CEMENT & CONCRETE COMPOSITES
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2020
·
IF 6.257
Woo Sung Yum,Jung-Il Suh,Dongho Jeon,Jae Eun Oh
This study investigated the effect of calcium formate (CF) on the strength development and microstructure of the CaO-activated ground granulated blast furnace slag (GGBFS) system. The main activator (i.e., CaO) was fixed at 4 wt%, and the GGBFS was replaced with CF at 0, 1, 3, and 5 wt%. The use of CF significantly increased the strength of the binder system by inducing (1) more dissolution of GGBFS, (2) greater C–S–H formation although when CF was used over a certain limit (i.e., 3 wt%), the formation of C–S–H began to be disturbed, and most importantly, (3) an increase in C2AH8 formation. In this study, although the greater formation of C2AH8 was the main cause of the strength enhancement, the C2AH8 phase also likely increased porosity and reduced strength as it was metastable; thus, strength increasing effect and reducing effect likely offset each other; thus, with increasing CF dosage, when the former was more dominant, the strength was enhanced (e.g., up to 3 wt%), but when the latter was larger, the strength enhancement decreased (e.g., at 5 wt%).
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
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2020
·
IF 4.419
Woo Sung Yum,Jung-Il Suh,Do Hoon Kim,Jae Eun Oh
Recently, the combined use of calcium oxide (CaO) and calcium formate (Ca(HCOO) 2 ) has been proposed as an alternative activator for ground granulated blast furnace slag (GGBFS) (referred to as CaO-Ca(HCOO) 2 -activated GGBFS system). However, this clinker-free binder system produces calcium aluminate hydrate (C 2 AH 8 ), generally leading to the degradation of cementitious binder systems by its conversion to other phases. Thus, in this study, attempts to remove C 2 AH 8 from this system without losing the strength are suggested by the use of two additives (i.e., calcium sulfate (CaSO 4 ) and calcium nitrate (Ca(NO 3 ) 2 ), respectively). Results revealed that the above-mentioned additives completely remove C 2 AH 8 in the initial curing stage via its conversion to ettringite or NO 3 - and NO 2 -AFm, respectively. In addition, the additives reduced the extent of the total shrinkage and the standard deviation of strength results of triplicate samples. However, CaSO 4 exerted a beneficial effect on the strength, while Ca(NO 3 ) 2 exerted a marginal or detrimental effect on the strength. Therefore, this study suggested a new mixture form of an activator, comprising CaO , Ca(HCOO) 2 , and CaSO 4 , to activate GGBFS for maintaining strength without the conversion issue of C 2 AH 8 .
研究领域:
建筑材料学
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材料科学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
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2021
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IF 9.297
Zhenhai Xu,Jianming Gao,Yasong Zhao,Shujun Li,Zhaoheng Guo,Xu Luo,Gaofeng Chen
Utilization of high volume ground granulated blast furnace slag (GGBS) to produce cement-based materials (CBMs) meets the requirements of sustainable development. However, high volume GGBS will significantly reduce some properties of CBMs. Incorporation of nanosilica is a potentially feasible approach to solve the problem. In present paper, effects of nanosilica (1 wt%, 2 wt% and 3 wt%) on hydration and microstructure of blended cement incorporating high volume GGBS (80 wt%) have been studied by testing setting time, compressive strength , hydration heat, hydration products and pore structure . Results reveal that nanosilica shortens the initial and final setting time of blended cement by 10.75%–20.56% and 10.45%–23.00%, respectively. Furthermore, nanosilica enhances early hydration heat release rate of cement and GGBS. Meanwhile, nanosilica increases cumulative heat release of blended cement by 23.40%–26.46%. However, nanosilica hinders cement hydration after curing for 7 d. Results of thermal analysis indicate that 80 wt% GGBS significantly reduces the content of chemically bound water, while nanosilica improves the parameter by 1.32%–5.91% at 56 d. Additionally, 80 wt% GGBS increases cumulative porosity by 31.89% at 28 d, but nanosilica decreases cumulative porosity by 3.05% at 28 d. Both high volume GGBS and nanosilica can decrease average pore diameter and enhance microstructure of cement paste . Ultimately, nanosilica increases the 28 d compressive strength by 8.27%–19.23%, which partially compensates for the reduction of compressive strength caused by high volume GGBS. This paper can provide the essential foundation for the theory of nanosilica-modified CBMs with high volume GGBS, help to improve the effective utilization rate of GGBS and realize sustainable development of CBMs.
