Fluidized Bed Research Articles

A Technical-Economic Assessment of Producing Hydrogen and Biofuels via Gasification of Biomass in Solar Hybridised Dual Fluidised Bed

In this work, the techno-economic performances of three conversion pathways using an upstream solar hybridised dual fluidised bed (SDFB) for biomass gasification were assessed. The annual solar share % over the solar multiple range of 1.4-3.4 varies between 7-17%, with the CO2 emissions avoided relative to the non-solar case varying between 7%-23%, using representative solar viability location in Australia. The projected break-even price varies between 5.5-6.1 AUD/kg (3.8-4.25 USD/kg) for hydrogen, 1.1-1.2 AUD/kg (0.75-0.85 USD/kg) for methanol, and 1.5-1.7 AUD/L (1.1-1.2 USD/L) for liquid fuels over the analysed oversize level of 1.4 to 3.4 at thermal storage capacity designs with less than 1% solar dumping rate for base case scenario. Overall, the derived break-even price from the SDFB gasifier configuration is higher than that of the non-solar gasifier case, yet this is dependent on the cost of supplement heat supply and carbon credit

Continuous Chiral Inversion by Coupling Enzymatic Racemization with Enantioselective Fluidized Bed Crystallization

Continuous Chiral Inversion by Coupling Enzymatic Racemization with Enantioselective Fluidized Bed Crystallization

Desulfurization of pyrolytic oils from waste tire pyrolysis in a fluidized bed reactor with boron nitride adsorbents

The study focused on producing hexagonal boron nitride (hBN) as an adsorbent which provides high efficiency in desulfurization processes. The synthesized hBN is used for sulfur removal from liquid fuel derived from end-of-life tires (ELTs). Characterization of hBN was performed using FTIR, XRD, TGA, and SEM-EDS analyses. Liquid fuel was produced in a fluidized bed reactor at 550 °C under a nitrogen gas flow. Post-desulfurization, the fuel's density, water content, and calorific value increased, while sulfur content and flash point decreased, with sulfur content showing a significant reduction of 79.23 %. The desulfurized fuel (PS-A) exhibited better combustion characteristics and closely resembled diesel fuel performance, though it slightly reduced engine effective efficiency by 1.06 % compared to diesel. Both PS-A and pre-desulfurized fuel (PS-B) significantly reduced soot emissions by 23.28 % and 20.81 %, respectively, compared to diesel. Additionally, CO emissions were lower for PS-A and PS-B, with reductions of 4.35 % and 2.00 %, respectively. However, CO2 emissions increased by 1.60 % for PS-A and 0.86 % for PS-B, attributed to higher fuel consumption. Overall, hBN effectively reduced sulfur content and improved several fuel properties of pyrolytic liquids. The study highlights the environmental and economic benefits of enhancing ELT-derived liquid fuels and suggests potential applications in real systems, serving as a foundation for new technologies and projects.

Managing Heat Transfer Intensity in a Fluidized Particle-in-Tube Solar Receiver

Particle flow structure and associated heat transfer coefficient are examined as a function of temperature in a single-tube fluidized bed solar receiver operating in upward particle flow mode. It is found that temperature has a strong effect on both fluidization regimes and wall-to-bed heat transfer coefficient that varies in the range 800-1200 W/(m2.K). Turbulent fluidization regime results in the most intense heat transfer between the irradiated wall and the fluidized particle.

Novel Fimasartan Fluidized Solid Dispersion and Its Tablet: Preparation, Crystallinity, Solubility, Dissolution, and Pharmacokinetics in Beagle Dogs.

Fimasartan, an angiotensin II receptor antagonist, exhibits low bioavailability due to its poor solubility; consequently, using solubilization technologies is essential to improve its bioavailability. In this study, novel fimasartan fluidized solid dispersion (FFSD) was developed using a fluid bed granulator to enhance the drug solubility andoral bioavailability. An appropriate FFSD was prepared in 50% ethanol using a fluid bed granulator, and its drug dissolution, morphology, and crystallinity were evaluated in comparison to the powdered drug. Moreover, the dissolution in various pH conditions and pharmacokinetics of the FFSD tablet in beagle dogs were investigated compared to the commercial fimasartan tablet. Among the hydrophilic polymers tested, hydroxypropyl methylcellulose (HPMC)showed the highest solubility. The FFSD, composed of fimasartan, HPMC, and microcrystalline cellulose at the weight ratio of 20:10:25, gave a granular aggregation of several particles with a smooth surface. The drug in this FFSD existed as an amorphous state, leading to a greatly increased drug dissolution. The FFSD tablet was prepared by compressing a mixture of FFSD, mannitol, croscarmellose sodium, and magnesium stearate at the weight ratio of 55:40:5:1. The FFSD tablet gave significantly higher drug dissolution, plasma concentrations, maximum plasma concentration (Cmax) andarea under the whole blood concentration-time curve (AUC) values than did the commercial fimasartan tablet. In the beagle dogs, the FFSD tablet (140.39±27.40ng·h/ml) had about a 1.7-fold higher AUC than the commercial fimasartan tablet (80.58±22.18 ng·h/ml), indicating an enhancement in thebioavailability. This novel FFSD tablet could be a potential oral pharmaceutical product with the improved oral bioavailability of fimasartan.

