Silicon
·
2020
·Vol. 13
·期 2
·531-541
·
IF 1.499
Li Feifei,Jiang Xuesong,Zuo Qiuxia,Li Jingwei,Ban Boyuan,Chen Jian
Iron is a major impurity in quartz sand and must be strictly removed in many applications. However, the iron removal rate in most of the conventional purification process is not high enough. In this study, a fast, low-energy consuming, environment-friendly and simple process for purifying quartz is demonstrated by a combination of microwave heating and ultrasound-assisted acid leaching treatment. Using the characteristics of selective heating of microwave, the micro-inclusions burst and generate cracks in the surrounding quartz matrix far below the α/β phase transition temperature, which enables removal of the impurities in the subsequent processing steps and reduces iron diffusion into the quartz matrix. Microwave process sequence, time, and temperature are all important factors, and appropriate parameters need to be explored. Ultrasound can assist acid leaching removal of Fe impurities through the cracks. Under optimized conditions, the iron content can be reduced to below 0.167 ppmw with one single purification pass.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD SCIENCE AND BIOTECHNOLOGY
·
2019
·Vol. 28
·期 5
·1349-1358
·
IF 0.888
Lin Jie,Shi Yuanxu,Dong Chunwang,Wang Xiaochang
The perceived aroma of oolong tea is primarily and directly affected by its infusion matrix, and the release persistence of headspace volatiles can better illustrate the persistent aroma. Headspace solid phase microextraction coupled with gas chromatography–mass spectrometry was performed to analyze the headspace constituents of oolong tea. The presence of the infusion matrix seemed to prevent the headspace release of certain odorants. The release of indole, nerolidol, and α -farnesene was also remarkably enhanced or depressed (2.70, 1.56, and 0.69-fold in tea infusion versus in dry leaves). Moreover, the amount of volatile species gradually decreased with increased water ratio. Eight odorants were determined to be stable and persistent during continuous infusion, whereas six were determined to be less persistent (gradually decreased or stopped releasing). The volatile dilution test further confirmed the persistent release of nerolidol.
研究领域:
食品科学
·
植物化学
✓ 已验证
DOI
PubMed
高影响因子
HYDROMETALLURGY
·
2024
·
IF 4.8
Qingfeng Zhou,Xiangdong Ma,Xunhui Xiong
This work proposes the roasting of amblygonite with calcium sulfate followed by water leaching to extract lithium and phosphorus. Various roasting parameters including roasting temperature, the mass ratio CaSO 4 /ore, roasting time as well as leaching parameters, such as the liquid/solid ratio, temperature and time, have been carefully investigated. The lithium extraction efficiency can be as high as 99.8% with a mass ratio of CaSO 4 /ore of 0.85 after roasting at 775 °C for 1 h and water leaching at a liquid/solid ratio of 3 mL/g at 100 °C for 2 h. The XRD analysis demonstrates that the fluoride in the amblygonite can be converted into Ca 5 (PO 4 ) 3 F and CaF 2 . Lithium in the leach liquor can be recovered as Li 2 CO 3 . Meanwhile, the phosphorus in the water leach residue can be recovered as FePO 4 with a high recovery of 96.6% after acid dissolution and precipitation, which can be further treated to produce LiFePO 4 .
研究领域:
矿物加工工程
·
无机化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL BIODETERIORATION & BIODEGRADATION
·
2024
·
IF 4.1
Weiqi Leng,Jingke Zhao,Minghao Wang,Jiayan Luo,Sheng He,Shengcheng Zhai,Jiangtao Shi,Islam Hafez,Xuefeng Zhang
This article explores the feasibility of rare earth element-tannin complexes as a wood preservative . The tannins (T) from Cercis glabra Pampan. are extracted, sulfonated (ST), and coordinated with lanthanum (La) elements to fabricate the complexes (La-T, and La-ST). Results show that two stable complexes, La-T and La-ST, are successfully formed by coordinating the La-ions with the phenolic hydroxyl groups in T and ST. Sulfonated tannins have a better adsorption capacity for lanthanum ions. The mass percentage of La in La-ST (36.50%) is higher than that in La-T (24.85%). The results of the white-rot decay test reveal that wood treated with La-T (1.98%) and La-ST (2.58%) preservatives has significantly lower weight loss rates compared to the untreated (28.94%). However, the brown rot decay test demonstrates that wood treated with La-T (62.68%) and La-ST (50.81%) only has slightly lower weight loss rates compared to the untreated (71.84%). Finally, the leaching of La-T and La-ST treated poplar wood was significantly lower than La self-treated ones. This novel approach can produce stable rare earth-wood preservatives and improve the wood's bio-durability and anti-leaching properties, thus remarkably enhancing the outdoor performance of modified wood products .
