SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Nian Zhang,Fujian Li,Kaibo Hu,Zhongzhi Wang,Haiyang Xue,Bangyu Fan,Xiangping Zhang,Haifeng Dong
As the associated element of ion-adsorbed type rare earth ores, aluminum ion (Al 3+ ) has a great influence on the purification of gadolinium ion (Gd 3+ ). In this paper, six carboxylic ionic liquids were synthesized with methyltrioctylammonium ([N1888] + ) as cation and carboxyl group as anion, and optimized for selective separation of Al 3+ /Gd 3+ . The extraction capability, separation factor, stripping property and recycling stability of the ionic liquid on the separation of Al 3+ and Gd 3+ were systematically investigated. In addition, the loaded Al 3+ can be totally stripped by 0.08 mol‧L −1 HCl solution. A particularly high separation factor of 923 can be obtained for removing Al 3+ from industrial GdCl 3 feed solution (762 mg‧L −1 Al 3+ and 146 g‧L −1 Gd 3+ ). The removal rate of Al 3+ was up to 98.69% and the recovery rate of Gd 3+ achieved at 92.47% by carboxylic ionic liquid ([N1888][C 7 H 11 O 2 ]) in one-step extraction. After 0.6 mol‧L −1 HCl solution stripping and 0.5 mol‧L −1 NaOH solution regenerating, the extraction efficiency of Al 3+ was only reduced by 3% after 5 cycles of organic phase. With the low acid and base concentration, it greatly reduced the chemical consumption and significantly the emission of high ammonia–nitrogen wastewater in industry. This work provides a low-carbon process for efficient removal of Al 3+ from industrial GdCl 3 feed by carboxylic ionic liquids.
研究领域:
化学工程
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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 Cleaner Production
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2019
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IF 6.395
Fujian Li,Yanliang Wang,Xiang Su,Xiaoqi Sun
Recycling schemes from rare-earth-containing scraps have been developed rapidly due to the increasing supply risk for rare-earth elements (REEs). This article aimed to reduce the ecological impact and reagent costs for separating and recycling REEs from scraps, i.e., spent ceria-based polishing powders and lutetium-based crystal waste. A simultaneous process was proposed using an industrial extractant Cyanex ® 572, which allowed efficient recycling of REEs from the wastes with less acid and alkali consumption than traditional hydrometallurgy process. Based on thermodynamic and kinetic analyses, common acid scrubbing was avoided by employing REEs scrubbing. Additionally, the alkali saponification, acid stripping and oxalic acid precipitation were substituted by one step of precipitation-stripping-saponification with ammonium fluoride which contained abundant F − in the solution with weak acidity. F − was easy to complex with REEs on the extractant as precipitate while NH 4 + bonded with anion of the extractant. Using this technique, the vast consumption of chemicals and million tons of wastewater in REEs industry may be avoided. Totally, the chemical consumption could be reduced over 80% and the wastewater was decreased more than 90%. REEs recovery yield also increased considerably using the novel process. Moreover, the ammonium fluoride was designed in containment system and was reused with no emission to the environment. This article provides a sustainable and efficient alternative process to REEs waste treatment industry.
研究领域:
冶金学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2013
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IF 2.816
Wenhua Wang,Yucui Hou,Muge Niu,Tong Wu,Weize Wu
Alkali-oxygen oxidation of coals to produce the high-value benzene polycarboxylic acids (BPCAs) is a potential substitute for the petroleum route in the future. However, the high alkali amount consumed in the process is a big obstacle for the practical application. In this work, bituminous coal , the preferential coal rank for this route, was oxidized at temperatures higher than that reported so far. The results show that, as the oxidation temperature increases, a gradually decreased amount of alkali and shortened reaction time are required to get the maximum yield of BPCAs, which remains about 41%. The distributions of BPCAs obtained from the high-temperature oxidation are very close to that of the traditional method. Excess alkali employed in the system can decrease the yield of BPCAs obtained, especially at high temperatures. The enhanced salting out effect by excess alkali concentration delays the diffusion of intermediates to the water phase, during which the mother structures for BPCAs are possibly over-oxidized to carbon dioxide . The high-temperature oxidation of bituminous coal drastically decreases the alkali consumed and improves the production efficiency of BPCAs, which is very important to the industrialization of this process.
研究领域:
化学工程
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煤化学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
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2024
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IF 15.8
Yu Han,Jiaxiang Ma,Dongqing Liu,Yan Yang,Tao Zhang,Min Wang,Daxin Liang,Liping Wen,Jun Ma,Wei Wang
Ion-sieve adsorbents are effective materials in practical applications for extracting liquid lithium. However, it is greatly suppressed in adsorption capacity and selectivity (Li/Mg) under natural near-neutral conditions of seawater or salt lakes, due to the interference of in situ released H+ and Mg2+ impurity. This paper proposes an adsorbent with a microenvironment-modulating function as a solution. The introduction of quaternary ammonium groups into the carrier accelerates the migration of H+, while preventing the diffusion of Mg2+ by electrostatic repulsion. Besides, it can also prestore OH–, effectively consuming the generated hydrogen ions in situ. Based on the rational design, the alkali consumption of the microenvironment-modulating strategy is dramatically reduced to 1/144 of the traditional alkali-adding method. Additionally, adsorption performance is significantly promoted under natural pH conditions, with a maximum 33 times higher separation factor (selectivity) and 4 times higher adsorption capacity than commercial ion-sieve adsorbents. This development indicates the feasibility of using microenvironment modulation for effective lithium extraction and inspires the development of next-generation high-performance adsorbents.
研究领域:
材料科学
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环境工程
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化学工程
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可持续能源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Yu Han,Yan Yang,Yuling Ma,Daxin Liang,Liping Wen,Jun Ma,Wei Wang
As lithium is the cornerstone of green energy development, it is crucial to realize a low environmental impact and efficient lithium extraction process. Ion-sieve adsorption is the most widely used method to extract liquid lithium resources, but this method is only efficient under alkaline conditions for H + and Mg 2+ competing adsorption. Conventional methods are often accompanied by the consumption of quantities of alkali, the generation of solid waste, and the acidification of liquid lithium resources. To address these issues, a selective ion-channel adsorbent was constructed. The composition comprises an ion sieve adsorbent and an organic carrier with a zwitterionic quaternary ammonium base group. This group storages OH - in situ, hinders H + diffusion, slows down Mg 2+ diffusion, and accelerates Li + diffusion by relying on the difference in binding energies, which reduces the competing adsorption and avoids acidification and solid waste generation. The saturated adsorption capacity (21.38 mg/g) and selectivity of the adsorbent are 4.7 and 24 times higher than that of conventional ion-sieve adsorbent under neutral conditions respectively. The dosage of alkali is 1/256 of the traditional method, the effluent remains neutral and no solid waste is generated. This study presents an environmental and effective adsorbent for lithium extraction.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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