Journal of Sustainable Metallurgy
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2025
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IF 3.2
Shao Shuang,Ma Baozhong,Wang Chengyan,Chen Yongqiang
Extracting Al from coal gangue has the double benefits of realizing the high-value application of coal gangue and mitigating the scarcity of bauxite resource. The key Al-containing minerals in coal gangue include kaolinite and boehmite, and thermal activation is pivotal for stimulating their reactivity. In this study, kaolinite and boehmite were subjected to thermal activation and acid leaching to explore the intrinsic link between their thermal evolution and leaching activity. Results showed that the phase evolution of kaolinite followed a multi-step sequential process in the order of kaolinite → metakaolinite → γ -Al 2 O 3 → mullite, and Al V in metakaolinite was highly active. For boehmite, it underwent the transformation of boehmite → γ -Al 2 O 3 → δ -Al 2 O 3 → θ -Al 2 O 3 and α -Al 2 O 3 successively. Their reactivity in descending order was γ -Al 2 O 3 > δ -Al 2 O 3 > boehmite > α -Al 2 O 3 . Furthermore, a comparative study of leaching temperature demonstrated that elevated temperature favorably strengthened the thermodynamic driving force and greatly promoted the Al extraction. This study is of some theoretical significance for guiding the thermal activation and acid leaching of coal gangue. Graphical
研究领域:
矿物加工
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材料科学
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冶金学
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热力学
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产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
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2025
·Vol. 32
·期 5
·1079-1090
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IF 7.2
Li Xiang,Zhu Nengwu,Xi Yunhao,Li Fei,Zhang Pengfei
Secondary aluminum dross (SAD) is a rich source of recyclable aluminum but poses considerable risk due to its high AlN content. Therefore, thoroughly removing AlN is essential, but intricate aluminum components and expensive additives pose challenges to the process. In this study, waste sodium acetate is proposed as an environmentally friendly additive for completely removing AlN and enhancing the extraction of aluminum from SAD. Through the exothermic decomposition of NaAc, reactions can occur at 850°C. AlN removal efficiency reached 93.19% after sintering, whereas Al leaching efficiency in the subsequent leaching process reached 90.49%, which were 37.86% and 375.26% higher than the removal efficiency of the control, respectively. These favorable results were attributed to the comprehensive transformation of aluminum species. The formation of soluble phase Na 1.95 Al 1.95 Si 0.05 O 4 occurred during the destruction of the Al 2 O 3 layer surrounding AlN and the transformation of other aluminum components. AlN decomposed upon contact with NaAc. Therefore, this study utilizes the decomposition properties of NaAc to provide an efficient and environmentally friendly route for removing AlN and extracting Al from SAD.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Hongxia Fang,Chuncai Zhou,Shihai Xu,Jiaqian Shi,Yunhu Hu,Guijian Liu
Currently, the poor adsorption performance caused by the unsatisfactory pore size seriously restricts the further development of microporous nanosilica (MS). Herein, an excellent microporous nanosilica was constructed by preparing calcium silicate hydrate (CSH) support from the aluminum-extracted residue of coal fly ash and modifying it with different activating agents (H 2 SO 4 , HNO 3 , HCl, CH 3 COOH, KOH, NaOH and Na 2 CO 3 ). The results indicated that CH 3 COOH at 30 wt% was the optimal modifier, achieving a CO 2 uptake of 1.42 mmol/g at 298 K and 1.0 bar. Then the effects of synthesis parameters including mass fraction, liquid–solid ratio, temperature, and time on the adsorption capacity of CO 2 were further investigated. The obtained MSCp exhibited a high specific surface area (up to 505.71 m 2 /g), well-developed microporosity (0.085 cm 3 /g), and excellent CO 2 uptake (2.12 mmol/g at 273 K, 1.41 mmol/g at 298 K). Based on the study of kinetics, isosteric heat of adsorption (Qst), and situ diffuse reflectance infrared Fourier transformation spectroscopy (DRIFTS), the adsorption mechanism of MSCp was determined to be mainly physical adsorption. Besides, the excellent CO 2 /CH 4 selectivity of 20.91 (15/85, v/v) and 30.75 (50/50, v/v), CO 2 /N 2 selectivity of 53.79 (15/85, v/v) and 163.76 (50/50, v/v) were obtained from MSCp at 298 K and 1.0 bar. Finally, the binary gas breakthrough experiments and eight adsorption–desorption cycles confirmed the MSCp was suitable for selective adsorption of CO 2 in practical applications.
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
Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Xiangyu Li,Zhiqing Wang,Ru Feng,Jiejie Huang,Yitian Fang
If a large amount of fly ashes produced by coal-fired power plants was not treated harmlessly, it will pose a serious threat to the ecological environment. As one of the high-valued utilization technologies of fly ash, the technology of extracting aluminum from coal ash produces large quantities of waste residue after acid leaching nevertheless. It is an economic and environmentally friendly way to recycle alumina-extracted residue (AR) as solid sorbent to capture CO 2 . In this study, using AR as raw material, we synthesized PEI modified solid sorbents by novel “wet gel impregnation” method (WGI) to enhanced CO 2 capture. The effects of amine loading, adsorption temperature, and impregnation method on CO 2 adsorption capacity and kinetics were investigated by thermogravimetric analysis (TGA). On this basis, a possible double-layer adsorption model was proposed, i.e., the PEI adsorption layer on the outer surface of sorbents and the internal isolation layer. The ratio of the two layers changed with the variation in PEI loading and adsorption temperature, resulting in the difference of adsorption capacity. The maximum CO 2 adsorption capacity of 2.07 mmol/g was obtained under the amine loading of 40 wt% at 95 °C, and 100% CO 2 . Moreover, the stable adsorption capacity and high CO 2 selectivity were maintained in five repeated adsorption-desorption cycles.
研究领域:
环境科学
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材料科学
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化学工程
✓ 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）