SEPARATION SCIENCE AND TECHNOLOGY
·
2021
·
IF 2.475
Xuekai Zhang,Kanggen Zhou,Qingyuan Lei,Yan Xing,Changhong Peng,Wei Chen
A new approach was developed using NaH2PO4 as the stripping agent for Fe stripping from Fe-loaded Aliquat 336 during rare-earth elements recovery from red mud leachate. Owing to the strong coordination between Fe3+ and H2PO4‒, Fe mainly exists as FeH2PO42+ at [H2PO4‒] higher than 0.5 M, which can be readily stripped. The results showed a maximum Fe stripping efficiency of 95.5% under optimal condition. Moreover, the extraction capacity of the extractant after stripping was comparable to that of fresh extractant, and decreased only by 2% after 6 cycles, indicating the robustness of this approach for Fe stripping and extractant regeneration.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Yue Ma,Chao Hu,Yanru Jin,Honggang Zhen,Junhu Wu,Lin Yang
Typical industrial solid waste, red mud, contains significant amounts of ruthenium, an important secondary resource for valuable metals. This study aimed to investigate the efficient leaching of ruthenium from red mud by comparing the leaching efficiency of different inorganic acids. The results indicated phosphoric acid exhibited the highest leaching effect compared to sulfuric acid, nitric acid, and hydrochloric acid. The influences of leaching temperature, phosphoric acid concentration, leaching time, liquid-solid ratio, and stirring speed on the leaching of ruthenium were examined. Under the conditions of a leaching temperature of 90 °C, a phosphoric acid concentration of 5 mol/L, a leaching time of 6 h, a liquid-solid ratio of 12:1, and a stirring speed of 500 rpm, ruthenium leaching efficiency of 93.53%. SEM-EDS characterization of red mud before and after leaching confirmed that most of the ruthenium is transferred into the liquid phase, while a small portion remains in the leach residue. X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectra analyses also revealed significant changes in the mineral structure of red mud during leaching, along with the presence of recoverable iron, aluminum, and calcium in the leach solution. Furthermore, the shrinkage kernel model described the kinetics of ruthenium leaching. The leaching process of ruthenium is primarily governed by chemical reactions at temperatures of 40–60 °C, with an activation energy of 57.36 kJ/mol, as expressed by the kinetic equation 1 − ( 1 − α ) 1 3 = e ( 17.49 − 57360 RT ) × t . At temperatures of 70–90 °C, the leaching process is controlled by chemical reactions and solid film diffusion, with an activation energy of 39.80 kJ/mol, as expressed by the kinetic equation ( 1 / 3 ) ln ( 1 − α ) + [ ( 1 − α ) − 1 3 − 1 ] = e ( 11.22 − 39800 8.314 T ) × t . These findings provide innovative insights into the recovery of ruthenium resources and the comprehensive utilization of red mud.
研究领域:
冶金学
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yanwei Cao,Dilong Chen,Yaowei Wang,Huibing Shi,Baolin Feng,Chungu Xia,Yuxiao Ding,Lin He
The development of new application scenarios for the red mud, a huge by-product from the aluminum manufacture, has become urgent because of the increasingly stringent demands of environmental protection. Herein, a very simple and sustainable approach to the design of a synergistic catalytic system for the direct oxidative cross-coupling of alcohols and amines to (un)symmetric imines by physically mixing MnO x and red mud is presented. With the catalysis of active red mud, the synthesis of imines over MnO x can achieve an excellent (>98%) yield at 60 °C, air as oxidant for 8 h Without this catalysis, the imine yield reaches only 25%. The red mud clearly assists the reaction, resulting in a 4 ∼ 10-folds higher increase over reactions using only MnO x . From detailed experiments and characterizations, the synergistic effects of the extraordinary performance of this catalytic system were confirmed to be a combination of the reactivity of MnO x in the oxidation of alcohols and the enhancement by the active red mud in the condensation of aldehydes and amines. This work demonstrates a facile strategy for revival of the hazardous red mud. It could turn “waste” into wealth and greatly promote the catalytic applications of red mud.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Ting Shi,Mengxin Guo,Hongcheng Gao,Yi Wang,He Li,Mingming Wu,Dongyuan Cheng,Yi Han,Dejin Wang