研究领域:
林产化学
·
木材科学与技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Yusufujiang Mubula,Mingming Yu,Hongju Gu,Lei Wang,Man Chen,Tingsheng Qiu,Guangjun Mei
Rare earth molten salt electrolytic slag (RMES) has emerged as a promising secondary resource for rare earth elements (REEs). This study introduces an innovative leaching technique for extracting REEs from RMES under atmospheric conditions, employing an alkali phase reconstruction method followed by an acid leaching process. Additionally, the external electric field was employed to enhance the reaction. Under the optimal reaction conditions: NaOH initial concentration of 70 wt%, NaOH-slag mass ratio of 4:1, temperature of 160 °C, current density of 1000 A/m 2 , reaction time of 90 min, stirring speed of 300 r/min, HCl concentration of 4 mol/L, liquid-solid ratio of 15:1, and leaching time of 20 min, the leaching efficiencies of Nd and Pr reach up to 99.21% and 99.14%, respectively. Phase analysis indicates that the rare earth fluorides transform into rare earth hydroxides, significantly enhancing their solubility in acid solution. The imposition of an external electric field leads to pronounced disruption of the RMES surface, thereby promoting the formation of stable reactive oxygen species in the alkaline medium. This facilitates the decomposition of fluorinated rare earths and hastens the phase reconstruction, resulting in an enhanced leaching process. The achieved leaching efficiency with an external electric field is 37% higher than that without an electric field.
研究领域:
冶金工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2022
·Vol. 29
·期 9
·1715-1721
·
IF 3.85
Dang Hui,Chang Zhidong,Zhou Hualei,Ma Sihang,Li Min,Xiang Jialing
The effective and low-temperature extraction of lithium from the pyrometallurgical slag of spent lithium-ion batteries (LIBs) remains a great challenge. Herein, potassium carbonate/sodium carbonate (K 2 CO 3 /Na 2 CO 3 ), which could form a eutectic molten salt system at 720°C, was used as a roasting agent to extract lithium from pyrometallurgical slag. Lithium was successfully extracted from the slag by K 2 CO 3 /Na 2 CO 3 roasting followed by water leaching. Theoretical calculation results indicate that the lengths of Li-O bonds increase after K + /Na + adsorption, resulting in the easy release of Li + from the LiAlSi 2 O 6 lattice after roasting with K 2 CO 3 /Na 2 CO 3 . Thermogravimetry—differential scanning calorimetry results indicate that the eutectic phenomenon of K 2 CO 3 and Na 2 CO 3 could be observed at 720°C and that the reaction of the slag and eutectic molten salts occurs at temperatures above 720°C. X-ray diffraction results suggest that Li + in the slag is exchanged by K + in K 2 CO 3 with the concurrent formation of KAlSiO 4 , while Na 2 CO 3 mainly functions as a fluxing agent. The lithium extraction efficiency can reach 93.87% under the optimal conditions of a roasting temperature of 740°C, roasting time of 30 min, leaching temperature of 50°C, leaching time of 40 min, and water/roasted sample mass ratio of 10:1. This work provides a new system for extracting lithium from the pyrometallurgical slag of spent LIBs.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2025
·
IF 10
Chenyu Wang,Han Zhou,Chaoyue Wu,Weibo Sun,Xiaohui Sun,Chao He
Hydrothermal carbonization combined with wet chemical methods for treating sewage sludge produce valuable hydrochar and phosphorus. However, further investigation is needed to optimize the balance among phosphorus recovery, heavy metal leaching, residual hydrochar utilization to enhance overall process benefits. In this study, acid leaching on hydrochar was conducted using HCl, H 2 SO 4 , citric acid at 0.1 – 1.0 M acid concentration for 10 – 1440 min, the liquid-to-solid ratio between 50 to 500 mL/g. Employing single-factor experiments, response surface methodology, various characterization techniques, the impacts of acid leaching on the leaching rates of phosphorus and heavy metals, along with residual rate and properties of the remaining hydrochar, were quantitatively assessed. The results indicate leaching parameters directly impact the phosphorus leaching rate. HCl and H 2 SO 4 achieve their corresponding maximum phosphorus leaching rate within 60 min at acid concentration 0.5 M, liquid-to-solid ratio 500 mL/g, while using citric acid requires 360 min. When H 2 SO 4 is used as the extractant, the corresponding maximum phosphorus leaching rate can be maintained within a wider leaching time and acid concentration range. A moderate acid concentration, prolonged leaching time, higher liquid-to-solid ratio lead to increased levels of heavy metal concomitant leaching. Compared to HCl and citric acid, using H 2 SO 4 as extractant results in lower heavy metal leaching and lower sensitivity to leaching parameters. The residual rates of hydrochar range from 59.3% to 77.3%, with H 2 SO 4 and HCl as extractant yielding higher residual rates than citric acid. The properties of the remaining hydrochar were altered by acid leaching, resulting in a decrease in specific surface area and pore number, but an increase in oxygen-containing functional groups and calorific value, which affects its subsequent utilization. Finally, based on the aforementioned results and potential process scenarios, the selection of optimal acid leaching parameters was discussed. The results provide reference for the selection of phosphorus recovery and resource utilization pathway based on sludge-derived hydrochar.