Pharmaceuticals removal from hospital wastewater by fluidized aerobic bioreactor in combination with tubesettler

Micropollutants, especially pharmaceutical compounds, are of significant concern owing to their ngL− 1 to µgL− 1 concentration, making them difficult for conventional treatment plants to remove from wastewater. Despite municipal wastewater treatment plant being a primary source of these compounds to be released into the wastewater, on comparison little attention has been given to hospital wastewater. The major focus of studies addressing pharmaceutical compounds is based on synthetic wastewater. This study addresses this research gap by treating wastewater to remove micropollutants (Fluvastatin, ketoprofen, paracetamol, ciprofloxacin, carbamazepine, sulfamethoxazole, and lorazepam) by employing a fluidized aerobic bioreactor. Tubesettler was attached to a fluidized-bed bioreactor to see if it could be used as a polishing unit rather than a secondary clarifier. The environmental risk from the effluent discharge into the environment was assessed regarding the hazard quotient. The paracetamol and ketoprofen were removed at an efficiency of 51% and 60%, respectively, followed by carbamazepine at 50%, ciprofloxacin at 40%, fluvastatin at 47%, sulfamethoxazole at 31%, and lorazepam at 20%. The influent posed moderate environmental risk with (Hazard Quotient) HQ > 0.5, while in effluent the risk was reduced with HQ value 0.4. For effluent from fluidized bed bioreactors (HQ 0.13) and tube setters (HQ 0.15). The associated tube settler was found suitable for polishing units with additional removal efficiencies of 15–43% for all the targeted pharmaceutical compounds. Further studies are required to explore disinfectants’ effect on the reactor’s biodegradation efficiency. Also, further modification and a hybrid version of the fluidized bed bioreactor can be used.

Experimental quantification of interparticle forces in gas-solid fluidized beds operating at temperatures from ambient to 1500 °C

The successful design and operation of high-temperature gas-solid fluidized bed reactors require a deep understanding of interparticle forces (IPFs). However, experimentally quantifying IPFs at elevated temperatures has been a significant challenge due to the lack of suitable methods. This study addresses this gap by introducing a simple yet reliable experimental approach to quantify IPFs in a gas-solid fluidized bed across a temperature range from ambient to 1500 °C. The experimental results reveal that IPFs increase gradually with temperatures up to 1200 °C and become more pronounced at higher temperatures. Smaller particles, or those prone to changes in morphological, structural, and chemical properties—such as softening, sintering, or the formation of low-melting-point eutectic compounds at high temperatures—intensify IPFs significantly. This phenomenon is corroborated by our experiments and comparison with literature data across various temperatures and particle types. Finally, two empirical correlations are proposed to predict IPFs as temperature and particle diameter functions for coarse particles in high-temperature fluidized beds. These findings enhance the understanding of IPFs in high-temperature fluidized beds and are valuable for developing such systems for industrial applications.

Investigating combustion efficiency and NOx emission reduction in fluidized bed ammonia-coal co-firing

Ammonia, a carbon-free fuel, can significantly reduce CO2 emissions when co-fired with coal in power plants. Fluidized bed combustion, known for its excellent gas-solid mixing and low NOx emissions, is a promising method for ammonia-coal co-firing. However, challenges remain in optimizing ammonia injection and controlling nitrogen oxide emissions. This study investigates these aspects using a lab-scale fluidized bed reactor with flexible ammonia injection points. Key variables, such as ammonia co-firing ratios, injection location, temperature, and outlet oxygen concentration, are examined. The results show that with ammonia injection ratios up to 70 %, NO and N2O emissions slightly increase, while ammonia escape is maintained below 5 ppm. Air staging effectively controls NOx emissions, and higher temperatures promote N2O decomposition, but increase NOx levels. Ammonia injection does not raise unburned carbon content. Rate of production and sensitivity analyses highlight the role of OH radicals in ammonia conversion and identify the critical reactions affecting NO generation. This study highlights the feasibility of fluidized bed ammonia-coal co-firing technology.

