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Flotation plays a relevant role in the concentration of iron ores. Conventional flotation technology employing mechanical machines and columns and also circuits combining both types of cells have been utilized in the iron ore industry. The top size of particles in the flotation circuit feed is 150 µm and the slimes below 10 µm are removed as overfl...
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A tremendous amount of research has been done on refining the flotation process for iron ore and designing the reagents which go into it. This paper reviews the industrial practices and fundamental research surrounding iron ore flotation. The advantages and disadvantages of direct flotation, cationic reverse flotation, and anionic reverse flotation...
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... They have been used for coal, industrial minerals (e.g., kaolin, feldspar, potash), and polymetallic ores (e.g., copper, molybdenum, gold, silver, and iron). Several case studies were reported for gold [9,11,21], copper [25,29], iron [30,31], and nickel and zinc [32,33]. There is a specific method defined by Maelgwyn Mineral Services Ltd. for the scale-up procedure based on practical test works using Imhoflot TM cells. ...
The present work investigates a comparative study between mechanical and Imhoflot TM cells on a mini-pilot scale and the applicability of one self-aspirated H-16 cell (hybrid Imhoflot TM cell) on an industrial scale on-site. The VM-04 cell (vertical feed to the separator vessel with 400 mm diameter) was fabricated, developed, and examined. The copper flotation experiments were conducted under similar volumetric conditions for both the Imhoflot TM and mechanical flotation cells keeping the rest of the parameters constant. Further, one H-16 cell was positioned at four different stages in the Gökirmak copper flotation circuit of the Acacia (Türkiye) copper beneficiation plant, i.e., at (i) pre-rougher flotation, (ii) rougher concentrate, (iii) cleaner-scavenger tailing, and (iv) first cleaning concentrate aiming at enhancing the flotation circuit capacity through flash flotation in the rougher stage, reducing copper grade in the final tailing, and increasing cleaning throughput, respectively. Comparative copper flotation tests showed that ultimate recoveries using the Imhoflot TM and mechanically agitated conventional cells were 94% and 74%, respectively. The industrial scale test results indicated that locating one pneumatic H-16 cell with the duty of pre-floating (also known as flash flotation) led to the enrichment ratio and recovery of 4.84 and 89%, respectively. Positioning the H-16 cell at the cleaner-scavenger tailings could diminish the copper tailings grade from 0.43% to 0.31%. Further, a relatively greater enrichment ratio and copper recovery were obtained using only one Imhoflot TM cell (1.76 and 64%) in comparison with employing four existing mechanical cells (50 m 3 , each cell) in series (1.45 and 60%) at the first cleaner stage.
... Polymineralization and the complexity of ores, along with the reduction in cut-off grades, have forced the mineral processing industries towards using fine and ultrafine grinding/re-regrinding stages to obtain adequate degrees of liberation [1]. Mechanical cells and columns have led to poor separation efficiencies in such particle size ranges, mainly associated with low collision efficiencies and particle surface oxidation [2][3][4][5]. Therefore, pneumatic flotation cells have been under continuous evaluation as alternative machines due to their favourable metallurgical responses in the fine fractions and their lower capital and operating costs. ...
... Therefore, pneumatic flotation cells have been under continuous evaluation as alternative machines due to their favourable metallurgical responses in the fine fractions and their lower capital and operating costs. Intensified flotation machines (also called reactor-separator cells) such as Imhoflot TM , Jameson TM , Concorde TM , Reflux TM , Allflot TM , and Pneuflot cells have proved their potential to replace a few mechanical cells and columns at similar or better metallurgical performances [4,[6][7][8]. The main advantages of these flotation cells are their capacity for an intense interaction between gas and particles, and their short flotation time that prevents particle surface oxidation. ...
This short communication presents residence time distribution (RTD) measurements and modeling in a 16 m 3 Siemens flotation cell, as the first RTD characterization in an industrial-scale pneumatic cell. The Siemens cell was installed as a pre-rougher machine in a Cu-Mo selective plant. This plant recovered molybdenite as an enriched product, depressing copper-bearing minerals. Irradiated non-floatable solid and Br 82 in water solution were employed as solid and liquid tracers, respectively. The tracers were instantly injected into the Siemens cell, and the inlet and outlet concentrations were directly measured by external non-invasive detectors. From the flotation literature, three model structures for the RTDs were evaluated, including perfect mixing, one large perfect mixer and one small perfect mixer in series (LSTS), and N perfectly mixed reactors in series. A transport delay was incorporated for all models. The LSTS representation was more consistent with the experimental data, showing that the Siemens cell RTDs presented significant deviations with respect to perfect mixing and plug-flow regimes. From the industrial measurements, mean residence times of 4.1-5.2 min were estimated.
