ADVANCED POWDER TECHNOLOGY
·
2025
·
IF 4.2
Jingjing Zou,Yiping Sun,Shuo Liang,Zhongrui Shi,Guanghe Li,Chunbin Guo
This study introduces a novel process for recovering Al 2 O 3 from coal fly ash (CFA), utilizing potassium persulfate (K 2 S 2 O 8 ) as an activator, and explores the decomposition behavior of both crystalline and amorphous alumina phases within CFA. The experiment involved mixing K 2 S 2 O 8 with CFA in K 2 S 2 O 8 /Al 2 O 3 molar ratios ranging from 0.5:1 to 4:1, followed by calcination at varying temperatures and durations to optimize alumina extraction. The results indicated that the alumina extraction efficiency of 91 % was achieved with a molar ratio of 3:1 (K 2 S 2 O 8 /Al 2 O 3 ), calcination temperature of 405 °C, and reaction time of 2 h. X-ray photoelectron spectroscopy, scanning electron microscopy, and reaction kinetics were employed to analyze the reaction mechanism. The findings revealed that K 2 S 2 O 8 preferentially reacted with the amorphous alumina phase, leading to the breakage of Al–O–Si bonds. The release of SO 2 and O 2 during the reaction further facilitated the breakdown of the crystalline phase by disrupting aluminum–oxygen tetrahedra. Simultaneously, the silicon-oxygen tetrahedra decomposes and forms SiO 2 gel layer, wrapping the remaining aluminum oxygen octahedron, thus preventing further alumina extraction. This study contributes to a deeper understanding of the decomposition behavior of crystalline and amorphous alumina phases in CFA during sulfate roasting. The findings provide a theoretical foundation for refining alumina recovery processes and offer significant improvements to existing sulfate roasting methods.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Material Cycles and Waste Management
·
2023
·Vol. 25
·期 4
·2485-2497
·
IF 3.1
Wei Jie,Liu Zhanwei,Yan Hengwei,Yang Wanzhang
Herein, fluorine fixation, nitrogen removal, and the alkaline solution recovery of alumina were studied using calcium-based high-temperature soda roasting. In addition, the effects of roasting conditions, dissolution conditions, and additives (carbon alkali and calcium salt) on fluorine fixation and alumina recovery were studied. The results show that when the roasting temperature was 1100 ℃ and the roasting time was 2 h, the dissolution temperature was 80 °C, while the dissolution time was 20 min. The ratio of soda to dross was 1.0, and 30 wt% CaCO 3 had been added as a fluorine fixing agent. The Al extraction rate from aluminum dross (AD) reached 86.21%, the denitrification rate reached 99.54%, the concentration of soluble fluoride ion was reduced to 0.111 g·L −1 , and the fluoride fixation rate was 75.04 wt%. CaF 2 is the main component of the leaching residue, which can be added as an insulation material for electrolysis. Alkaline oxidation roasting and calcium-based fluoride fixation are effective methods to separate aluminum, fluoride, and nitrogen. This study provides a new method for the safe and efficient utilization of AD.
研究领域:
化学工程
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环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
RARE METALS
·
2018
·Vol. 38
·期 1
·1-13
·
IF 1.5
Liu Qi,Wang Wen-Qiang,Yang Yue,Liu Xue-Gang,Xu Sheng-Ming
Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al 2 O 3 . The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an alkaline leaching process under the conditions of 5 mol·L −1 sodium hydroxide, a liquid/solid ratio of 20 ml·g −1 , a temperature of 160 °C and a reaction time of 4 h. In the leaching residue, no difficult leaching compound is found and cobalt and nickel are enriched, both of which are conducive to the subsequent metal recovery step. The reaction order of aluminum leaching is 0.99. This reaction fits well with the interfacial chemical reaction model, and its apparent activation energy is calculated as 45.50 kJ·mol −1 . Subsequently, γ-Al 2 O 3 with a high specific surface area of 278.3 m 2 ·g −1 , a mean size of 2.2 μm and an average pore size of 3.10 nm is then regenerated from the lixivium, indicating its suitability for use as a catalyst carrier. The recovery and regeneration of alumina from spent catalysts can not only significantly contribute to the total recycling of such hazardous spent catalysts but also provide a new approach for the preparation of γ-Al 2 O 3 with a high specific surface area using spent catalysts as the aluminum sources.
