Article
Engineering, Chemical
Neslin Dogan, Murat Koksal, Gorkem Kulah
Summary: The objective of this study was to understand the gas axial mixing behavior in conical spouted beds operating with both low-and high-density particles. Experimental data showed that the axial dispersion coefficients increased with superficial gas velocity and were higher than fixed beds, lower than fluidized beds, and in the same range as cylindrical spouted beds. Gas convective transport was found to be relatively more important for light particles compared to heavy particles.
Article
Mechanics
Somnath Santra, Suman Chakraborty
Summary: The study demonstrates that controlling the axial oscillations can regulate the rate of transverse migration of droplets, and under the influence of an electric field, it is possible to achieve an increase in migration rate and reversal of lateral migration direction.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Environmental
Jose A. Lara-Ramos, Jennyfer Diaz-Angulo, F. Machuca-Martinez
Summary: A novel approach based on high turbulence zones was investigated to minimize mass transfer limitation in ozonation and catalytic ozonation processes. Using a modified flotation cell (MFC) as a reactor, the study achieved complete caffeine degradation and mineralization under the best operating condition, showing enhanced ozone mass transfer coefficient by increasing the stirring rate in MCF. The study also identified hydroxyl radical as a key species for caffeine degradation and mineralization in catalytic ozonation.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
Yiming Ji, Ajuan Song, Chao Li, Yijun Cao
Summary: Experimental study showed that bubble size was positively correlated with the chamber volume and orifice size, while a nonlinear relationship was observed with plate thickness. Moreover, flotation recovery decreased with increasing bubble size when changing the sparger configuration.
Article
Engineering, Chemical
Lisha Dong, Liguang Wang
Summary: This study investigates the impact of using oscillatory air supply in electrolyte solutions on improving graphite flotation kinetics, demonstrating that this method can increase the flotation speed of graphite without relying on traditional freshwater or organic reagents.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Review
Geochemistry & Geophysics
Guangsheng Zeng, Yangge Zhu, Wei Chen
Summary: In recent years, there has been a growing interest in applying rheology to the grinding and flotation treatment of finely disseminated ores. Slurry rheology, which is the comprehensive effect of inter-particle interactions, has the potential to play a significant role in interpreting the flowing and deforming phenomena in mineral processing. However, the influential mechanism of rheology in mineral grinding and flotation has not been fully determined, making it difficult to discover the underlying mechanism for enhancing processing efficiency. This paper reviews the current application and importance of rheology in fine mineral processing and proposes potential research directions in the field.
Article
Geochemistry & Geophysics
Annukka Aaltonen, Thi Minh Khanh Le, Eija Saari, Olli Dahl, Benjamin Musuku, Aleksandra Lang, Sakari Hiidenheimo, Richard Dixon
Summary: The pressure to save water in mineral processing is increasing due to factors such as water scarcity, stricter environmental legislation, limitations on wet tailings management, and increased demands for social licenses. Closing the water loops is necessary for sustainable mineral processing and can lead to improved recovery of valuable minerals. Flotation tests showed that the performance of nickel flotation improved after water purification by dissolved air flotation (DAF), likely due to a reduction in metal hydroxides and fine-grained silicate mineral particles in the process water. A feasibility study indicated that DAF treatment of process water can bring economic benefits at a concentrator plant.
Article
Green & Sustainable Science & Technology
Yi An Lim, I. M. S. K. Ilankoon, Meng Nan Chong, Su Chern Foo
Summary: This study aims to improve the growth of microalgae and enhance their CO2 capturing ability. By designing different gas spargers and studying their mixing performances, it was found that customised sintered metal spargers achieved higher mixing performances. These findings are important for the scale-up studies of photobioreactors and the realization of the circular bioeconomy concept.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Engineering, Chemical
Daowei Wang, Qi Liu
Summary: This study investigated the effect of aggregation/dispersion behaviors of fine hydrophilic particles on their entrainment in batch flotation, finding that in the presence of high dosage of corn starch or corn dextrin, fine hematite was primarily recovered into froth through entrainment rather than true flotation. This research provides evidence for the feasibility of the proposed two-stage aggregation/flocculation flotation concept for fine and ultrafine mineral particles.
