSTAINABILITY |
|
author keywords |
spent bleaching earth; geopolymers; activating solution; activator modulus; compressive strength; microstructure |
|
keywords |
ASH-BASED-GEOPOLYMERS; FLY-ASH; WASTE GLASS; INORGANIC GEOPOLYMERS; MECHANICAL-PROPERTIES; PART I; CEMENT; SODIUM; FABRICATION; RESISTANCE |
|
abstract |
The valorization of spent oil bleaching earths (SOBE) is crucial for the protection of the environment and the reuse of resources. In this research, alkali-activated binders were manufactured at room temperature using SOBE as a precursor by varying the mass ratio between the activating solutions of sodium silicate (Na2SiO3) and 6 M sodium hydroxide (NaOH) (activating solution modulus) (Na2SiO3/NaOH ratio = 1/1; 1/2; 1/3; 1/4) to investigate the influence on the technological properties of the materials. This process intends to evaluate the potential of SOBE, heat-treated at 550 degrees C (1 h), as a precursor of the reaction (source of aluminosilicates). Samples produced with higher amounts of sodium silicate developed a denser structure, with lower porosity and a higher amount of geopolymer gel. Maximum flexural (8.35 MPa) and compressive (28.4 MPa) strengths of samples cured at room temperature for 28 days were obtained with a Na2SiO3/NaOH mass ratio of 1/1. The study demonstrates that SOBE waste can be used as a precursor in the manufacture of geopolymer binders that show a good compromise between physical, mechanical and thermally insulating characteristics. |
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publisher |
MDPI |
|
isbn |
2071-1050 |
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year published |
2021 |
|
volume |
13 |
|
issue |
13 |
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digital object identifier (doi) |
10.3390/su13137501 |
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web of science category |
18 |
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subject category |
Green & Sustainable Science & Technology; Environmental Sciences; Environmental Studies |
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unique article identifier |
WOS:000671318600001
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