Insights into the environmental risk variation of heavy metals from MSWI fly ash after thermal plasma vitrification

Thermal plasma vitrification of municipal solid waste incineration fly ash (MSWI FA) shows potential for effective dioxin degradation and heavy metal immobilization. However, the environmental risks posed by heavy metals released after vitrification remain understudied. This work investigates two types of MSWI FA—circulated fluidized bed fly ash (CFA) and mechanical grate furnace fly ash (GFA)—blended with waste glass and vitrified via thermal plasma treatment. The physical and chemical properties of the original FA and vitrified glasses (CFA-glass and GFA-glass) were analyzed. Environmental risks were assessed using the risk assessment code (RAC) and the overall pollution toxicity index (OPTI). Results showed that CFA, with higher Si and Al content, exhibited better vitrification than GFA. Plasma vitrification reduced chlorine content from 5.79 % and 10.59 % to 0.22 % and 0.16% due to Cl volatilization. Heavy metals with low boiling points, such as Cd and Pb, were significantly reduced, while high-boiling-point Cr, Ni remained and the acid resistance of vitrificated FA significantly deteriorated, which increased the potential leaching of heavy metals. In alkaline conditions, the OPTI value of CFA-glass dropped to 2, indicating a strong immobilization effect. This study provides critical insights for managing heavy metals in fly ash through thermal plasma vitrification.

Influence of Polymer Film Thickness on Drug Release from Fluidized Bed Coated Pellets and Intended Process and Product Control.

Coated drug pellets enjoy widespread use in hard gelatine capsules. In heterogeneous pellets, the drug substance is layered onto core pellets. Coatings are often applied to generate a retarded release or an enteric coating. In the present study, the thickness of a polymer coating layer on drug pellets was correlated to the drug release kinetics. The question should be answered whether it is possible to stop the coating process when a layer thickness referring to an intended drug release is achieved. Inert pellets were first coated with sodium benzoate and second with different amounts of water insoluble polyacrylate in a fluidized bed apparatus equipped with a Wurster inlet. The whole process was controlled in-line and at-line with process analytical technology by the measurement of the particle size and the layer thickness. The in-vitro sodium benzoate release was investigated, and the data were linearized by different standard models and compared with the polyacrylate layer thickness. With increasing polyacrylate layer thickness the release rate diminishes. The superposition of several processes influencing the release results in release profiles corresponding approximately to first order kinetics. The coating layer thickness corresponds to a determined drug release profile. The manufacturing of coated drug pellets with intended drug release is possible by coating process control and layer thickness measurement. Preliminary investigations are necessary for different formulations.

Literature Review on Thermodynamic and Kinetic Limitations of Thermal Decomposition of Methane

The state of the art in methane pyrolysis does not yet provide a definitive answer as to whether the concept of an elementary reaction is universally applicable to the apparently simple process of methane dissociation. Similarly, the literature currently lacks a comprehensive and unambiguous description of the methane pyrolysis process and, in particular, a single model that would well represent its course at both the micro and macro scales. Given the wide range of conditions under which this reaction can occur—whether thermal or thermo-catalytic, in solid or fluidized bed reactors—it is crucial to evaluate the usefulness of different kinetic models and their compatibility with basic thermodynamic principles and design assumptions. To address these research gaps, the authors analysed the thermodynamic and kinetic dependencies involved in the thermal decomposition of methane, using the synthesis of methane from its elemental components and its reversibility as a basis for exploring suitable kinetic models. Using experimental data available in the literature, a wide range of kinetic models have been analysed to determine how they all relate to the reaction rate constant. It was found that regardless of whether the process is catalytic or purely thermal, for temperatures above 900 °C the reversibility of the reaction has a negligible effect on the hydrogen yield. This work shows how the determined kinetic parameters are consistent with the Kinetic Compensation Effect (KCE) and, by incorporating elements of Transition State Theory (TST), the possibility of the existence of Entropy–Enthalpy Compensation (EEC). The indicated correspondence between KCE and EEC is strengthened by the calculated average activation entropy at isokinetic temperature (∆SB=−275.0 J·(mol·K)−1). Based on these results, the authors also show that changes in the activation energy (E=20–421 kJ·mol−1) can only serve as an estimate of the optimal process conditions, since the isoconversion temperature (Tiso=1200−1450 K>Teq) is shown to depend not only on thermodynamic principles but also on the way the reaction is carried out, with temperature (T) and pressure (P) locally compensating each other.

