POWDER TECHNOLOGY
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2020
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IF 4.142
Xuesong Jiang,Jian Chen,Mengnan Wei,Feifei Li,Boyuan Ban,Jingwei Li
The purity of quartz particles obtained by crushing the same quartz is different. Poly (propylene glycol) bis (2-aminopropyl ether) (PEA) was used to separate quartz sand particles of different purity by flotation . Through flotation experiments combined with XRD , ICP , FT-IR, and XPS , the collection performance and adsorption principle were studied. Froth flotation results demonstrate that particles with higher purity can be more readily floated. Batch flotation results indicate that the first froth product (F1) has the highest purity and its removal rates of Al, K and Na reached 84.6%, 80.7% and 84.1%. The total impurity content (Al, K, Na) of F1 (448 ppmw), F2 (579 ppmw) and F3 (972 ppmw) is lower than the Feed (2717.4 ppmw) and their mass proportion is greater than 25%. XPS analyses confirm that the impurities are mainly enriched on the fracture surface. Consequently, the crushing-classification mechanism and the PEA adsorption model have been proposed.
研究领域:
矿物加工工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yu Xie,Guoming Huang,Yujun Wang,Zhengren Yan,Xin Wang,Juan Huang,Mingtang Gao,Weiyang Fei,Guangsheng Luo
The synthesis of piperacillin is very sensitive to the mixing effect and the pH of the system. Because of poor micro-mixing and imprecise pH control in the ampicillin chloride method using the traditional reactor, the impurity content of piperacillin does not meet the production standard. Therefore, a novel three-feed membrane dispersion microreactor was proposed and used to synthesize piperacillin, in which ampicillin was first mixed with 4-ethyl-2,3-dioxo-1-piperazine carbonyl chloride (EDPC) and then mixed with ammonia water under rapid and intense mixing conditions. The process of ampicillin circulation and slow addition of the EDPC also contributed to stabilizing the pH value. The effects of the distance between the ammonia feed and the EDPC feed, pH, reaction temperature, EDPC ratio, and circulation flow rate on the content of piperacillin and impurities were investigated. The piperacillin content of the condensation solution reached ~94.90% within 10 min under the optimal conditions in the microreactor, but the content only reached 91.06% in 60 min in the traditional tank; more importantly, the content of the key impurities D and E decreased from 0.340% to 0.080%, and 0.176% to 0.035%, respectively. Subsequent processes were carried out to obtain the final piperacillin product, where the average yield was around 93.99%; the purity was generally above 99.7%; the content of impurity D was generally less than 0.1%, and the content of impurity E was less than 0.05%, meeting the guidelines of the pharmacopoeia and antibiotic impurity.
研究领域:
制药工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2019
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IF 3.45
Meng Liu,Yong Yang,Yuquan Wei,Yajie Li,Heng Zhang,Xuejian Liu,Zhengren Huang
High-purity SiC materials have been used in semiconductor processes due to their excellent properties. However, they are difficult to densify without sintering aids. In this work, dense and high-purity SiC ceramics have been obtained by pressureless solid-state-sintering with ultra-low contents of sintering additives. The amount of residual B, C and O in the high-purity SiC ceramics was less than 0.15 wt%, respectively, and the total content of other impurity elements (such as aluminum , magnesium, calcium, iron, etc.) was less than 0.015 wt%. Finally, the purity of the as-prepared SiC ceramics was more than 99.5 wt%.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Bin Du,Xingming Huang,Anzhe Wang,Yiran Liu,Yuan Cheng
Ceramic powders with low oxygen content are highly demanded in monolithic ceramics. In this work, a series of medium-/high-entropy ceramic (HEC) particles, including (Zr 0.25 Ta 0.25 Nb 0.25 Ti 0.25 )C, (Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2 W 0.2 )C, (Zr 1/6 Ta 1/6 Nb 1/6 Ti 1/6 W 1/6 Hf 1/6 )C (Zr 1/7 Ta 1/7 Nb 1/7 Ti 1/7 W 1/7 Hf 1/7 V 1/7 )C, and (Zr 1/8 Ta 1/8 Nb 1/8 Ti 1/8 W 1/8 Hf 1/8 V 1/8 Mo 1/8 )C, were successfully fabricated by the polymer-derived ceramic (PDC) route. The structure evolutions of the precursor demonstrated that HEC particles obtained at 1800 °C possessed a single phase and rock-salt structure. All the samples had the similar microstructures (hillock structure) and a low oxygen impurity content (less than 2.00 wt%). The results also demonstrated that the as-obtained HEC particles had a disordered distribution of elements from nanoscale to microscale. This work proved a new method to fabricate the HEC powders with low oxygen impurity content and the HEC precursors for further obtaining the nanofibers or ceramic matrix composites .
研究领域:
材料科学
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陶瓷工程
✓ 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）