A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Immobilization mechanism of radioactive borate waste in phosphate-based geopolymer waste forms
Abstract The solidification of radioactive borate waste (BW), which contains a high concentration of boron ions using cement waste forms is challenging because soluble borate hinders the cement hydration reaction. Here, BW was immobilized using a phosphate-based geopolymer, and the phase change of BW in the geopolymer was investigated. The geopolymers could solidify BW up to 50 wt% depending on the water content and heat curing conditions. In geopolymers cured at high temperatures (60 and 90 °C), the 7-day compressive strength increased as the BW waste loading increased up to 40 wt%. Heat curing promoted geopolymerization and the precipitation of amorphous boron phosphate, leading to an increase in the compressive strength. The formation of a new amorphous boron phosphate phase was confirmed by performing XRD, MAS NMR, and SEM analyses of the geopolymers and reaction products. These results can improve our understanding of the immobilization mechanism of BW in phosphate-based geopolymers.
Graphical abstract Display Omitted
Highlights Phosphate-based geopolymers can immobilize borate waste up to 50 wt%. Amorphous boron phosphate is formed along with the geopolymer binder. 7-day compressive strength of geopolymer is proportional to borate waste loading. Amorphous boron phosphate contributes to the enhancement in compressive strength.
Immobilization mechanism of radioactive borate waste in phosphate-based geopolymer waste forms
Abstract The solidification of radioactive borate waste (BW), which contains a high concentration of boron ions using cement waste forms is challenging because soluble borate hinders the cement hydration reaction. Here, BW was immobilized using a phosphate-based geopolymer, and the phase change of BW in the geopolymer was investigated. The geopolymers could solidify BW up to 50 wt% depending on the water content and heat curing conditions. In geopolymers cured at high temperatures (60 and 90 °C), the 7-day compressive strength increased as the BW waste loading increased up to 40 wt%. Heat curing promoted geopolymerization and the precipitation of amorphous boron phosphate, leading to an increase in the compressive strength. The formation of a new amorphous boron phosphate phase was confirmed by performing XRD, MAS NMR, and SEM analyses of the geopolymers and reaction products. These results can improve our understanding of the immobilization mechanism of BW in phosphate-based geopolymers.
Graphical abstract Display Omitted
Highlights Phosphate-based geopolymers can immobilize borate waste up to 50 wt%. Amorphous boron phosphate is formed along with the geopolymer binder. 7-day compressive strength of geopolymer is proportional to borate waste loading. Amorphous boron phosphate contributes to the enhancement in compressive strength.
Immobilization mechanism of radioactive borate waste in phosphate-based geopolymer waste forms
Kim, Byoungkwan (author) / Kang, Jaehyuk (author) / Shin, Younglim (author) / Yeo, Tae-min (author) / Um, Wooyong (author)
2022-08-26
Article (Journal)
Electronic Resource
English
GEOPOLYMER COMPOSITION FOR SOLIDIFYING RADIOACTIVE WASTE
| European Patent Office | 2022
Combustion synthesis of radioactive waste immobilization
| British Library Online Contents | 2005
Geopolymer curing method for fluorine-containing radioactive waste liquid
| European Patent Office | 2024
A manufacturing method of geopolymer using radioactive concrete waste
| European Patent Office | 2024