Bubble characteristics in a novel microbubble gas-liquid-solid fluidized bed

The bubble characteristics are critical in gas-liquid-solid fluidized beds and microbubbles significantly enhance mass transfer in multiphase systems. In this work, a novel concept of microbubble gas-liquid-solid fluidized bed is proposed. Telecentric camera is employed to measure and analyze the microbubble characteristics including bubble size and gas holdup in this three-phase fluidized bed. Additionally, solid holdups in the fluidized bed are also examined. The results demonstrate that the bubble size adheres a lognormal distribution and is significantly influenced by superficial gas velocity. Bubble diameter exhibit a relatively uniform distribution in the radial direction. Bubbles exceeding than 1 mm substantially affect local gas holdup, and the microbubble flow promotes a more uniform distribution of local gas holdup in radial position. The average gas holdup deviation is less than 15 % compared to overall gas holdup obtained from pressure drop. Although microbubbles are more abundant, larger bubbles (> 1 mm) contribute more to solid particle fluidization. This paper introduces a methodology for assessing smaller-sized microbubbles in three-phase flow. The hydrodynamic analysis of the microbubble gas-liquid-solid fluidized bed establishes a foundational framework for enhancing gas-liquid mass transfer in fluidized bed.

Data-driven insights into the properties of liquisolid systems based on machine learning algorithms

Liquisolid systems (LS) represent a formulation approach where liquid drug or its dispersion is transformed into a powder with good flowability and compactibility, leading to enhanced drug dissolution and bioavailability. Many research groups have focused on the preparation and investigation of LS, leading to a higher need for comprehensive evaluation of factors impacting LS characteristics. The aim of this work was to investigate the applicability of machine learning algorithms in the LS evaluation, using data mined from published literature, and provide an insight into critical factors governing the liquisolid system performance.The dataset was prepared using publication search engines and relevant keywords, with a total of 425 formulations included in the database. The database focused on preparation methods, formulation parameters, and liquisolid system characteristics. Subsequently, critical properties of the liquisolid system, i.e. flowability, compact hardness, and drug dissolution, were analyzed using machine learning algorithms, including Gradient Boosting, Adaptive Boosting and Random Forest.In addition to conventional preparation methods and excipients, novel technologies (fluid bed preparation, extrusion/spheronization) and materials (Neusilin®, Fujicalin®, and Syloid®) enhanced the properties of liquisolid systems. The analysis revealed that formulation factors, such as carrier and coating agent type and content, liquid phase load, model drug type and content, as well as preparation method, significantly influenced liquisolid system characteristics. The models developed exhibited high prediction accuracy when applied on test data (higher than 80 %). This indicates that the machine learning models may provide an insight into the critical attributes affecting the LS performance and may be used as a valuable tool in the development and optimization of these samples.

Pathways and enhancement strategies for magnesium hardness removal in modified induced crystallization softening

Elevated levels of total hardness in drinking water can readily result in scaling, which poses a threat to both the safety of water quality and the convenience of its use. While there is a wealth of research on the removal of calcium hardness, there is a dearth of studies focusing on the removal of magnesium hardness. In light of this, the present study employs modified induced crystallization softening (MICS) to delineate the removal pathways and mechanisms of magnesium hardness, and to investigate viable methods for its enhancement and application. Our research has determined that magnesium hardness can be effectively removed from water through the MICS, with the dosage of softening agents (NaOH) being a significant factor that influences this removal, whereas the fixed bed height within the fluidized bed exerts minimal impact on the process. In the low-dose stage (less than 250 mg/L), when the pH is below 10.0, up to 20% of magnesium hardness can be removed, predominantly through the crystallization of (Ca0.936Mg0.064)CO3. As the dosage increases to the moderate stage (250–400 mg/L), the conversion of excess bicarbonate (HCO3−) to carbonate (CO32−) in the water hinders further removal of magnesium hardness. In the high-dose stage (exceeding 400 mg/L), when the pH rises above 10.5, the removal rate of magnesium hardness can be enhanced to over 75%, with the crystallization of Mg(OH)2 being the primary removal mechanism. Density functional theory calculations, along with molecular dynamics simulations of cohesive energy and bond energy, substantiate the feasibility of the identified magnesium removal pathways. The addition of coagulants (FeCl3) and an decrease in the up-flow velocity can further augment the removal efficiency of magnesium hardness by promoting the crystallinity of Mg(OH)2 during the high-dose stage (exceeding 400 mg/L). In practical engineering applications, the strategic control of softening agent dosages enables the achievement of varying levels of magnesium hardness removal, tailored to specific water quality requirements.