MINERALS ENGINEERING
(2021)
Article
Engineering, Chemical
Pedro Silva Aires, Artin Afacan, Qi Liu, Vinay Prasad
Summary: This study proposed a new approach to measure the bubble size distribution, bubble mean diameter, Sauter mean bubble diameter, and gas holdup in an air/water two-phase system bubble column using a double-sensor conductivity probe. The results were compared and calibrated with bubble images taken by a digital camera, showing good agreement between the two techniques. The same conductivity probe was used in an air/water/solids three-phase system, where it captured the change in bubble dynamic behavior but was more challenging due to the presence of solids. In conjunction with the VisioFroth commercial package, the probe demonstrated the dynamic evolution of mineralized bubbles in a flotation process.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Energy & Fuels
Junyu Wang, Hangil Park, Chun Yong Ng, Liguang Wang
Summary: This paper presents the experimental results of flotation of a coking coal sample in highly saline water without any organic chemicals using an oscillatory air supply. The results show that changing the air supply pattern from steady to oscillatory significantly improves the recovery of combustibles, and there is little difference in the flotation performance using different oscillatory air generation devices.
INTERNATIONAL JOURNAL OF COAL PREPARATION AND UTILIZATION
(2022)
Article
Chemistry, Multidisciplinary
Chul-Hyun Park
Summary: Mixing in a flotation column significantly impacts the performance, particularly for coarse particles. The use of an axial dispersion model is suitable for accurately estimating rate constants.
APPLIED SCIENCES-BASEL
(2021)
Article
Geochemistry & Geophysics
Pengbo Chu, Ronghao Li, Mark Lepage, Kristian Waters
Summary: This study focuses on the impact of electrolytes on bubble break-up, revealing that an increase in electrolyte concentration results in larger bubbles produced through break-up, contrary to common observations. Additionally, it is found that electrolytes affect bubble break-up by altering the capillary wave on the bubble surface, different from the mechanism of surfactants.
Article
Engineering, Chemical
Rasoul Panjipour, Mohammad Karamoozian, Boris Albijanic
Summary: This paper discusses the relationships between bubble size distributions, gas holdups, interfacial area of bubbles and flotation kinetics by changing four factors: air velocity, solid percentage, frother dosage, and particle size. The results demonstrate that the solid percentage particularly affects gas holdups, which are directly proportional to the interfacial areas of bubbles. The knowledge about bubble size distributions and gas holdups are required to explain the flotation kinetics at different flotation conditions.
MINERALS ENGINEERING
(2021)
Article
Engineering, Chemical
F. Capponi, A. Azevedo, H. Oliveira, J. Rubio
Summary: This study found that injecting micro and nano bubbles into the rougher column flotation pilot plant can enhance the recovery of Nb2O5. For the fine sample, the Nb2O5 recovery increased by 1.4% with the injection of bubbles. For the ultrafine sample, the Nb2O5 recovery increased by 4.8% and the concentrate grade improved by 30% with the injection of bubbles.
MINERALS ENGINEERING
(2023)
Article
Energy & Fuels
Hangil Park, Liguang Wang
Summary: The inability to measure residual frother concentrations in real time has created challenges for flotation process control in the reuse of process water in flotation plants. This study upgraded the formulation and analysis procedure to improve the measurement sensitivity and demonstrated the potential of the method through methyl isobutyl carbinol (MIBC) concentration measurement in an industrial coal flotation circuit.
INTERNATIONAL JOURNAL OF COAL PREPARATION AND UTILIZATION
(2023)
Article
Metallurgy & Metallurgical Engineering
Hangil Park, Changzhi Bai, Liguang Wang
Summary: Froth flotation is a widely used particle separation process in the resource industry. The mobility of the froth phase significantly affects the performance of the flotation process. In this study, a simple method using a web-camera and a convolutional neural network (CNN) model was developed to monitor froth mobility by classifying images based on motion blur. The trained CNN model accurately classified froth images into three categories of mobility and showed good agreement with results analyzed using commercial software. The method has potential application for indicating flotation performance.
MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW
(2023)
Article
Metallurgy & Metallurgical Engineering
Bingyu Yang, Chun Yong Ng, Liguang Wang
Summary: This study demonstrates that adding acoustic sound can improve the efficiency of froth flotation. The results show that sound can significantly increase the flotation recovery in different particle size ranges and achieve better results at lower reagent dosages.
MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW
(2023)
Article
Engineering, Chemical
Yejin Lee, Hangil Park, Yevgen Matviychuk, Daniel J. Holland, Liguang Wang
Summary: This study extends the previously developed frother concentration analysis technique based on solid phase extraction process and cryogen-free benchtop NMR. It demonstrates the accurate quantification of widely used flotation frothers, even in the presence of residual flotation collectors and inorganic electrolytes. It also determines frother concentrations in blends and background chemicals. This technique has the potential for real-time on-site measurement and is easy to operate and maintain.