研究领域:
化学工程
·
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jiaxin Yang,Wenju Tao,Jiaming Li,Lingyu Kong,Shaohua Wu,Jingui He,Zhaoshun Liu,Yu Sun,Zhaowen Wang
Low energy consumption and environmentally friendly recycling methods can extract high-added value and high-demand elements from retired waste fluorinated aluminum electrolytes (RWE-Al), which is crucial for alleviating resource shortages and environmental hazards. This study aims to develop a method for recovering fluorine and aluminum from RWE-Al through calcium leaching transformation combined with acid leaching. Compared to the traditional high-temperature roasting transformation and high-concentration alkali-metal-salt leaching process, this new process only involves one step of low-temperature leaching, purification of fluorine, carbonization of excess calcium, and evaporation extraction of aluminum, avoiding the generation of high energy consumption and secondary hazardous waste (F-containing liquid/ residue). Fluorine and aluminum are effectively separated and purified with extraction rates exceeding 96%. The effects of leaching temperature, CaO addition coefficient, liquid–solid ratio, and leaching time on the leaching process were systematically studied. The effects of acid concentration, liquid–solid ratio, time, and temperature on the acid-leaching process were also investigated. In summary, the comprehensive utilization of RWE-Al by this new process has proved to be feasible.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xiaopeng Jin,Manxing Huo,Qifeng Wei,Xiulian Ren
The separation of aluminum and manganese from mineral leach solutions has been a challenge at present and has attracted great interest. In this paper, the effects of different extractants on aluminum recovery as well as the effects of the concentration of the most suitable extractant, extraction temperature, initial pH and organic phase/aqueous phase ratio on the recovery of aluminum were investigated. The results showed that for chromite recovery solution(CRS) with an initial aluminum concentration of 0.1221 g/L, S-NA at 0.25 mol/L exhibited good selectivity and extraction efficiency for aluminum, and was able to separate aluminum from other elements and recover it easily for secondary use without scrubbing. The extraction mechanism of aluminum in sulfuric acid medium was investigated through various analyses including the combination of energy and bond length calculations, electrostatic potential (ESP) theory calculations, IGMH analysis, process chemistry analysis, and thermodynamic equilibrium species calculations. These analyses showed that Al(III) was distributed in the recycling solution in the form of AlSO 4 + and had strong interactions with naphthenate ions, and that the combination of AlSO 4 + with the naphthenate ions(R − )’s formed the stable complex molecule AlSO 4 R. The study provides a feasible path for the recovery of aluminum in CRS and is of guiding significance for the theoretical study of aluminum in sulfuric acid media.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
·
IF 8.4
Teng Zhang,Jingmin Yan,Zhengchen Li,Hongyang Wang,Peiwei Han,Shufeng Ye
Red mud (RM) is a strongly alkaline solid waste produced during the production of alumina from bauxite. China's RM stockpile exceeds 1 billion tons, with an annual output of over 100 million tons. However, the comprehensive utilization percentage is less than 10%, and the rest are stored around alumina plants, which are severely burdening land and the surrounding environment. This study proposes a combined roasting process, which combines soda roasting with medium-temperature magnetization roasting, to synchronously convert minerals in RM into magnetite and soluble aluminate, to achieve the goals of iron concentrate upgrading and aluminum recovery. Iron concentrate with of yield of 72.52 wt%, total iron (TFe) concentration of 63.84 wt%, iron recovery of 93.47 wt%, and aluminum concentration of 2.53 wt%, and the aluminum product with the Al 2 O 3 concentration of 99.49 wt% were obtained under the optimized process parameters. Four pathways to iron concentrate upgrading that reduce the aluminum concentration during combined roasting are proposed based on the non-isothermal kinetic analysis and phase evolution results. These results can provide theoretical support for the comprehensive utilization of iron and aluminum in RM.
研究领域:
冶金工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）