研究领域:
建筑材料学
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可持续发展工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2024
·
IF 2.2
Fengrong Zhang,Cuilan Zhang,Binghan Zhang,Dandan Han,Longwei Du,Lishun Wu
Blast furnace slag (BFS) is a kind of waste produced in industrial production, as well as a valuable secondary resource. In this paper, layered double hydroxides composites (BFS/LDHs) were prepared by aqueous polymerization, with industrial waste BFS as modifier and magnesium nitrate, aluminium nitrate, and urea as raw materials. BFS/LDHs have been characterized by using scanning electron microscopy (SEM), fourier infrared spectrometer (FT IR), x-ray diffraction (XRD), and the specific surface area analyser (BET). The adsorption of BFS/LDHs on Cu (II) and methylene blue (MB) was investigated by batch experiments. The results showed that the adsorption capacity of BFS/LDHs to Cu (II) is stronger than that of MB. What’s more, the solid concentration effect was found in the process of sorption kinetics and sorption isotherms. The sorption kinetics curves of Cu (II) and MB on BFS/LDHs were well fitted by the quasi-second-order kinetics under different adsorbent concentrations. Langmuir and Freundlich sorption isotherm models were used to analyse the adsorption. It showed that the adsorption conforms to Langmuir and Freundlich’s adsorption isotherm models. The BFS/LDHs composites have good recycling availability in this adsorption process of Cu (II) and MB, the removal capacity of which was reduced by 16.1% and 3.8% after being recycled for six times, respectively. More importantly, BFS/LDHs composites are not only expected to become a sewage treatment agent, but also to solve the problem of industrial waste treatment, which is a win–win strategy.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sustainability
·
2021
·Vol. 13
·期 20
·11144
·
IF 3.251
Wei Zhao,Xiaofeng Huang,Bingji Yan,Shaoyan Hu,Hongwei Guo,Dong Chen
Diopside-based glass-ceramics are successfully produced by recycling blast furnace slag and fluorite tailing with the addition of supplementary elements such as TiO2, Fe2O3and Cr2O3as nucleation agents, using a conventional melting method. The effects of various nucleating agents on the phase components and structure of the prepared glass-ceramics were evaluated by a differential scanning calorimeter, X-ray diffraction and scanning electron microscope–energy disperse spectrometer methods to determine the optimal dosage of nucleating agents. The results show that, in the preparation of diopside-based glass-ceramics, the suitable percentages of blast furnace and fluorite tailing are 55% and 45%, and the recommended composite nucleating agents consist of 1.5% Cr2O3, 2% TiO2and 3% Fe2O3. Heat treatment was conducted at a nucleation temperature of 720 °C and a crystallization temperature of 920 °C, and the nucleation and crystallization durations were 1.0 h and 1.5 h, respectively. Under the abovementioned parameters, the obtained diopside-based glass-ceramics displayed a Vickers hardness of 7.12 GPa, density of 2.95 g·cm−3, water absorption of 0.02%, acid resistance of 0.23% and alkali resistance of 0.02%.Keywords:blast furnace slag;fluorite tailing;diopside;glass-ceramics;nucleating agent
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 17
·4409
·
IF 3.1
Yuxiang Chen,Shengping Wu,Hanhui Huang,Feng Rao,Lang Yang
This study aims to compare the effects of three calcium compounds on the workability, setting time and mechanical properties of red mud (RM)–blast furnace slag (BFS)-based geopolymers. The crystalline phase, hydration process and microstructure of RM-BFS-based geopolymers were characterized by X-ray diffraction (XRD), heat evolution, X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) tests. The results showed that an appropriate amount of calcium compounds can improve the flowability and compressive strength of the geopolymers, but the excessiveness causes a decrease in strength due to rapid hardening. Other than calcium carbonate, both calcium oxide and calcium chloride played important roles in accelerating the setting times of RM-BFS-based geopolymers. The acceleration in the setting times of geopolymers could be attributed to the calcium hydroxide produced by the dissolution of the calcium compounds, which also provides nucleation sites for the geopolymerization reaction. This study gives new insights into the effect of calcium on the setting times and mechanical properties of geopolymers in the geopolymerization process.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water
