PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2025
·
IF 7.8
Yehao Huang,Jia Yao,Bowen Yu,Longyu Zhang,Xiangyu Song,Weijun Peng
Chalcopyrite and molybdenite present challenges in flotation separation due to their similar floatability. In this study, ozone micro-nano bubble was employed to oxidize chalcopyrite and molybdenite, altering their surface properties to facilitate them separation via flotation. The flotation results demonstrated a significant reduction in the recovery of chalcopyrite through ozone micro-nano bubble oxidation, while molybdenite remained unaffected. The concentrates with the Mo recovery remained steady at 84 % and Cu recovery below 9 % were achieved in flotation experiments of the artificially mixed ores with various mass ratios of chalcopyrite and molybdenite. Analysis of the results from X-ray photoelectron spectroscopy (XPS), zeta potential , and contact angle measurements indicated that the surface of chalcopyrite was oxidized to form metal oxides and hydroxides after ozone micro-nano bubble oxidation, thereby decreasing its floatability. In contrast, the oxidation products of molybdenite dissolved in the pulp, preserving its original surface and floatability. Additionally, experimental results confirmed that micro-nano bubbles exhibited superior oxidation effectiveness and rate than those of conventional bubbles. In summary, ozone micro-nano bubble oxidation presented a promising green alternative to traditional depressants for the efficient separation of copper and molybdenum sulfide ore.
研究领域:
矿物加工工程
·
冶金工程
·
表面化学
·
资源回收
·
环境友好技术
·
胶体与界面科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Youru Yao,Na Mi,Cheng He,Huan He,Yong Zhang,Yongcai Zhang,Li Yin,Jing Li,Shaogui Yang,Shiyin Li,Lixiao Ni
The dissolved hexavalent chromium (Cr(VI)) in natural water system poses a significant risk for public health and the environment. Nanoscale ferrous sulfide (FeS) has been widely used to treat soils, sediments, groundwater, and natural waters contaminated with Cr(VI), but the reactivity of FeS can be significantly reduced due to its easy agglomeration and therefore decreased the remove rate of the dissolved Cr(VI). To overcome this problem, the present study used humic acid (HA) to modify FeS in order to reduce its agglomeration and increase stability. Results showed that the HA modified FeS (HA-FeS) had good stability and reduced FeS agglomeration. The hydrodynamic diameter of HA-FeS was between 235 and 241 nm, which was much smaller than that of the unmodified FeS. The maximum removal quantity of Cr(VI) by HA-FeS was 7.74 and 2.35 times higher that of HA and the unmodified FeS, respectively, and the maximum removal quantity of HA-FeS was 675.03 mg/g. Further, HA-FeS performed better efficiency in removing the dissolved Cr(VI) with high or low concentration. With an increasing concentration of Ca 2+ and Mg 2+ , the efficiency of HA-FeS to remove Cr(VI) showed a decreasing trend. The removal mechanism of Cr(VI) mainly relies on the reducibility of Fe 2+ and S 2− . XPS and XRD measurements further revealed that 95.03% of Cr(VI) was converted to Cr(III) (FeCr 2 O 4 , Cr(OH) 3 and Cr 2 O 3 ), and another 4.58% of Cr(VI) was adsorbed by HA-FeS. Therefore, this study demonstrated an efficient method to improve the nano-FeS stability and reactivity for the rapid repair of Cr(VI) contamination in natural water.