A multicommuted flow system with a solid–liquid extraction chamber to extract and quantify total phenolic compounds from solid samples

Multicommutation significantly enhances the versatility of flow systems by integrating solenoid micro-pumps or valves. In this novel approach, the flow system was fitted with four solenoid micro-pumps to enhance mixing conditions, minimize reagent use and waste production, and quantify total phenolic compounds (TPC) via the Folin-Ciocalteu method. The extraction module was constructed with a 1000 µL pipette tip, a frit, and cotton used as a filter. The fluidized bed column was continuously agitated with a vibratory shaker, the extraction solution (ethanol 5 % (v/v)), and the solid samples (50 mg). The extraction of TPC was started by pumping the extraction solution through P1 (150 pulses). The analytical cycle was established by delivering the extraction solution and reagents through P1 (4 pulses), P3 (Folin-Ciocalteu 20 % (v/v); 1 pulse), and P4 (sodium carbonate 2 % (w/v); 1 pulse). These aliquots were rapidly mixed at the interfaces, initiating the first sampling cycle. This process was repeated seven times to create the sample zone and was directed towards detection at 740 nm by activating P2. Under optimized experimental conditions, a linear response was observed from 1 to 20 mg L-1 gallic acid, as described by the equation Absorbance = 0.023 + 0.028C (mg L-1), r = 0.997. At a 99.7 % confidence level, the detection limit, coefficient of variation (n = 11; 10 mg L-1), and sampling rate were determined to be 188 µg L-1, 0.1 %, and 100 determinations per hour, respectively. The consumption of reagents for each determination was estimated at 0.95 mg of sodium carbonate and 9.5 µL of Folin-Ciocalteu, resulting in 3.4 mL of waste generated. Phenolic compounds were quantified between 694 and 1760 mg in 100 g−1 food flour dry samples. Results obtained by the proposed process agreed with those obtained with batch extractions (95 % confidence level). Typical characteristics of systems that use solenoid micro-pumps are portability, cost-effectiveness, low energy consumption, improved mixing, and reproducibility in handling micro-volume solutions. The proposed procedure demonstrates its versatility and effectiveness by offering a practical alternative for extracting and quantifying total phenolic compounds in various solid matrices. This approach proves to be a superior option compared to existing methodologies.

Vertical baffles in a fluidized bed reactor: Hydraulic assessment with a numerical and experimental approach

The hydrodynamics of a mini fluidizedbedreactor with and without vertical baffles has been studied with Computational Fluid Dynamics (CFD) and verified experimentally for several selected configurations. The CFD – Lagrangian Multiphase Method (CFD-LMM) approach was adopted. The gas was fed at a flow rate of 18Lmin−1 via twelve tangential inlets, creating a vortex flow around a cone in the downstream section, and additionally via a single vertical inlet (2Lmin−1) in the top plane of the cone. Relevant parameters on the friction factor, namely baffle height, inclination angle, arrangement of the baffles and the distance between the two baffle sets, have been studied. The results showed that increasing the number of baffles, the particle non-uniformity parameter decreases from 75 to 40 %. Moreover, the aligned arrangement was superior to staggered one by providing more fluid mixing. Finally, the trapezoidal baffles further improved the bed uniformity, allowing a decrease of the experimental particle non-uniformity index by more than four times as compared to the reactor without baffles tested in the same conditions.