... It is known that such pneumatic flotation cells a.k.a. intensified, or reactor-separator type cells possess effective hydrodynamic characteristics, no agitating/moving part, short retention time (Lima et al., 2018), and low capital and operating costs Safari et al., 2022). For instance, the operating and designing variable of the Jameson TM cell was reported in a series of articles (Cinar et al., 2007;Sahbaz et al., 2013;Ucar et al., 2014). ...
The present paper introduces the key advantages of ImhoflotTM, JamesonTM, and RefluxTM flotation cells over the conventionally used mechanical and column cells from different perspectives. The impact of slurry mean retention time, bubble size distribution, and energy input was studied for all cell types. The mean retention time of laboratory scale ImhoflotTM (V030-cell) and RefluxTM flotation cells (RFC100) were measured experimentally using KCl as a tracer. Also, initially a statistical and practical overview of previously installed ImhoflotTM, and JamesonTM cells was presented in this work. It was found that more industrial data is available for the JamesonTM cell. The diagnostic results showed that RefluxTM, JamesonTM, and ImhoflotTM functionally operate similarly based on providing intensive turbulence in the downcomer. They were initially applied to the Australian and the UK coal industries and installed in the cleaning stage of flotation circuits, while there are now more applications in a wide variety of minerals across the world in different flotation stages. First pilot trials on a Russian gold ore were reported operating both JamesonTM and ImhoflotTM cells at the rougher-scalper and cleaner stages providing superior results using the ImhoflotTM cell as rougher-scalper and the JamesonTM at the cleaner. Formation of sub-micron and micron-sized bubbles, effective hydrodynamic characteristics, and low capital and operating costs were reported as major advantages of intensified flotation cells over the conventionally used ones in improving the recoverability of ultra-fine particles. Literature data showed that these cells provide greater gas-hold-up values (40-60%) over the mechanical (5-20%) and column cells (5-25%) with substantially lower power inputs. It was indicated that low mean slurry retention time could lead to a potential enhancement in their throughputs, but further industrial measurements are required to prove this statement. The RefluxTM cell showed a plug-flow mixing regime, while ImhoflotTM V-Cell followed the trend of perfect mixing and plug-flow dispersion regimes.
... They showed that the pneumatic flotation cell had the best flotation performance under most operating conditions. Furthermore, Lima et al. (2018) addressed the same concept by comparatively analyzing mechanical and pneumatic devices for quartz flotation. ...
After more than a century applying flotation to the mining industry, two completely different strategies have been introduced for processing purposes. One is the classical approach viz. grinding ores to a certain extent (fine particles) and floating them via conventional mechanical and pneumatic cells i.e., Jameson, ImhoflotTM and RefluxTM. This strategy continues because mines face declining cut-off grades, complex and poly-mineralized ores, and they are required to achieve an acceptable degree of mineral liberation. The other school of thought deals with coarse particle processes mainly owing to the low energy requirements, that includes SkimAir® flash, fluidized bed and HydroFloatTM cells. There is no study in the literature to comparatively present the recent developments of flotation apparatuses versus the conventional mechanical cells. To cover this knowledge gap in the literature, the present paper endeavors to critically evaluate these concepts from several points of view, including existing technological advancements, water and energy usage, kinetics, and circuit design. A brief introduction of advanced technologies, along with their applications is presented. The data from literature and case studies showed that the Jameson, ImhoflotTM and recently developed RefluxTM flotation cells can be very effective for recovering fine particles owing to their specific hydrodynamic designs, intensive energy dissipation rate and generation of micron-sized bubbles (100-700 µm). Very low (less than a few minutes) mean particle residence time, high gas-hold up (ca. 50-70 %), no agitation and high efficiency of particle-bubble collision were identified as their main advantages compared to traditional mechanical flotation cells. In addition to their common applications in cleaner stage, these cells were used in pre-flotation and scalping (producing final concentrate from the rougher feed) duties. Their main challenges were recognized as relatively unclear procedure on their scale up/down, optimization and simulation. The HydroFloatTM cell was indicated as a promising technology for recovering coarse particle fraction sizes by taking advantage of the fluidized-bed concept with plug-flow dispersion regime, high particle residence time, and limited cell turbulence. We finally concluded that fine particle flotation may remain as the main focus of re-processing tailings dams, while coarse particle treatment should be the focus of this century to reduce total energy consumptions.
