A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Heating aluminum dross: Harmless process and utilization as cement admixture
https://orcid.org/0000-0002-6279-4454
Abstract Phosphogypsum (PG) and aluminum dross (AD) with harmful impurities seriously hinder its large-scale engineering utilization. In this paper, the properties of AD and PG as cement admixture were investigated with the aim of reducing the environmental pollution and landfill stockpiling pressure. The migration and transformation rules under crucial factors were analyzed by different characterization methods while AD was heated at different temperature. Then, the compressive strength, soluble phosphorus and fluorine concentration, hydration heat and expansion rate of specimens prepared with AD, PG, and Portland cement (PC) were evaluated to illustrate the hydration mechanism. Compared to the other experiment sets, the results indicated that AD treated at 900°C not only had a higher nitrogen removal rate, but also maintained hydration activity at a relatively high level. Moreover, Heating AD at 900℃ effectively accelerated the dissolution of gypsum and calcium silicate, resulting in increased formation of ettringite (AFt), calcium silicate hydrates (C-S-H) and calcium aluminium hydrates (C-A-H). When the binder consisted of 14% heated aluminium dross (HAD), 6% PG, and 80% PC, the specimen reached the highest compressive strength value at 25.87 MPa. This work provided a new strategy for synergistic utilization of PG and AD, promoting the development of environment-friendly industrial wastes-based cementitious materials effectively.
Highlights Harmless treatment of aluminum dross containing nitrogen, fluorine, chlorine was accomplished by heating. Heated aluminum dross was utilized as cement mixture with Phosphogypsum and Portland cement. HAD treated at 900°C is able to avoid destructive expansion but maintain hydration activity at relatively high level. Paste PS900(30%HAD-10%PG-60%PC) had a 35.18% much higher compressive strength than that of PSW(10%PG-90%PC). Soluble phosphorus and fluorine were immobilized in the process of synergistic hydration.
Heating aluminum dross: Harmless process and utilization as cement admixture
https://orcid.org/0000-0002-6279-4454
Abstract Phosphogypsum (PG) and aluminum dross (AD) with harmful impurities seriously hinder its large-scale engineering utilization. In this paper, the properties of AD and PG as cement admixture were investigated with the aim of reducing the environmental pollution and landfill stockpiling pressure. The migration and transformation rules under crucial factors were analyzed by different characterization methods while AD was heated at different temperature. Then, the compressive strength, soluble phosphorus and fluorine concentration, hydration heat and expansion rate of specimens prepared with AD, PG, and Portland cement (PC) were evaluated to illustrate the hydration mechanism. Compared to the other experiment sets, the results indicated that AD treated at 900°C not only had a higher nitrogen removal rate, but also maintained hydration activity at a relatively high level. Moreover, Heating AD at 900℃ effectively accelerated the dissolution of gypsum and calcium silicate, resulting in increased formation of ettringite (AFt), calcium silicate hydrates (C-S-H) and calcium aluminium hydrates (C-A-H). When the binder consisted of 14% heated aluminium dross (HAD), 6% PG, and 80% PC, the specimen reached the highest compressive strength value at 25.87 MPa. This work provided a new strategy for synergistic utilization of PG and AD, promoting the development of environment-friendly industrial wastes-based cementitious materials effectively.
Highlights Harmless treatment of aluminum dross containing nitrogen, fluorine, chlorine was accomplished by heating. Heated aluminum dross was utilized as cement mixture with Phosphogypsum and Portland cement. HAD treated at 900°C is able to avoid destructive expansion but maintain hydration activity at relatively high level. Paste PS900(30%HAD-10%PG-60%PC) had a 35.18% much higher compressive strength than that of PSW(10%PG-90%PC). Soluble phosphorus and fluorine were immobilized in the process of synergistic hydration.
Heating aluminum dross: Harmless process and utilization as cement admixture
https://orcid.org/0000-0002-6279-4454
Abstract Phosphogypsum (PG) and aluminum dross (AD) with harmful impurities seriously hinder its large-scale engineering utilization. In this paper, the properties of AD and PG as cement admixture were investigated with the aim of reducing the environmental pollution and landfill stockpiling pressure. The migration and transformation rules under crucial factors were analyzed by different characterization methods while AD was heated at different temperature. Then, the compressive strength, soluble phosphorus and fluorine concentration, hydration heat and expansion rate of specimens prepared with AD, PG, and Portland cement (PC) were evaluated to illustrate the hydration mechanism. Compared to the other experiment sets, the results indicated that AD treated at 900°C not only had a higher nitrogen removal rate, but also maintained hydration activity at a relatively high level. Moreover, Heating AD at 900℃ effectively accelerated the dissolution of gypsum and calcium silicate, resulting in increased formation of ettringite (AFt), calcium silicate hydrates (C-S-H) and calcium aluminium hydrates (C-A-H). When the binder consisted of 14% heated aluminium dross (HAD), 6% PG, and 80% PC, the specimen reached the highest compressive strength value at 25.87 MPa. This work provided a new strategy for synergistic utilization of PG and AD, promoting the development of environment-friendly industrial wastes-based cementitious materials effectively.
Highlights Harmless treatment of aluminum dross containing nitrogen, fluorine, chlorine was accomplished by heating. Heated aluminum dross was utilized as cement mixture with Phosphogypsum and Portland cement. HAD treated at 900°C is able to avoid destructive expansion but maintain hydration activity at relatively high level. Paste PS900(30%HAD-10%PG-60%PC) had a 35.18% much higher compressive strength than that of PSW(10%PG-90%PC). Soluble phosphorus and fluorine were immobilized in the process of synergistic hydration.
Heating aluminum dross: Harmless process and utilization as cement admixture
Qing, Sancheng (author) / Ma, Liping (author) / Wang, Xin (author) / Ao, Ran (author) / Xue, Guanghai (author) / Wang, Yongguang (author) / Pan, Shewei (author) / Wu, Meng (author)
2024-03-03
Article (Journal)
Electronic Resource
English
Harmless treatment and recycling of secondary aluminum dross: a review
| Taylor & Francis Verlag | 2023
CEMENT ADMIXTURE, CEMENT ADMIXTURE MANUFACTURING METHOD, AND CEMENT COMPOSITION
| European Patent Office | 2023