Tetracycline as a common emerging pollutant has received widespread attention worldwide. In this paper, RMSSx:y composite pellets were prepared by an annealing process to adsorb tetracycline (TC) from wastewater using red mud (RM) and steel slag (SS) as raw materials. The RMSS5:5 composite pellets prepared with a mass ratio of 5:5 at a calcination temperature of 900 °C exhibited excellent adsorption properties. The experimental data were analyzed using Langmuir, Freundlich, and Temkin adsorption models. The equilibrium data fitted both the Langmuir and Freundlich models well. Kinetic adsorption data were analyzed using the quasi-primary kinetic model, the pseudo-secondary kinetic model, the intraparticle diffusion model, and the Boyd model. The maximum adsorption capacity of RMSS5:5 for TC reached 183.78 mg/g. Thermodynamic studies revealed the exothermic and spontaneous nature of the adsorption process. The adsorption mechanism involved the complexation of Fe, Ca with TC, hydrogen bonding, electrostatic interaction, and physisorption. In addition, RMSS5:5 possessed excellent magnetic responsive properties and cycling performance. This study successfully prepared an efficient and cost-effective adsorbent with two industrial solid wastes, which has great potential for TC removal from wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2025
·
IF 9.1
Wang Dechao,Yang Xinyu,Huang Haihan,Wu Kaiyue,Zheng Jie,Yao quan,Lin Jian,Huang Yuanbo,Liu Peng,Wang Duo,Ye Yueyuan,Zheng Zhifeng
Biomass, as a renewable resource, holds great significance in its conversion into valuable chemicals or fuels, representing a crucial avenue for its utilization. Nevertheless, catalytic pyrolysis currently faces constraints, demanding further enhancements in both the selectivity of target products and the recyclability of catalysts. Herein, we reported an innovative in-situ combined with ex-situ catalytic pyrolysis strategy by using red mud loaded with cobalt (Co/RM) and activated carbon (AC) as the catalyst for this combined catalytic pyrolysis system. By optimization of process conditions, the selectivity of furans was further improved significantly. The results showed that with a combined catalytic system constituted of Co/RM and Co/RM + AC, under conditions of a pyrolysis temperature of 400 °C, a catalytic temperature of 500 °C, and a mass ratio of catalyst to raw material of 20:1, the selectivity of furans can be increased to 80.1 %. Remarkably, this combined catalytic system exhibits excellent catalytic activity for furans production even after 20 cycles of operation. Moreover, the established combined catalytic system is capable of converting tobacco, bamboo, and wood into furans with more than 100 % increasement. These results suggest that this novel strategy harbors broad application prospects and has the potential to catalyze more efficient exploitation of biomass resources.
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Dazhong Yang,Manyu Shi,Juan Zhang,Atsushi Sasaki,Masatoshi Endo
Arsenic-contaminated red mud (As-RM) is a hazardous waste with limited recycling approaches. Generally, through reductive roasting and magnetic separation, RM could be transformed into Fe-rich concentrate for Fe resource recovery. However, due to the poor thermostabilization of As species, reductive roasting of As-RM would cause severe As volatilization pollution together with high As leaching risks from heated residue. Herein, a novel johnbaumite-based As thermostabilization strategy is developed for clean Fe resources recycling from As-RM. We found that in the presence of Ca(OH) 2 , the As species in As-RM could be immobilized as thermostable and insoluble johnbaumite (Ca 5 (AsO 4 ) 3 OH) at 900 °C, effectively enhancing the As thermostability and insolubility. Introducing 1.5% Ca(OH) 2 into As-RM suppressed the As volatilization ratio from 60.3% to 15.7% during reductive roasting. Meanwhile, the As leaching concentration of the reduced residue was reduced to < 100 µg/L, thus satisfying the Japanese wastewater discharge standard. A concentrate with approximately 67.5% total iron grade was obtained from As-RM through this clean reductive roasting and magnetic separation. Overall, the approach introduced in this work effectively reduces the As diffusion pollution deriving from As-RM thermal reduction, which could contribute to hazardous As-RM reutilization, clean Fe resources recovery, and As pollution mitigation.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS ES&T Engineering
·
2022
·
IF 0
Dazhong Yang,Zheting Chu,Xuezhen Feng,Qiuyue Ge,Ranhao Wang,Juan Zhang,Shangying Li,Renji Zheng,Wenfei Wei,Shuping Yi,Hong Chen