研究领域:
环境科学
·
水处理
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Ying Quan,Qinfu Liu,Kuo Li,Hao Zhang,Liang Yuan
Due to the fine granularity of CG with the dissemination of non-graphite minerals, highly efficient purification of natural coaly graphite (CG) by low-cost, low-energy consumption and low-pollution methods remains a challenge. In this study, a novel and efficient electrochemical method is demonstrated for purifying natural CG. The electrochemical purification is carried out in a mixed electrolyte containing 0.5 M (NH 4 ) 2 SO 4 and 10% HF with an optimum potential sequence starting at + 2.5 V for a few minutes followed by a short burst of + 5 V. The CG purification mechanism is proposed based on the experimental results. There are three main factors, namely, the type of the graphite anode, the electrolyte and the applied voltage are critical for effectively electrochemical purification. It is interesting to find that the main purified products are graphene mixed with graphite aggregates at a yield of 68%. Raman analysis indicates that the purified CG has fewer structural defects than the natural CG after removing the non-graphite minerals. Moreover, the XPS and FTIR analysis demonstrate that no other functional groups are grafted onto the parent graphite during this purification process. In comparison with the electrolyte only containing HF, the adding of 0.5 M (NH 4 ) 2 SO 4 in the HF electrolyte could reduce the amount of HF by more than 50%, which cuts the cost and alleviates the impact on the environment.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jieliang Wang,Xianbo Fang,Zhao Cao,Wenqiang Zhu,Jianguo Cui,Qizheng Qin,Peng Wang,Aiqing Wang,Burdonov Alexander Evgenievich
In this study, ultrasonic treatment was introduced to improve the activation of octyl hydroxamic acid (OHA) as a collector, enhancing the flotation of bastnaesite. The mechanism of OHA activation by ultrasonic treatment and its role in strengthening adsorption of octyl hydroxamic acid on bastnaesite surface were investigated via flotation experiments combined with solution chemistry calculations, conductivity tests, bubble-particle wrap angle (BPWA), atomic force microscopy (AFM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and molecular dynamics simulations (MDS). Solution chemistry calculations and conductivity measurements indicated that ultrasonic treatment enhanced the dissociation of OHA molecules significantly, generating more active OHA − anions and thereby improving OHA activation. The increased BPWA confirm enhanced the adhesion of bastnaesite to bubbles following OHA adsorption. AFM and SEM-EDS analysis showed that the adsorption amount of OHA on the surface of bastnaesite increased after ultrasonic treatment. XPS analysis demonstrated that the chemical adsorption of ultrasonic-treated OHA on the bastnaesite surface is enhanced, which improves the hydrophobicity and flotation performance of bastnaesite. This also confirmed that ultrasonic-treated OHA produced more active OHA − anions. MD simulations indicated that as the proportion of OHA − increased, the adsorption and spreading ability of OHA collector clusters on the bastnaesite surface were enhanced, repelling water molecules from the bastnaesite surface. Consequently, the hydrophobicity of the bastnaesite surface increased, further strengthening its flotation performance.
研究领域:
矿物加工工程
·
表面化学
·
浮选化学
·
计算材料科学
·
资源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2024
·
IF 3.4
Yu Wang,Bin Zhou,Jingjie Guo,Tao Liu,Yu Yang,Bing Li,Jiaojiao Yang,Yue Peng,Jianjun Chen,Wenzhe Si,Junhua Li
Developing high-performance mercury removal catalysts is essential for addressing atmospheric mercury pollution. Notably, conventional mineral adsorbents are ineffective for high-temperature flue gases (>300 °C). In this study, confinement catalysis was utilized to modify CuMn 2 O 4 . Under the chlorine-free catalytic condition, the temperature window of T 95 was widened by 150 °C (for 50–400 °C) toward high-temperature. Mechanistic studies suggest that nanoconfinement effects significantly improve the catalytic performance. Molecular oxygen adsorption and activation capacity were dramatically enhanced, as demonstrated by NAP-XPS. The plentiful grain boundaries effectively adjust the defect species and electronic structure of the catalysts in favor of Hg 0 catalysis, whereas the porous structure improves the reactant adsorption properties.
研究领域:
环境科学
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Chunlei Zhang,Ping Wu,Guojuan Liu,Zhigao Zhu,Gaofeng Zeng
Direct oxidation of methanol to high value oxygenated chemicals on V2O5/TiO2 based catalysts is a green alternative to the commercial methods. But the V–Ti based catalysts are challenged by the relatively low reactivity. Herein, we demonstrated a facile and practicable strategy to directly fabricate hollow structure VOx/TiO2 nanofibers (VTO-HNF) through the coelectrospinning and calcination method. The effects of V/Ti ratio on the structure, the surface chemistry and methanol oxidation performance were investigated in detail. VTO-HNFs with appropriate V/Ti ratio have hierarchical structure, large surface area, uniform nanoparticles, narrowed grain sizes, and high dispersions of vanadium. Moreover, both the oxidation properties and the acidities of the catalyst were enhanced due to the high content of surface V4+. The VTO-HNF catalysts featured excellent activities and reliable stability for the selective oxidation of methanol to methyl formate (MF) and dimethoxymethane (DMM). The MF yield reached 90% at 150 °C, which is comparable with the noble metal based catalysts. In situ NAP-XPS investigations suggested that the variable valence of vanadium was involved in the oxidation of methanol.