Analysis of difficult flotation mechanisms for coarse low-rank coal: Comparing fluidized-bed and mechanical flotation technologies

Efficient flotation of coarse low-rank coal is essential for enhancing energy utilization in the mineral processing industry. As the beneficiation equipment scales up, the precision of particle size classification before flotation decreases, leading to a higher coarse particle content in the feed, which poses significant challenges to traditional flotation processes. Recent advancements in fluidized bed flotation technology have demonstrated considerable advantages in the flotation of coarse-grained metallic minerals; however, its application to coarse low-rank coal remains relatively unexplored. This study investigates the potential of fluidized bed flotation technology for coarse low-rank coal, employing various analytical methods to elucidate difficult flotation mechanisms. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were utilized to comprehensively characterize the surface morphology and chemical composition of coal samples. The influence of increasing particle size on flotation performance was systematically assessed through measurements of induction time and critical detachment amplitude. Comparative flotation experiments were conducted to evaluate the efficacy of traditional mechanical flotation against fluidized bed flotation technologies. Results indicate that the presence of cracks and oxygen-containing functional groups on the coal surface significantly enhances hydrophilicity, hindering flotation recovery rates. With increasing particle size, the induction time between particles and bubbles lengthens, while the critical detachment amplitude decreases, weakening the attachment and increasing detachment likelihood. Although high-efficiency collectors enhance coal particle hydrophobicity, they cannot fully mitigate the turbulence disrupting bubble-particle interactions in mechanical flotation. Conversely, fluidized bed flotation effectively minimizes turbulence interference, leading to an approximate 40 % increase in the recovery rate of coarse low-rank coal (0.25–1.00 mm) compared to traditional mechanical flotation. This study presents a novel technological approach for the efficient recovery of coarse low-rank coal, contributing to the clean utilization of low-rank coal resources.

Insight into particle size distribution and particle-scale reactions in a supercritical water fluidized bed reactor by CPFD method

Supercritical water gasification (SCWG) provides a promising solution for converting coal into hydrogen-rich gaseous. However, the modelling of the coal SCWG process still poses challenges due to the heterogeneous particle distribution, large quantity of particles, and complex chemical reactions. This study presents a novel three-dimensional numerical model based on computational particle fluid dynamics (CPFD) to study coal particle gasification in the reactor. The model integrates realistic coal particle size distribution, heat and mass transfer phenomena alongside heterogeneous/homogeneous chemical reactions across phases, elucidating multi-scale reacting flow behaviors and illustrating particle volume fraction, size, and velocity distributions. The obtained results reveal the evolution of coal composition, particle scale gasification process, and distribution of gaseous product components in the supercritical fluidized bed reactor. This work aims to serve as a reference for understanding the flow and heat transfer phenomena between supercritical water and coal particles in SCWG reactors.

Numerical simulation of fluidized bed reactor for calcium looping energy release process in thermochemical storage: Influence of key conditions

The thermochemical energy storage technology applied to concentrating solar power is expected to realize the large-scale deployment of solar power. Reactor design is recognized as a key challenge. In this study, the calcium looping energy release process in a bubbling fluidized bed reactor was numerically simulated using an Eulerian-Eulerian Two-fluid Model. The effects of immersed tubes, particle size, CO2 concentration, and flow velocity on the multi-physical coupling characteristics during the carbonation process were explored. The result indicated that the presence of immersed tubes improves flow characteristics and effectively controls the bed temperature. Particle size had no significant effect on the carbonation process during the kinetically controlled stage. Increasing CO2 concentration significantly enhanced the conversion rate; however, it could lead to a reduction in particle renewal frequency, thereby deteriorating the heat transfer coefficient (HTC). The study on flow velocity indicated that a balance should be struck between bed stability and reaction conversion rate, with the model identifying 0.48 m/s to 0.74 m/s as the suitable operating gas velocity. Additionally, the study compared two methods for calculating HTC and analyzed the energy utilization efficiency during the carbonation process, providing recommendations for industrial applications.

Innovative fluidized bed flotation column for fine particle separation

Flotation columns are extensively utilized to separate fine mineral particles. In highly turbulent environments, the increased collision efficiency between bubbles and particles can lead to improved flotation efficiency of fine particles. The fluidized bed flotation column (FBFC), a new type of flotation equipment, improves the separation efficiency of fine particles by creating a highly turbulent environment in the fluidized zone through the addition of solid particles. This paper investigated the fluidization characteristics, bubble, and gas hold up of the FBFC, along with the flotation efficiency of fine quartz particles. Experimental results showed that introducing gas enhanced the fluidization process in the fluidized bed. The fluidized zone facilitated the fragmentation of bubbles into smaller ones. With increasing liquid velocity, the bubble diameter decreases before subsequently increasing, while the gas holdup initially rises and then declines. The flotation efficiency of fine quartz particles is superior in FBFC with added particles compared to those without added particles. The flotation efficiency of fine particles increases with the rise in both liquid velocity and gas velocity.