研究领域:
环境科学
·
资源与能源工程
✓ 已验证
DOI
高影响因子
CHEMICAL PAPERS
·
2018
·Vol. 72
·期 12
·2997-3003
·
IF 0.963
Guo Dongqing,Fu Likang,Wang Shixing,Zhang Libo,Peng Jinhui
A new purification method for molybdenum disulfide via NaNO 3 –HCl–HNO 3 synergistic leaching at 80 °C was developed. The effects of the concentration of NaNO 3 , HCl, and HNO 3 , and liquid–solid ratio and the leaching time on the purification of molybdenum disulfide were investigated by orthogonal array design methodology. The results of Taguchi method utilizing L 25 (5 5 ) orthogonal array indicated that the NaNO 3 concentration had the greatest impact on the purification of molybdenum disulfide. The optimum conditions for the purification of molybdenum disulfide were as follow: concentration of NaNO 3 = 2.5%, concentration of HCl = 11%, concentration of HNO 3 = 1.0%, liquid–solid ratio = 3, and the leaching time = 10 h. Under optimum conditions, the content of molybdenum increased from 55.1 to 59%, and the contents of iron, copper, lead, and calcium decreased from 0.35 to 0.21%, 0.027 to 0.008%, 0.054 to < 0.005%, and 0.27 to 0.035%, respectively. Based on molecular formula of molybdenum disulfide, the content of molybdenum disulfide increased from 91.93 to 98.44%. XRD and SEM indicated that this method removed only the impurities and did not affect the phase and particle size of molybdenum disulfide. The results show that the new purification method avoids the roasting process and will achieve the “green” production. The new method based on orthogonal array is effective for the purification of molybdenum disulfide via acid leaching.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Food Bioscience
·
2023
·
IF 5.2
Yuxin Huang,Ruyang Chen,Yulian Chen,Chi-Tang Ho,Aixiang Hou,Xilu Zhang,Mingzhi Zhu,Chunyan Zhang,Yuanliang Wang,Zhonghua Liu,Yu Xiao
Eurotium cristatum is a dominant fungus in the post-fermentation of Fu brick tea, however, its potential role in affecting the volatile profile and non-volatiles metabolites during the liquid-state fermentation of dark tea is not clear. In this study, dark tea was prepared by liquid-state fermentation with E. cristatum . A total of 51 volatile compounds were identified by HS-SPME-GC-MS, which mainly consisted of ketones, aldehydes, esters, and alcohols. There were 12 volatiles (ROAV >1) contributed to the overall aroma, including linalool, citral, methyl salicylate, etc. The overall flavor of tea infusion had been greatly improved after fermentation. The content of ester-type catechins , total phenols , total flavonoids , theaflavins, thearubigins, soluble sugars, and free amino acids decreased, while the content of theabrownins and soluble proteins increased. Meanwhile, the content of nonester type catechins and gallic acid increased and then decreased. The contents of various volatiles and metabolites change under the action of E. cristatum , coordinating to form a fermented dark tea infusion with mint, flower and fruit aroma and mellow and slightly astringent quality. The antioxidant activities showed a positive correlation with substances such as gallic acid and polyphenols. The results showed that the liquid-state fermentation with E. cristatum can effectively influence the flavor characteristics and antioxidant capacity of dark tea infusion.