研究领域:
材料科学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
Journal of Materials Research and Technology-JMR&T
·
2018
·
IF 3.398
Bo Feng,Jinxiu Peng,Wei Guo,Guodong Luo,Wenpu Zhang,Huihui Wang
The separation of scheelite and calcite by froth flotation is difficulty as these two minerals have similar physicochemical characteristics. To solve this problem, the role of carboxymethyl chitosan in the flotation separation of scheelite from calcite has been studied and the depression mechanism has been discussed. Micro-flotation tests show that carboxymethyl chitosan has strong depression effect on calcite and the depression effect decreased with the increase of pH. However, its depression effect on scheelite is weak. A concentrate with WO 3 grade of 65.21% and WO 3 recovery of 77.48% can be achieved in the mixed minerals flotation when carboxymethyl chitosan was used. The adsorption tests show that carboxymethyl chitosan has adsorbed on the calcite surface and the adsorption amount increased with the increase of added amount. The adsorption mechanism of carboxymethyl chitosan on calcite surface was analyzed through the X-ray photoelectron spectroscopy (XPS) tests and the results revealed that carboxymethyl chitosan adsorbed on calcite surface mainly through chemical interaction.
研究领域:
矿物加工
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 14
·4624-4636
·
IF 6.177
Yi Yang,Weixin Qian,Haitao Zhang,Zhonghao Han,Hongfang Ma,Qiwen Sun,Weiyong Ying
FeMnxZr and FeMnxZr2Na catalysts prepared by coprecipitation and impregnation methods were applied to investigate the promoting effects of Zr on iron-based catalysts for high-temperature Fischer–Tropsch synthesis (HTFT). Ar physisorption and TEM demonstrated that Zr-promoted catalysts have a larger BET surface area and larger pore volume, which are more conducive to the distribution of active phases. Zr promoted the dispersity of iron particles and reduced the grain size of iron particles, resulting in the improvement of the FTS activity. The CO-TPD and MES results revealed that the introduction of Zr promoted the dissociative adsorption of CO, thereby promoting the formation of the active phase χ-Fe5C2 while suppressing the formation of ε′-Fe2.2C and further improving the FTS activity and the selectivity to C2=–C4= in the hydrocarbon distribution. However, the addition of an excessive amount of Zr caused the excess ZrO2 to cover the surface of the active site, inhibiting the CO dissociative adsorption and the formation of χ-Fe5C2, resulting in a decrease in the CO conversion and the selectivity to C2=–C4=. The XPS and H2-TPR results proved the interaction between Fe2O3 and ZrO2. And the Fe–ZrO2 interaction inhibited the coke deposition and aggregation of the Fe species, as confirmed by XRD and TEM, respectively. The FeMn5Zr2Na catalyst exhibited the highest C2=–C4= selectivity of 34.4% at a CO conversion of 96.3%. And FeMn5Zr2Na displayed the highest production of light olefins (441.6 g h−1 kgCat−1), which was significantly higher than FeMn2Na (162.2 g h−1 kgCat−1).
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
RADIOCHIMICA ACTA
·
2023
·Vol. 111
·期 12
·895-907
·
IF 1.8
Xiaoyu Yin,Peng Wu,Yufan Zhao,Shilong Shi,Jun Liu,Feize Li,Jiali Liao,Ning Liu,Yuanyou Yang,Tu Lan
The U(VI) sorption behavior on dolomite was systematically investigated in a dilute carbonate solution using batch technique. The distribution coefficients ( K d ) increased with the increasing time and temperature, but decreased with the increase of initial U(VI) concentration and ionic strength. As the initial pH increased from 2.0 to 10.5, the K d values first increased and then decreased, mainly due to the transition from electrostatic attraction to repulsion caused by the changes in U(VI) species. The sorption process was well-described by pseudo-second-order kinetic and Freundlich isotherm models, and was spontaneous, endothermic, heterogeneous, and pH-dependent. In the presence of HA/FA, at low pH, more HAs/FAs were adsorbed on dolomite surface, providing more sorption sites for the positively charged U(VI) species, and promoting the U(VI) sorption. At high pH, more HAs/FAs were dispersed in solution, encapsulating the negatively charged U(VI) species in aggregates, and inhibiting the U(VI) sorption. The promoting and inhibiting effects of HA on the sorption process are obviously stronger than FA. XPS spectra indicated that the surface ‒OH and CO 3 2− on the hydroxylated dolomite and the –OH groups in HA/FA may be involved in U(VI) sorption. The results reported here provide valuable references for further understanding U(VI) migration in geological media.