MINERALS ENGINEERING
(2022)
Article
Engineering, Chemical
Chun Yong Ng, Bingyu Yang, Hangil Park, Liguang Wang
Summary: This study experimentally investigated the effect of low-frequency acoustic sound on foam stability. The results showed that within certain ranges of sound frequencies and amplitudes, as well as different surfactant concentrations and gas velocities, the equilibrium foam height increased. Increasing sound amplitude or gas velocity also expanded the range of sound frequency that led to stabilization. This versatile method can improve foam stability.
MINERALS ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Changzhi Bai, Hangil Park, Liguang Wang
Summary: Solid bowl centrifuges are widely used in industrial applications for solid-liquid separation tasks. However, there is limited knowledge about the effects of operational variables on the dewatering performance. In this study, a simulation investigation was conducted to explore the effects of various process parameters on solids recovery, providing insights into the discrepancies in experimental findings.
Article
Engineering, Chemical
Fahed Javed, William B. Zimmerman, Tahir Fazal, Ainy Hafeez, Maria Mustafa, Naim Rashid, Fahad Rehman
Summary: A new heterogeneous catalyst was developed by modifying a metal-organic framework with biomaterials and integrating it with microbubble mediated mass transfer technology. The catalyst achieved high conversion and reaction rate, and showed good stability.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Engineering, Chemical
Yueyi Pan, Ghislain Bournival, Stoyan I. Karakashev, Bingyu Yang, Liguang Wang, Seher Ata
Summary: The growing complexity of mineralogy and environmental considerations requires mineral concentrators to maximize the synergistic effect of reagent mixtures and salts on flotation performance. This paper explores the stability of thin liquid films formed from frother solutions in the presence of a collector and an electrolyte. The study finds that adding potassium amyl xanthate (PAX) significantly improves the stability of the films, while the presence of salt decreases their stability. The film behavior is affected more by the presence and concentration of salt than by PAX.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Lisha Dong, Liguang Wang
Summary: This paper investigates the gas dispersion in a laboratory scale bubble column with different electrolyte solutions and varying ionic strengths and air flow rates. It is found that oscillatory air supply at a certain frequency and amplitude can improve gas dispersion compared to steady air supply, with the degree of improvement varying depending on the electrolyte type and concentration and air flow rate. Additionally, a cooperative effect of electrolyte addition and oscillatory air supply on gas dispersion is observed, with a significant decrease in the bubble size.
MINERALS ENGINEERING
(2023)
Article
Energy & Fuels
Talha Istkhar, Ainy Hafeez, Fahad Javed, Tahir Fazal, Faisal Ahmad, Arif Hussain, William B. J. Zimmerman, Fahad Rehman
Summary: The current study explores microbubble mediated reactive distillation to improve mass transfer, conversion, and reaction rate. Methyl acetate production was investigated as a case study, showing significantly higher conversion compared to previous studies. Response Surface Methodology (RSM) and Gated Recurrent Unit (GRU) models were used to analyze parameter correlations and predict responses, with GRU proving to be more robust and reliable than RSM.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2023)
Review
Chemistry, Physical
Pratik D. Desai, William B. Zimmerman
Summary: Microbubble dispersions are commonly used in industrial applications, and the wetting properties of microbubble generation devices have a significant influence on bubble size distribution. Recent studies have shown that wetting is an important factor in microbubble performance. It is recommended to assess the influence of wetting based on mechanisms/devices where wetting effects have been demonstrated.
CURRENT OPINION IN COLLOID & INTERFACE SCIENCE
(2023)
Article
Engineering, Chemical
Thomas D. Holmes, Bryony C. Moody, William B. J. Zimmerman
Summary: A plasma chemical reaction system can be accurately represented using a directed bipartite variable-relationship graph to analyze node influence and determine improved condition sequencing for a target outcome. A novel graph algorithm (OCARINA) was adapted for this graph and two conventional node-influence measures were also tested. The evaluation of the electron energy node influence using three different methods showed that OCARINA closely matched the simulation results for O-3 concentrations.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Engineering, Chemical
Fahed Javed, William B. Zimmerman, Tahir Fazal, Ainy Hafeez, Maria Mustafa, Naim Rashid, Fahad Rehman
Summary: A new heterogeneous catalyst, Bio-MOF complexed with an ionic liquid ([HMIM][HSO4]/Bio-MOF), has been synthesized and integrated with microbubble-mediated mass transfer technology to achieve a high conversion rate of biodiesel production. The catalyst demonstrates superior reactivity and stability.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2022)
Article
Biotechnology & Applied Microbiology
Fahed Javed, Muhammad Rizwan, Maryam Asif, Shahzad Ali, Rabya Aslam, Muhammad Sarfraz Akram, William B. Zimmerman, Fahad Rehman
Summary: This study focuses on the conversion of waste resources into biodiesel using a bifunctional catalyst and microbubble-mediated mass transfer technology. The results demonstrate a high conversion rate and stability using the 7% Sr/ZrO2 catalyst. Additionally, the one-step process reduces energy consumption, improves cost-efficiency, and simplifies the production process.