·
2021
·Vol. 13
·期 19
·2735
·
IF 3.103
Yali Wang,Huining Li,Suping Cui,Qi Wei
The potential possibility of blast furnace slag as a low-cost adsorbent to remove lead ions from wastewater was investigated in detail in the present work. Both single factor experiment and orthogonal experiment were performed to reveal the effect of pH, adsorption temperature, contact time and initial concentration of lead ions on the adsorption performance of pristine slag. In order to make clear the correlation between the lead ion adsorption performance and the structure of slag, solid state nuclear magnetic resonance (NMR) was conducted to reveal the network structure and X-ray fluorescence (XRF) was used to calculate the nonbridging oxygen in the network-forming tetrahedra. For the purpose of improving the adsorption performance, γ-aminopropyltriethoxysilane (APTES) was adopted to modify the slag via post-grafting method. The results show that the slag is predominately composed of SiO2, Al2O3, CaO and MgO, exhibiting an amorphous network structure based on SiO4and AlO4tetrahedra. The conditions for adsorption can be optimized as follows: a pH of 7, an adsorption temperature of 60 °C, a contact time of 120 min and an initial lead ion concentration of 40 mg·L−1. Under the optimal conditions, a removal rate of 99.98% and an adsorption capacity of 49.99 mg·g−1are obtained for the pristine slag. The adsorption complies with the Langmuir model thermodynamically and conforms to the pseudo-second order model kinetically. It is noted that aminopropyl-modification has considerably enhanced the removal rate of lead ions from 20.71 to 64.32% and the adsorption capacity from 29.01 to 96.48 mg·g−1since amino groups (-NH2) are more inclined to form a complex with lead ions than hydroxyl groups due to the higher nucleophilicity of amino groups than that of hydroxyl groups. However, it is necessary to develop more low-cost modification agents in the future work.Keywords:blast furnace slag;lead ions;adsorption;surface modification;aminopropyl groups
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2020
·
IF 4.419
Chunbao Li,Baoguo Ma,Hongbo Tan,Ting Zhang,Xiaohai Liu,Pian Chen
Chloride was one of important factors resulting in steel bar corrosion in reinforced concrete when using sea resources. In this paper, an attempt to promote the chloride binding capacity of the cement-ground-granulated blast furnace slag (GGBS) system was made by adding triisopropanolamine (TIPA). The paste was prepared by 70 wt% cement and 30 wt% GGBS, sodium chloride, TIPA (0.03%, 0.06% and 0.10%, by weight of binder) and water. The paste was cured for 7 d and 60 d, and the chloride binding ratio (CBR) were measured. The hydration heat and compressive strength were examined, then the hydrates and pore structure of the hardened paste were also analyzed; and the effect of TIPA on aluminum and ferric dissolution of GGBS was also studied. The results showed that TIPA could promote CBR at both 7 d and 60 d. The reason was ascribed to three aspects: (1) TIPA facilitate the formation of FS, which contribute to chemical binding; (2) TIPA promoted the formation of C-S(A)-H gel, which would increase the physical binding; (3) TIPA refined the pore structure and increased fractal dimension, which could enhance the migration resistance. Furthermore, TIPA promoted cement hydration and pozzolanic reaction of GGBS by facilitated the dissolution of aluminum and ferric in GGBS. Additionally, the formation of Friedel's salt was promoted due to the transformation of ettringite to AFm-like phase promoted by TIPA. Such results suggested a new way to improve chloride binding capacity of cementitious materials by adding alkanolamine.
