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Mechanical properties and hydration mechanism of high-volume ultra-fine iron ore tailings cementitious materials
Highlights A blended low-carbon cementitious materials containing high-volume mine solid waste activated ultra-fine IOT is designed. IOT2 has higher pozzolanic activity and better dense filling effect. IOT2 can consume more portlandite produced from cement hydration to form more rigid hydration products. The increase of later compressive strength owes to the synergistic action of the improvement of hydrates and filler effect.
Abstract Iron ore tailings (IOT) are a type of mining solid waste and cause many environmental and safety problems. The aim of this paper was to investigate the effect of high-volume ultra-fine IOT on the mechanical properties and hydration mechanism of cementitious materials. To obtain ultra-fine particles, IOT was processed via grinding in water, and the particle characteristics were characterized using a laser particle-size analyzer, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and inductively coupled plasma (ICP). The influence of the IOT particle size (D50 = 47.63 μm, 4.32 μm, 1.09 μm), substitution percentage (30 %, 40 %, 50 %), and hydration age (1 d, 7 d, 28 d) on the compressive strength of mortar specimens were also studied. The results show that ultra-fine treatment enhances the hydration activity of IOT particles and has a positive effect on the mechanical properties of cementitious materials. The addition of IOT increases the setting time and reduces the hydration heat at early hydration stage; however, the ultra-fine treatment can minimize this problem and meet the requirements of practical engineering applications. Compared with raw IOT, the ultra-fine IOT exhibits more remarkable filling effect and hydration activity. They can consume a large amount of portlandite, which is produced by cement hydration to form densified calcium silicate hydrate gel and accelerate the development of strength. This study provides a design method and experimental data support for the preparation of a kind of low-carbon cementitious materials.
Mechanical properties and hydration mechanism of high-volume ultra-fine iron ore tailings cementitious materials
Highlights A blended low-carbon cementitious materials containing high-volume mine solid waste activated ultra-fine IOT is designed. IOT2 has higher pozzolanic activity and better dense filling effect. IOT2 can consume more portlandite produced from cement hydration to form more rigid hydration products. The increase of later compressive strength owes to the synergistic action of the improvement of hydrates and filler effect.
Abstract Iron ore tailings (IOT) are a type of mining solid waste and cause many environmental and safety problems. The aim of this paper was to investigate the effect of high-volume ultra-fine IOT on the mechanical properties and hydration mechanism of cementitious materials. To obtain ultra-fine particles, IOT was processed via grinding in water, and the particle characteristics were characterized using a laser particle-size analyzer, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and inductively coupled plasma (ICP). The influence of the IOT particle size (D50 = 47.63 μm, 4.32 μm, 1.09 μm), substitution percentage (30 %, 40 %, 50 %), and hydration age (1 d, 7 d, 28 d) on the compressive strength of mortar specimens were also studied. The results show that ultra-fine treatment enhances the hydration activity of IOT particles and has a positive effect on the mechanical properties of cementitious materials. The addition of IOT increases the setting time and reduces the hydration heat at early hydration stage; however, the ultra-fine treatment can minimize this problem and meet the requirements of practical engineering applications. Compared with raw IOT, the ultra-fine IOT exhibits more remarkable filling effect and hydration activity. They can consume a large amount of portlandite, which is produced by cement hydration to form densified calcium silicate hydrate gel and accelerate the development of strength. This study provides a design method and experimental data support for the preparation of a kind of low-carbon cementitious materials.
Mechanical properties and hydration mechanism of high-volume ultra-fine iron ore tailings cementitious materials
Li, Hua-Wei (author) / Wang, Rong (author) / Wei, Mu-Wang (author) / Lei, Neng-Zhong (author) / Sun, Hao-Xu (author) / Fan, Jia-Jun (author)
2022-09-06
Article (Journal)
Electronic Resource
English
Hydration Reaction of Cementitious Materials Prepared with Molybdenum Tailings
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