... They manifested that the pneumatic flotation cell shows the best flotation performance for most operating conditions. Lima et al. [50] addressed the same concept by comparatively analyzing mechanical and pneumatic cells for quartz flotation. Two commonly used pneumatic flotation machines are Jameson TM and Imhoflot TM cells discussed as follows. ...
... Pneumatic flotation cells are currently being considered for use on certain industrial iron ore operations, as promising results that have been observed in some industrial pilot trials in different sites at Vale Iron ore. Recent research indicated that they are more efficient for recovering coarse quartz particles than mechanical cells (Lima et al., 2018). The oscillating grid flotation cell (OGC) is a novel flotation column where one is able to introduce relatively uniform turbulence (Safari et al., 2014;Testa et al., 2017Safari et al., 2016aSafari et al., 2017). ...
This paper investigates the reverse flotation of iron ore in a laboratory mechanical, oscillating grid (OGC) and pneumatic flotation cell. The main objectives are to investigate the recovery of coarse quartz (+150 µm) by flotation and fine hematite (−25 µm) by entrainment. Agitation/energy input results show that coarse quartz recovery increases with increasing impeller speed to a maximum of ±70%. The recovery of coarse quartz in the OGC is ±10% higher than in the mechanical cell with an optimum at a low energy input of 0.1 W/kg. Froth height results show that coarse quartz recovery and fine hematite loss decrease by over 50% with increasing froth height. Solids concentration results show that coarse quartz recovery remains relatively constant with decreasing solids concentration, but fine hematite loss decreases from 15 to 5% at the maximum froth height due to lower water recoveries. The OGC generally results in the best overall flotation performance at lower energy input. The pneumatic flotation cell achieves better flotation performance than the mechanical flotation cell for most operating conditions.
... Pneumatic flotation cells are currently being considered for use on certain industrial iron ore operations, as promising results that have been observed in some industrial pilot trials in different sites at Vale Iron ore. Recent research indicated that they are more efficient for recovering coarse quartz particles than mechanical cells (Lima et al., 2018). The oscillating grid flotation cell (OGC) is a novel flotation column where one is able to introduce relatively uniform turbulence (Safari et al., 2014;Testa et al., 2017Safari et al., 2016aSafari et al., 2017). ...
This paper investigates the reverse flotation of hematite in three laboratory flotation cells with very different contacting environments. The main objectives are to investigate the recovery of coarse quartz by flotation and fine hematite by entrainment. The laboratory flotation cells used were the mechanical, oscillating grid and pneumatic cells. The effect of froth height and solid concentration were investigated in the mechanical and pneumatic cells.
The effect of impeller speed and energy input were investigated in the mechanical and oscillating grid cells. Froth height results show that coarse quartz particle recovery decreases almost linearly with increasing froth height due to increased detachment of coarse quartz particles in the froth. Fine hematite particle recovery also decreases almost linearly with increasing froth height due to decreased water recovery and associated entrainment. Agitation/energy input results show that coarse quartz particle recovery increases with increasing impeller speed to an optimum, after which this decreases dramatically. The increase is due to improved gas dispersion, generation of smaller bubbles and increased bubble-particle collision and attachment. The decrease is due to significantly increased bubble-particle detachment at higher impeller speeds. The recovery of coarse quartz particles in the OGC is higher than that in the mechanical cell with an optimum at a much lower energy input. Solids concentration results show that both mass recovery and water recovery increase with increasing solid concentrations. The pneumatic cell achieves higher mass recoveries and lower water recoveries than those in the mechanical cell at equivalent solids concentrations and operating conditions.
In this chapter, the most salient nanoscience and nanotechnology concepts related to extractive metallurgy, specifically mineral froth flotation, are discussed. The most relevant and current findings of nanotechnology‐based research in the domain of mineral processing and a concise overview of recent advances in the application of nanotechnology for improved mineral recovery using froth flotation technology is reported. In this ever‐expanding age of technologies to improve mineral processing, nanotechnology stands as one of the technologies which can revolutionize the mineral processing industry in general. Nanomaterials present novel properties, which can be exploited to generate exceptionally good reagents to improve recoveries and grades of minerals of interest during the froth flotation process. In light of these current developments, insight into potential future research directions for nanotechnology research in the domain of froth flotation of minerals is given.