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
·
IF 7.4
Linqiao Qin,Lin Shao,Min Yi,Yu She,Yu Liu,Wenwen Chen,Yuxiao Jiang,Kaituo Wang
Tetracycline hydrochloride (TC) is currently treated mostly with photocatalysts that the preparation process is complicated and costly, limiting its large-scale application. In this study, slag-based geopolymer microspheres (SGMs) photocatalysts were prepared from low-cost slag as raw material using geopolymer technology, and excellent visible-light degradation properties for TC could be obtained by simple calcination. When the water addition was 4 g, the stirring speed was 1000 rpm and the calcination temperature was 800 °C for 3 h, the initial pH was 4.72 and the photocatalyst dosage was 0.4 g/L, SGMs showed excellent photocatalytic performance for TC with 94.76 % degradation in visible-light. Compared with the traditional powder materials, SGMs can achieve rapid separation with excellent settling performance (it can be completely settled within 1 min). With degradation rate remaining over 90 % after five cycles, it showed excellent cyclic stability. The degradation mechanism of SGMs on TC was as follows: firstly, TC adsorption takes place on the SGMs surface during the dark reaction stage; secondly, with Ca 2+ in the SGMs enter the solution, it complexed with the TC, making it positively charged and accelerating the generation of free radicals, adsorption and degradation occurred simultaneously, with the order of active free radical action on TC degradation being ·O 2 - >·OH > h + . The SGMs prepared in this project has the benefits of being inexpensive, easy to operate, environmental protection, excellent visible-light photocatalyst performance, and potential industrial application prospects.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2025
·Vol. 32
·期 12
·3072-3085
·
IF 7.2
Zhang Qian,Liu Bo,An Changcong,Li Qiong,Liu Jiling,Wei Siyu,Fan Jiaxing,Sun Zhe,Zhang Dichuan,Pulatov Bakhtiyor
The effect of heavy metals on the properties and hydration of blast furnace slag–cement composites (BFS-CC) remain unclear. In this study, two BFS-CC (denoted as DBFS-CC and WBFS-CC) were prepared by dry and wet grinding of BFS, respectively. The effect of Cu(II) on BFS-CC’s properties and hydration was investigated by adding representative copper contaminants (CuO, CuCl 2 , and CuS) to the composites. Adding 1.0wt% CuO and 0.5wt% CuS increased the 3-d compressive strength of DBFS-CC by 14.9% and 5.7%, respectively, but suppressed the 3-d strength of WBFS-CC. This trend reversed at 28-d curing, where adding 1.5wt% CuO, 2.0wt% CuCl 2 , and 1.5wt% CuS enhanced the compressive strength of WBFS-CC by 23.4%, 6.2%, and 13.6%, respectively, but adversely affected the strength of DBFS-CC. For 28-d hydration, adding CuCl 2 decreased the hydration degree of DBFS-CC but enhanced that of WBFS-CC. Adding CuO promoted the hydration degree of both composites, while adding CuS exhibited inhibitory effects. DBFS-CC immobilized CuCl 2 better due to a higher hydration degree, while WBFS-CC immobilized CuO and CuS better due to having finer unhydrated BFS particles and a denser matrix. This study not only focuses on the Cu(II) immobilization effect but also reveals the differential effects of Cu(II) species on the hydration process, providing novel insights into heavy metal interactions in BFS-CC systems and their safe disposal.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Tiange Yang,Zhenxin Duan,Ying Song,Jingshi Zhang,Xiaolei Song,Hongli Wang
Water-quenched blast furnace slag (BFS), a by-product of the steel industry, is highly important for environmental protection and resource conservation through its recycling. This study used BFS as the primary raw material and sodium dodecyl sulfate as the foaming agent to fabricate ceramic foams using the particle-stabilized foam method. The effects of slurry pH and sintering temperature on the microstructure and properties of the ceramic foams were studied. The results showed that as the slurry pH increased, the pore size of the ceramic foams first increased and then decreased, and the compressive strength first decreased and then increased accordingly. With increasing sintering temperature, both the pore size and porosity of the ceramic foams gradually decreased, resulting in increased compressive strength and thermal conductivity. At a pH of 5 and a sintering temperature of 1100 °C, the ceramic foams exhibited optimal performance with a porosity of 75.6 %, compressive strength of 1.11 MPa, and thermal conductivity of 0.0548 W/(m·K). These properties suggest potential applications as thermal insulation materials in buildings. The findings provide valuable insights into the preparation and performance optimization of BFS-derived ceramic foams.
研究领域:
材料科学
·
陶瓷工程
·
环境科学
·
建筑材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Wenhao Liu,Qingcai Chen,Tengfei Xu,Sitong Liu,Yifan Sun,Huadong Huang
Low-cost support materials and simple synthesis methods can significantly reduce the cost of solid amine technology, which is crucial for its commercialization. This research work utilized blast furnace slag as raw material and adopted a green, simple treatment method to prepare the support materials (BFSC), which exhibited high specific surface area (238.83 m 2 /g) and pore volume (1.09 cm 3 /g). The main component of the support material is magnesium aluminum metasilicate. The support material was modified with different contents of polyethyleneimine (PEI) and tetraethylenepentamine (TEPA), the results showed that BFSC-50 %TEPA exhibited the best CO 2 adsorption performance (3.27 mmol/g). Subsequently, the effects of adsorption conditions on BFSC-50 %TEPA were investigated, including temperature, humidity, and different gas compositions. In atmosphere condition of 15 % CO 2 and 85 % air (with 60 % humidity), high temperatures promote the formation of a urea derivative, which significantly impairs the material’s CO 2 adsorption capacity. Finally, the cyclic stability of BFSC-50 %TEPA was tested.
研究领域:
环境科学
·
化学工程
·
材料科学
·
碳捕集与封存
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）