Both alkaline heavy metal (HM) contaminated red mud (RM) recycling and Cr(VI) polluted soil remediation are severe hazardous environmental problems. Herein, we developed a novel integrated approach to neutralize and stabilize the hazardous RM via the introduction of Ca2+ and Cl– dual ions. When 3% CaCl2·2H2O is added, the pH of RM is reduced from 11.0 to 8.9, and the Pb, Cr, Zn, Cu, and As leaching concentrations from RM are suppressed lower than the environmental standards of China and the World Health Organization (Pb, Cr, Zn, Cu < 0.50 mg/L; As < 10 μg/L). Detailed mechanism studies reveal that the pH neutralization is attributed to the novel OH– flocculation effect ascribing to Ca2+ charge neutralization and Cl– promoted proton neutralization. Furthermore, as the pH decreases, the HM adsorption capacity of RM is enhanced, achieving stable HM immobilization. The treated RM can be further employed to remediate Cr(VI) contaminated soil (Cr concentration 570 ppm; treated RM weight percentage in soil 5.0%), which can suppress 56.0% Cr mobility in soil and 68.4% bioaccumulated Cr in the harvested vegetables. Overall, this work demonstrates an ecofriendly “waste-to-soil remediation” strategy to solve both the solid waste and soil pollution problems.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Binyuan Gao,Chongran Sun,Tao Yang,Haina Cheng,Hongbo Zhou,Yuguang Wang,Zhu Chen
Red mud is a highly saline and alkaline solid waste generated in alumina refinery, which entails dealkalization for safe disposal and valorization. Herein, Trichocomaceae sp. K-2, a novel fungus isolated from marine sediment , was used for the simultaneous dealkalization of red mud and recovery of valuable metals. The fungus demonstrated robust growth at high salinity (45 g/L NaCl), good tolerance to high pH (up to 12), and capability of utilizing low-cost substrates derived from lignocellulosic biomass. Both structural and free alkali can be removed by Trichocomaceae sp. K-2 to achieve a significantly lower minimum pH (<4) in a considerably short timeframe (<16 days), and the alkali removal efficiency as high as 94% was attained. Moreover, concomitant leaching of valuable Nd, Sc and Y from red mud during dealkalization was feasible. Physical disintegration and chemical erosion by the secreted organic acids were responsible for the effective dealkalization, as well as leaching of valuable metals. This study sheds lights on how marine microorganisms can be harnessed to the green disposal of red mud, and provokes the exploration of more robust and versatile marine microbes for the sustainable and cost-effective management of other highly saline and alkaline solid waste.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 1.6
Muhammad Sarfraz,Yang Li,He Yang,Lijun Jin,Haoquan Hu
Mercury (Hg 0 ) emission from coal-fired industrial plants poses severe threats to ecosystem sustainability and human health, urging the development of novel and cost-effective adsorbents to treat industrial flue gas. Herein, the modification of industrial residual red mud (RM) through the impregnation of hydrogen halides (HH) and its adsorption characteristics for removing elemental mercury from combustion flue gas was reported. Experimental investigation of HH-modified RM reveals that the hydrogen iodide (HI)-modified RM with a concentration of 1.5 M had a maximum Hg 0 removal efficiency of 98%, whereas hydrogen bromide (HBr) 1.5 M modified RM had a maximum Hg 0 removal efficiency of 90%. The effect of various parameters, such as reaction temperature and halide concentrations, were also found to be influential for the adsorption efficiency of the modified RM. Moreover, it is important to highlight the chemisorption characteristics of HI-modified RM, which significantly enhances the efficiency of the removal process. The Hg 0 removal efficiency increases with the increase in HI concentration (1.5 M @ 93%) with an optimal reaction temperature of 140°C. Furthermore, the maximum Hg 0 removal attained with a change in NO concentration was 98% at 200 ppm. However, increasing the SO 2 concentration reduces the efficiency of RM for removing Hg 0 in simulated coal combustion flue gas. The pseudo-second-order model ( R 2 = 0.98) accurately describes the adsorption of in kinetic investigations, indicating a chemisorption mechanism. This analysis of the chemisorption mechanism highlights the efficiency of halide-modified industrial solid waste, which has the potential to be used in the design of economical and innovative adsorbents for reducing environmental pollution. The present study employed specific reaction parameters such as reaction temperature, halide loading contents, and different flue gas compositions, which had not been extensively explored.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 84