研究领域:
食品科学
·
微生物学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Agronomy-Basel
·
2022
·Vol. 12
·期 11
·2907
·
IF 3.949
Changqing Li,Shuo Wang,Mengyu Sun,Dongxiao Li,Huasen Xu,Liangyu Zhang,Cheng Xue,Wenqi Ma,Zhimei Sun
Soil nutrient testing is an effective way to uncover soil nutrient status. However, the conventional testing method (CT method) and Mehlich 3 method (M3 method) demand long-time consumption, tedious testing steps, high testing cost, dangerous chemicals contained in extractant, etc. Therefore, it is important to develop a new rapid test method or improve the existing rapid test method of soil available nutrients. In this study, an improved Mehlich3 method (IM3 method) with the new combined extractant were developed and evaluated on the testing feasibility, precision, efficiency, and cost. The results showed that: (1) IM3 method avoided the usage of two hazardous chemicals, i.e., ammonium nitrate and nitric acid, which were difficult in purchase and storage but contained in the combined extractant of M3 method. (2) The correlation coefficients of available P, K, Fe, Mn, Cu and Zn in calcareous soil between M3 and CT, and between IM3 and CT methods all reached highly significant level. The correlation coefficient of available Zn between IM3 and CT method was significantly higher than that between M3 and CT method, and those of the other elements had not obviously changed. (3) The variation coefficients of available P, K, Fe and Cu determined by M3 and IM3 methods were all lower than those determined by CT method. The variation coefficients of available Mn and Zn determined by IM3 were 3.67% and 6.43%, which were slightly higher than those determined by CT method with 2.72% and 5.29%, but were lower than those determined by M3 method. (4) Under the premise of ensuring testing precision, IM3 method took only 6.3 min/piece for determining six elements, reducing testing time by 70.7% and 3.08% compared with CT (21.5 min/piece) and M3 (6.5 min/piece) methods, respectively. The testing cost of IM3 method was reduced by 26% and 61.2% compared with M3 and CT methods, respectively. In conclusion, IM3 method is an ideal rapid measurement method for the simultaneous determination of available soil nutrients in calcareous soil.Keywords:improved testing method for soil nutrients;extractant;testing precision;testing time;testing cost;calcareous soil
研究领域:
农业化学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2016
·Vol. 40
·期 4
·603-612
·
IF 0.832
Lu Zhang,Zong-Cai Tu,Hui Wang,Qing-Hui Wen,Zhi-Feng Fu,Xing Xie
Effects of dynamic high pressure microfluidization (DHPM), microwave, ultrasound, maceration and high temperature, on the phenolic acids and antioxidant activity of Artemisia selengensis Turcz (AST) were investigated. Microwave exhibited the best extraction efficacy on phenolic compounds and flavonoids with the content of 40.30 μg GAE/mg Extract, and 37.75 μg RTE/mg Extract, respectively. Microwave extract (MWE) also showed the strongest DPPH· and HO· scavenging ability (IC 50 value of 0.23 and 0.50 mg/mL, respectively), and reducing power (Ab 0.3 value of 0.23 mg/mL). Quinic acid, 3 caffeoylquinic acids (CQAs), 2 coumaroylquinic acids, 4 dicaffeoylquinic acids (diCQAs) were identified as the major phenolic acids in AST using HPLC-QTOF-MS/MS, and 3-CQA (63.71 μg/mL) showed the highest content followed by 1,5-diCQA (17.91 μg/mL) and 3,5-diCQA (13.50 μg/mL). MWE had the highest 3-CQA and diCQAs. While, high temperature could promote the degradation of diCQAs, 3- and 4-caffeoyl are more liable to decompose as compared with 1- and 5-caffeoyl. Practical Application Over production of reactive oxygen species (ROS) in body will induce various chronic diseases. AST is an underutilized vegetable with many health benefits. This research indicates that AST possessed appreciating antioxidant activities and abundant phenolic acids, it is could be a potentail antioxidants resource and for prevention of chronic diseases associated with ROS. It also suggested that microwave could be a promising method for extracting the antioxidants in AST. Therefore, this research could lay a foundation for the high-value application of AST in food, health care and natural therapy industry, and provide some methodological references for the development of antioxidants in AST.
研究领域:
药理学
·
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Nutrition
·
2022
·
IF 6.59
Zhang Chaohua,Gu Fenglin,Hu Weicheng,Wu Guiping,Chen Weijun,Dong Conghui,Niu Zhiqiang
In this study, the yield, content of piperine, and antioxidant activity of pepper oleoresin obtained with the methods of maceration, ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and ultrasound-MAE (UMAE) were analyzed, and the microstructure of pepper residue was observed. For the yield and piperine content, the UMAE method had the best extraction capacity among the four methods. While, the oleoresin obtained with maceration had the highest total phenolic content, and the antioxidant activity of the oleoresin obtained by maceration was higher than that of the extracts acquired by UAE, MAE, and UMAE, and a high positive correlation was observed between the antioxidant activity and total phenolic content of the oleoresin obtained by these extraction methods. The ideal parameters for UMAE were an 80-mesh particle size and a 1 g/10 mL solid–liquid ratio. The kinetic parameters and models of the UMAE extraction process were also compared using first- and second-order models. The second-order kinetic equation with the lowest root mean square deviation and highest adjusted correlation coefficient proved to be more suitable for describing the extraction kinetics of pepper oleoresin. This study showed that UMAE is a fast, efficient, and cost-effective technique for the extraction of green pepper oleoresin.
研究领域:
食品科学
·
化学工程
·
生药学
✓ 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）