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Adsorption of anionic collector onto a solid surface. The anionic portion is responsible for the attachment of the collector molecule to the surface, while the hydrophobic part alters the surface hydrophobicity.
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... collectors are weak acids or acid salts that ionize in water, producing a collector that has a negatively-charged end that will attach to the mineral surfaces, and a hydrocarbon chain that extends out into the liquid, as shown in Figure 7. ...
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... Froth flotation is a method for physical separation of particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in mineral/water slurry [10]. It is a process of separating and concentrating minerals based on differences in the physicochemical properties of interfaces in view. ...
... The air inlet was then turned on fully and scheming of the froth was continued for 3 minutes. The procedure was repeated at varying pH of 5, 7, 9 and 10 [10]. After froth flotation, each product of froth flotation recovered (froth and depressed) were allowed to settle for 24 hours before decanting, filtered, dried at a temperature of 105 °C and weighed. ...
This study investigates the characterization of Fanibi Laterite and the efficiency of froth flotation to beneficiate nickel from its host rock sourced in Akure, Ondo State, Nigeria. A sample of the laterite was obtained and characterized by the use of an X-ray fluorescence Spectrometer (XRFS), X-ray diffractometer (XRD), and Scanning electron microscope with Energy dispersive spectroscope (SEM/EDS). The ore was comminuted to its liberation size of -125 + 90 µm. The froth flotation process was done using Sodium hydroxide and Hydrogen tetraoxosulphate (VI) acid as hydrogen potential (pH) modifier within the range of 4,5,7,9 and 10. However, other reagents are sodium oleate as the collector, potassium dichromate as the depressant, and oleic acid as the frother. The froth and depressed obtained were dewatered and characterized using XRFS. The result revealed that the ore contained 35.65% Si, 8.24% Al, 10.87% Fe, and 0.07% Nickel. It also included some other associated minerals such as Zn, Mg, Ti, Co, and Mo in trace form of less than 1 %. XRD analysis reveals nickel as nickel iodate. The result reveals nickel assays of 0.14, 0.20, 0.15, 0.25, and 0.12%, while their recoveries are 70.82, 67.80, 86.70, 98.04, and 86.98%, respectively. The optimum nickel recovery of 98.04% was attained at a pH of nine (9). It was concluded that froth flotation could successfully beneficiate Fanibi laterite ore for nickel. At the same time, other minerals such as Titanium, Molybdenum, Tin, and Tungsten were present to be extracted for Metallurgical applications.
... The results support the increased recoveries affecting the grade of the minerals recovered. The high grade recovered is attained by the collector's ability to be adsorbed onto the desired mineral, they essentially form a layer of nonpolar hydrophobic hydrocarbons which are bubbled out during flotation (Mpongo & Siame, 2006;Langa et al., 2014;Kawatra, 2011). This means that the bubbles in the froth are too large and sweep the particles past without coming into contact. ...
For several years, mining waste has shown a negative impact on both the environment and human health. The mining industry remains the backbone of the economic growth. Different technologies have been implemented to beneficiate and recover platinum group metals from tailings. The recycling of tailings has been a point of research interest due to their extensive applications. Flotation has been the primary process of upgrading and recovering PGMs. The focus of this study was to optimize flotation conditions in the beneficiation of PGMs for particular small-scale mine tailings. This was done to obtain the most favourable conditions for the small-scale mine tailings to improve operating conditions of specific particle sizes. PGMs tailings obtained from a small-scale mine were characterized using XRD, XRF, SEM/EDS, and ICP – OES to understand the properties of the tailings prior to mineral processing. Flotation batch tests were conducted. The results showed that the chosen particle size was 75 µm, and the favorable reagent dosages were 150 g/Mg and 100 g/Mg for SIBX (collector) and Starch(depressant), respectively. At favourable conditions, the recovery was 65.75% (Pt = 70.38%, Pd = 59.33%, Ru = 34.56%), and the grade was 31.46 g/Mg (Pt = 21.43 g/Mg, Pd = 9.62 g/Mg, Ru = 0.41 g/Mg). It can be concluded that all the flotation parameters are related; lower particle sizes yield high recoveries and better grades due to the exposure of the particle surface to the reagents responsible for the flotation of the PGMs. It was observed that the high collector dosages produce high recoveries with low grades of PGMs. High depressant dosages produce low recoveries with high grades of PGMs. The relationship between the collector and the depressant is of essential importance in the flotation process.
... Column and Jameson cells have froth-washing systems to ensure that the entire froth surface is washed, while mechanical cells utilise washing at the cell lip [32]. Froth washing is also widely used in cleaner stages of flotation cells [29,83,84]. However, little application has been reported in scavenger cells, which contain the largest amounts of gangue particles compared to floatable material [32]. ...
In the attempt to process lower-grade ores, mineral flotation has taken centre stage as the preferred recovery route. However, in many instances, the froth product does not have a high grade due to the entrainment of gangue minerals. Industry has solved this challenge by introducing froth washing mechanisms. Clean wash water is introduced into or on top of the froth to reduce the amount of entrained gangue in the final concentrate. This article reviews froth-washing systems in detail and highlights the advantages and disadvantages of each wash-water delivery mechanism. Comments on industrial uptake are provided. The indications are that froth washing improves the grade of the concentrate and influences froth stability and mobility. Other researchers have reported an improvement in recovery—especially of coarse particles—with wash water being added, while others have reported a reduction in recovery, especially with composite particles. Froth washing is generally applied in mechanical flotation cells by washing at the lip. In column flotation cells and Jameson cells, wash water is added to the entire froth surface. The literature also indicates that the wash-water rate, wash-water quality, type of wash-water delivery/ distribution mechanism and the area covered by wash water are critical parameters that dictate the efficacy of the washing system. Further research is necessary on the impact of wash-water quality on the froth phase sub-processes including froth rheology.