BIOENGINEERING-BASEL
(2022)
Article
Engineering, Chemical
Atheer M. G. Al-Yaqoobi, William B. Zimmerman
Summary: Controlling the size of bubbles is crucial for enhancing transport performance in gas-liquid systems. This study investigates the role of surface wettability on bubble size using the Washburn method. The results show that liquids with small contact angles produce smaller bubbles compared to liquids with higher contact angles. The study demonstrates the viability of the Washburn method in characterizing wettability and suggests that carefully choosing a diffuser material with better wettability can significantly reduce bubble size.
CHEMICAL AND PROCESS ENGINEERING-INZYNIERIA CHEMICZNA I PROCESOWA
(2022)
Correction
Chemistry, Applied
Jia Liu, Juntong Dong, Xiaodan Li, Teng Xu, Zhenguo Li, Jeffrey Dankwa Ampah, Mubasher Ikram, Shihai Zhang, Chao Jin, Zhenlong Geng, Tianyun Sun, Haifeng Liu
FUEL PROCESSING TECHNOLOGY
(2024)
Article
Chemistry, Applied
Seba Alareeqi, Daniel Bahamon, Kyriaki Polychronopoulou, Lourdes F. Vega
Summary: This study explores the potential application of single-atom-alloy (SAA) catalysts in bio-oils hydrodeoxygenation refining using density functional theory (DFT) and microkinetic modeling. It establishes the relationships between stability, adsorptive properties, and activity structures for bio-oil derivatives, providing guidance for the synthesis of cost-effective SAA combinations.
FUEL PROCESSING TECHNOLOGY
(2024)
Article
Chemistry, Applied
Bin Hu, Wen -Ming Zhang, Xue-Wen Guo, Ji Liu, Xiao Yang, Qiang Lu
Summary: This study explored the pyrolysis behaviors and mechanisms of different monosaccharides, including arabinose, galactose, galacturonic acid, and glucuronic acid. The roles of structural differences in these monosaccharides were analyzed, and it was found that glucuronic acid undergoes a special C-C bond breaking reaction during pyrolysis. The findings provide a deep understanding of the pyrolysis chemistry of hemicellulose and the role of different branches.
FUEL PROCESSING TECHNOLOGY
(2024)
Review
Chemistry, Applied
Youwei Zhi, Donghai Xu, Guanyu Jiang, Wanpeng Yang, Zhilin Chen, Peigao Duan, Jie Zhang
Summary: Hydrothermal carbonization (HTC) is an effective method for the harmless disposal of municipal sludge (MS) and offers potential applications for the obtained products. Optimizing reaction conditions, coupling with other waste materials, and combining different processes can improve the performance of HTC. Furthermore, HTC contributes to energy recovery and enhances the quality of life cycle assessment.
FUEL PROCESSING TECHNOLOGY
(2024)
Article
Chemistry, Applied
Jia Wang, Jianchun Jiang, Dongxian Li, Xianzhi Meng, Arthur J. Ragauskas
Summary: This study presents a scalable process for converting holocellulose and cellulosic wastes into advanced oxygen-containing biofuels with high furan, cyclic ketone, and ethanol content. By combining hydropyrolysis and vapor-phase hydrodeoxygenation using Pd/Al2O3 as a catalyst, the researchers achieved high yields and conversions. The integrated process holds great promise for biomass waste conversion into advanced biofuels.
FUEL PROCESSING TECHNOLOGY
(2024)
Article
Chemistry, Applied
Florian Held, Jannis Reusch, Steffen Salenbauch, Christian Hasse
Summary: The accurate prediction and assessment of soot emissions in internal combustion engines are crucial for the development of sustainable powertrains. This study presents a detailed quadrature-based method of moments (QMOM) soot model coupled with a state-of-the-art flow solver for the simulation of gasoline engines. The model accurately describes the entire cause-and-effect chain of soot formation, growth and oxidation. Experimental validation and engine cycle simulations are used to identify the root cause of observed soot formation hotspots.
FUEL PROCESSING TECHNOLOGY
(2024)