研究领域:
环境科学
·
地球化学
·
表面化学
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2025
·
IF 6
Linna Han,Zixu Wang,Wanfang Feng,Qing Xia,Yucun Niu,Liyan Liu
Background The enrichment of sugar phosphates (SPx) from complex biological samples was of significant importance for elucidating their roles in physiological and pathological processes. However, the detection of SPx faced numerous challenges due to the high structural similarity among its isomers, its extremely low abundance within cells, the complexity of biological samples, and the inefficiency and cumbersome nature of traditional enrichment methods. Therefore, there was an urgent need to develop an efficient enrichment technique, leveraging the advantages of magnetic separation to achieve precise detection of sugar phosphates in biological samples. Results A novel magnetic material, Fe 3 O 4 @UiO-66-Br, was synthesized for efficient and convenient enrichment of SPx in biological samples. The material exhibited a high specific surface area (225.08 m 2 /g) and strong magnetism (33.61 emu·g −1 ). Only 600 μg of Fe 3 O 4 @UiO-66-Br was required to completely adsorb five types of SPx within 4 min. The adsorption process was pH-tolerant and can be accomplished simply by standing. Kinetic, thermodynamic, and isotherm studies revealed favorable adsorption properties, characterized as spontaneous and endothermic monolayer chemisorption. Mechanistic studies using XPS, FT-IR, and DFT identified multiple interactions, including coordination, hydrogen bonding, and electrostatic interactions. The analytical protocol featured a wide linear range (0.01–10000 ng/mL), low detection limits (0.002–0.01 ng/mL), high precision (RSD<13.21 %), and accuracy (80.05 %–116.41 %). Significance The protocol was successfully applied to real blood samples, demonstrating the potential of magnetic MOFs for SPx adsorption and detection. This novel material and protocol provided an efficient approach for enriching and detecting trace SPx in complex biological matrices, facilitating further studies on their roles in physiological and pathological processes.
研究领域:
分析化学
·
材料科学
·
生物化学
·
纳米技术
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Song He,Junqing Zhu,Hongliang Sheng,Jiayi Tang,Tao He,Jinfeng Ji,Yajun Huang
The existence of TC residues in the environment and the resultant development of opposition mechanisms constitute a serious menace to both ecological systems and human health. In the present study, UiO-67-bpy-X gels were prepared by the introduction of H 2 bpydc ligands and acetic acid modifiers, followed by a systematic evaluation of their TC adsorption capabilities. Characterization results revealed that UiO-67-bpy-2.4 gel displayed raised specific surface area (1953 m 2 g −1 ) and a graded porous structure. When conditions were optimized, the material manifested a maximum TC adsorptive capacity of 404.1 mg g −1 , outperforming the performance of most reported adsorbents. The kinetic modeling and adsorption isotherm analyses implied that chemical adsorption constituted the dominant uptake pathway. The adsorptive mechanism was further analyzed by XPS, FT-IR, and DFT calculations, which can be attributed to the synergistic effects of metal coordination, electronic interaction, hydrogen bonding, and π-π interaction. Furthermore, the material exhibited good structural stability, retaining 85.945 % of its original adsorptive capacity after six cycles. These findings suggested that UiO-67-bpy-2.4 gel held significant promise as environmental remediation materials, offering high adsorptive capacity and ease of recycling, thereby presenting a novel approach to addressing TC contamination.
研究领域:
环境科学
·
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Ze Li,Yidan Fu,Lina Han,Pengfei Zheng,Xiaoyuan Zeng,Peng Dong,Jing Feng,Yingjie Zhang
The insufficient d-electron density in V metal atoms limits O2 dissociation, constraining the kinetics and activity of the oxygen reduction reaction and the oxygen evolution reaction in VN-based catalysts. Herein, Co dopant was employed to modulate the electronic characteristics of the d-orbitals and associated free energy of VN, thereby further enhancing its catalytic activity. XPS and XANES spectra revealed that Co atoms replaced V and strongly bonded with neighboring N atoms, effectively regulating the local electronic structure. DFT analysis show that the Co doping strategy effectively regulates the adsorption/desorption equilibrium of oxygen reduction reaction intermediates through d-electron transfer to V atoms, while significantly lowering the activation energy barrier of the rate-determining step. Electrochemically, V0.95Co0.05N/NC/C achieved a low bifunctional index (ΔE = 0.78 V), with a half-wave potential for the ORR of 0.83 V and an OER overpotential of 380 mV at 10 mA cm–2. In Zn-air batteries, it achieved a high specific capacity (708.98 mAh gZn–1) and retained 88% initial voltage after 280 h cycling, demonstrating robust stability for practical applications. This study presents a doping strategy to modulate d-band centers in transition metal nitrides for energy conversion devices.
研究领域:
电化学
·
材料科学
·
能量转换
·
催化
·
纳米技术
·
电池技术
✓ 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）