·53622-53630
·
IF 3.108
Changming Li,Hong Zeng,Pingle Liu,Jian Yu,Feng Guo,Guangwen Xu,Zhan-guo Zhang
The development of new routes for the utilization of red mud (RM) waste is very urgent due to its huge accumulation and potential environmental harm. By taking advantage of its Fe–Al–Si–Ti composition and excellent plasticity, we developed a ball milling and acid–base neutralization method to reuse the RM waste as Fe-based denitration catalysts. The resulting RM catalysts demonstrate excellent catalytic activity and stability with >90% NO conversion above 400 °C in the presence of SO2 and H2O, which is even much better than that of a commercial V–W–Ti catalyst. Characterization data reveal that our treatment eliminates poisonous alkaline metal elements and increases dispersion of RM particles, making the RM active for denitration reactions. The formation of ferric sulfate species with more reducible Fe3+/Fe2+ active sites by a SO2 activation method can further enhance the denitration activity. Moreover, NH3-TPD and in situ IR results demonstrate that the NH3-SCR reaction over the RM catalyst follows the Eley–Rideal mechanism at high temperature and the increased absorption of NH3 for alkaline metal-eliminated or SO2-activated samples accounts for its high DeNOx efficiency. The demonstrated feasibility for reusage of the RM as DeNOx catalyst has promising industrial prospects for its extremely low cost, no toxicity, and high efficiency.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2021
·
IF 4.837
Bin Li,Caizhu Chen,Yuwei Zhang,Le Yuan,Hong Deng,Wenmin Qian
In order to solve the problem of chrome slag returning to yellow and Red Mud accumulating in large amounts, this study proposes to use Red Mud and chromite ore process residue instead of clay to make glass-ceramics, and seal chromium, so as to achieve the purpose of waste control by waste and high-valued of final product. The Red Mud (RM), Chromite ore process residue (COPR) and silicon dioxide were homogenized in ethanol and fired at 1200 ℃ for 2 h. The results of XRD and SEM-EDS show that part of chromium enters the lattice, and the rest is wrapped in silicate glass . The leaching toxicity test data of solidified samples showed that the leaching concentrations of hexavalent chromium and total chromium were below the detection limit. In the process of sintering, solidification and preparation of glass-ceramics, Red Mud is not only used as one of the raw materials of glass-ceramics, but also plays the role of fluxing agent and nucleating agent, which greatly reduces comprehensive energy consumption and the production cost of glass-ceramics. This study provides a new way to solve the environmental problems caused by RM and COPR.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2020
·Vol. 10
·期 1
·1-18
·
IF 3.998
Wang Yanting,Gong Shengying,Li Yazhuo,Li Zhang,Fu Jie
In this study, a novel, sustainable and efficient ceramsite substrate of constructed wetlands (CWs) were prepared for tetracycline (TC) removal by employing bentonite (Ben) and red mud (Rm) as the main materials and pine sawdust (Ps) as the additive. The optimal parameters for Ben/Rm/Ps ceramsite preparation were obtained via orthogonal and one-factor experimental designs, and the optimal parameters were presented as follows: mass ratio of Ben: Rm: Ps = 4:1:0.9, preheating temperature = 240 °C, preheating time = 20 min, calcining temperature = 1150 °C, and calcining time = 14 min. The properties of Ben/Rm/Ps-op ceramsite (obtained at the optimal condition) were first analyzed, including XRD and SEM, and demonstrated a microporous structure with some crystal strength components. Neutral condition and higher temperature were indicated conducive to improve the TC removal efficiency, while coexisting ions (Na + or Ca 2+ ) showed adverse effect for TC adsorption by Ben/Rm/Ps-op. In addition, adsorption kinetics and isotherm could be well described by the second-order kinetics and linear isothermal model, respectively, which suggested chemisorption and multilayer adsorption thickness increased infinitely. The theoretical maximum TC adsorption capacity of Ben/Rm/Ps-op at 20 °C reached up to 2.5602 mg/g. In addition, Ben/Rm/Ps-op could effectively remove TC as the CWs substrate under a dynamic flow condition. Further, Ben/Rm/Ps-op exhibited high reusability capability and stability for TC removal, and the adsorption amount still remained for 2.13 mg/g ( C 0 = 80 mg/L) after three consecutive cycles.
研究领域:
环境科学
·
水处理技术
✓ 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）