JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2023
·
IF 2.6
Shuyang Shi,Baozhong Ma,Shuang Shao,Yongqiang Chen,Chengyan Wang
An original technology named HNO3 pressure leaching has been proposed by our team to leach Al from coal gangue and fly ash. Although the preliminary separation of Al and Fe had been achieved during leaching, a small amount of Fe impurity was still unavoidably dissolved into the leach liquor. To obtain pure Al2O3 during subsequent pyrolysis, it is imperative to synchronously remove Fe3+ during the crystallization of Al(NO3)3·9H2O. Herein, the phase equilibria of the Al(NO3)3–Fe(NO3)3–H2O(−HNO3) system at 25–40 °C and 0–8.12 mol kg–1 of HNO3 molality were investigated. The results indicated that the ternary system was a simple cosaturated type consisting of an immutable point, two univariate curves, and two crystallization regions. Notably, the solubility and crystallization region of Al(NO3)3·9H2O were barely impacted by acidity, while the opposite was true for Fe(NO3)3·9H2O. This finding was instructive for the crystallization of Fe(NO3)3·9H2O from the liquor with high Fe and low Al. Moreover, a high crystallization yield could be obtained at low temperatures. Finally, an appropriate crystallization procedure was provided. This study is expected to provide basic data and theoretical support for the crystallization and separation of mixed nitrates containing Al and Fe.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
HYDROMETALLURGY
·
2020
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IF 3.338
Shaohua Wu,Wenju Tao,Yanchen Zheng,Youjian Yang,Jiangyu Yu,Jingbo Cui,Yu Lu,Zhongning Shi,Zhaowen Wang
A hydrometallurgical process was developed to extract lithium from a spent lithium-containing aluminum electrolyte, reduce the stacking of spent aluminum electrolyte, and recover the valuable elements. In this study, we extracted lithium from an electrolyte using the following three steps: 1) leaching with HNO 3 − Al(NO 3 ) 3 , 2) neutralizing the leachate obtained in the first step, and 3) precipitating the lithium carbonate. A lithium extraction efficiency of 88.0% could be achieved after a leaching time of 6 h, at a leaching temperature of 80 °C and an Al/F molar ratio of 1:6. During the process of neutralization, Al 3+ and F − was precipitated as Al 2 ((OH) 0.46 F 0.54 ) 6 (H 2 O). The obtained Li 2 CO 3 with a high purity of 98.8%.
研究领域:
冶金学
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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
Materials Today Communications
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2023
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IF 3.8
Jiaming Li,Youjian Yang,Wenju Tao,Zhaowen Wang,Jiangyu Yu,Jiaxin Yang,Zhibo Liu
As China's aluminum electrolysis industry expanded its production capacity, it produced a large amount of bath materials– cryolite based molten salt, which is not utilized fast enough and piled up in aluminum factories. It is of great significance to find a proper way to process the accumulated bath materials. Through the method introduced in this paper, aluminum fluoride can be produced from cryolite-based electrolyte and fed back into the aluminum electrolysis cell as a necessary additive. This method includes four steps: Calcination of crystalline aluminum nitrate with cryolite. Cryolite and crystalline aluminum nitrate are mixed and preheated. The main chemical reaction that occurs in this step will produce sodium nitrate (NaNO 3 ), β-aluminum fluoride (β-AlF 3 ), chiolite (Na 5 Al 3 F 14 ) and the aluminum hydroxyfluoride hydrate (AHF). After calcination, the products are washed with water to separate soluble NaNO 3 from the other products. The insoluble products obtained after washing are calcined with ammonium bifluoride to convert AHF into AlF 3 . The mixture obtained after preheating is then washed with an aqueous solution of aluminum salt (such as Al(NO 3 ) 3 ) to remove Na 5 Al 3 F 14 . Aluminum fluoride of high purity is obtained in the end. Calcination step is the most important among the four steps. The effects of calcination temperature (85 – 135 ℃) and molar ratio of crystalline aluminum nitrate to cryolite (0.5 – 2) on the conversion rate of cryolite were studied. The experimental results show that the highest conversion rate of cryolite can reach 97.03%. Through SEM, EDS , ICP and other analysis methods, it was found the final products contained more than 98.8 wt% aluminum fluoride and less than 0.4 wt% sodium, and the average particle size of aluminum fluoride is approximately 15 – 20 µm.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2023
·Vol. 13
·期 5
·1335-1344
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IF 5
Mei Hong,Yuxiang Liu,Haidi Sun,Liping He,Junkai Zhu,Huixian Wang,Shifa Wang,Licheng Li
Lignocellulosic biomass is a potential sustainable feedstock to replace fossil fuels. Utilization of lignocellulosic biomass in a green and effective way is of great significance for sustainable development. The direct, one-pot, one-step catalytic conversion of glucose to 2,5-diformylfuran is a challenging task. In this work, Al(NO3)3 has been heterogeneously supported on porous carbon derived from Na-lignosulfonate or a mixture of Na-lignosulfonate and Na-polystyrene sulfonate via ice-templating, mild pyrolysis (350 and 450 °C) and H+ exchange techniques to obtain bifunctional carbocatalysts (Al(NO3)3@LH or Al(NO3)3@LH–PH). The catalysts were characterized by Fourier transform infrared (FT-IR), pyridine adsorption infrared (Py-IR), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS) and Brunauer–Emmett–Teller (BET) analyses. A novel one-step cascade method of producing DFF directly from glucose through the binary catalyst Al(NO3)3@LH or Al(NO3)3@LH–PH with AlBr3 in 99% DFF yield without the need for a strong oxidant is described. Mechanistic studies show that the cascade conversion of glucose involves isomerization, dehydration and successive Kornblum-type oxidation. Moreover, the catalysts could be reused in consecutive runs, exhibiting a slightly lower activity in the synthesis of DFF from glucose.
研究领域:
化学工程
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催化
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可再生能源
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绿色化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）