... In froth flotation, particles are separated based on the ability of air bubbles to selectively adhere to the surfaces of specific minerals. The hydrophobic particles attached to air bubble can in fact rise to the surface of the slurry and be separated from the hydrophilic ones that remain in the bulk of the liquid phase [19]. This requires the aid of additives such as collectors, frothing agents, and modifiers to enhance or suppress the wettability, thus enhancing the separation. ...
This white paper covers the fundamentals of hydrometallurgical process synthesis, design, and economic evaluation. Metallurgical and Materials Engineering students and engineers with limited process design experience find it particularly useful. It features theory on process synthesis and analysis, material on hydrometallurgical process simulation, and presents a thorough methodology for estimation of capital and operating costs. It also includes the following five detailed process examples modeled and analyzed with SuperPro Designer: 1) Extraction of Lithium from Spodumene Ore, 2) Bio-Hydrometallurgical Recovery of Copper and Gold, 3) Recycling of Solar Photovoltaic Panels, 4) Hydrometallurgical Recycling of Lithium-Ion Batteries and 5) Manufacturing of NMC 811 Cathode Material for Lithium-Ion Batteries. For additional hydrometallurgical examples of SuperPro Designer, please visit https://www.intelligen.com/industries/metallurgy/
... In the reverse cationic flotation of iron ore, silica is rendered hydrophobic by the amine analyzing grade and recovery curves the point located higher up and farther to the right would indicate the best performance (Kawatra, 2009). In this case 45 ppm of calcium yielded the best performance with a grade of 58.9 +/-0.3wt% ...
The reverse cationic flotation of hematite is the most common method to process hematite ores. The goal of this research is to understand the impact of fundamental water and surface effects to enable the optimization of the flotation process. At present, reverse cationic flotation is performed using a single chemical as both collector and frother. Excessive amounts of frother or collector should lead to diminished performance. This research investigates this phenomenon by replacing some of the collector with frothers. It was found that flotation recovery can be improved up to 2.5wt% via 10% replacement with methyl isobutyl carbinol (MIBC). Since most frothers are less expensive than the amine collector, there is a possibility of reducing cost of reagents and increasing profits in industry. There is a large body of literature on the impact of calcium on the flotation process. However, despite magnesium and calcium often being treated as interchangeable in literature and practice, magnesium’s smaller atomic size suggests that its behavior in flotation should be stronger. This research investigates the effect of calcium and magnesium in the adsorption of starch onto the hematite. We have found that initially both ions are beneficial to the process but as the magnesium concentrations increase, it becomes detrimental to flotation. These results make it clear that magnesium is not a one-for-one replacement of calcium in iron ore flotation, and should be accounted for and, if necessary, controlled separately. Lastly, the time it takes for the hematite to become fully hydrated may play a role in flotation. If the hydration of fresh surfaces takes place during the ½ to 2 hours that the xix hematite is expected to reside in the concentration process, then this could have a significant impact in flotation. In this research, the time scale of the hydration of pure hematite was determined to be on the order of 5 to 20 minutes, which tells us that in a plant-scale operation, it is very likely that the hematite is completely hydrated before it reaches flotation. These findings demonstrate improved understanding of reverse cationic flotation, which leads to a set of clear process recommendations.
... Figure 7 shows the grade and recovery plot at various concentrations of calcium to determine the optimum calcium concentration for this flotation setup. Typically, when analyzing grade and recovery curves the point located higher up and farther to the right would indicate the best performance (Kawatra 2009). In this case 45 ppm of calcium yielded the best performance with a grade of 58.9 ± 0.3 wt% Fe and an iron recovery of 62.8 ± 0.5 wt%. ...
Although extensive research has been conducted on the effect of water chemistry in flotation, no single study exists which describes the effect of calcium and magnesium on the adsorption of starch onto the hematite in iron ore flotation. In this work flotation, entrainment, zeta potential, and settling tests were performed to determine the differing impact of calcium and magnesium in iron ore flotation. Results showed that magnesium is more detrimental to the flotation process at far lower concentrations than calcium. Performing flotation with 45 ppm of calcium resulted in a comparable impact on the process as performing flotation with 7 ppm of magnesium. While calcium promotes the adsorption of starch onto the hematite and reduces entrainment, past an optimal dosage magnesium is promoting the adsorption of starch to everything in solution causing low grades and recoveries. It was found that the starch adsorption onto the hematite is strongly impacted by the presence of magnesium, suggesting that starch is collecting the magnesium and self-flocculating prior to adsorption onto the hematite. Thus, the presence of magnesium can significantly reduce the flotation performance far more than what would be expected from calcium.
... Most studies looking specifically at the mine tailings deposit have focused on its emerged part that infills the older Portmán Bay. Such studies address the infill history (Oyarzun et al., 2013;Gómez-Garcia et al., 2015), the potential interest of the tailings as a secondary ore (Matínez-Sánchez et al., 2013;Manteca et al., 2014), the geochemical characterization of the materials (Martínez-Sánchez et al., 2008, 2011 Science of the Total Environment xxx (xxxx) xxx García-Lorenzo et al., 2012, 2014a, and the pollution of soils and groundwater (Robles-Arenas et al., 2006;García-García, 2004;García-Lorenzo et al., 2014a, 2014b. In contrast, only two recent studies deal with the submerged extension of the mine tailings deposit. ...
... Section 1), ores were treated by froth flotation, a procedure requiring the mechanical crushing and milling of rocks and minerals, in concentration plants down to small grain sizes (i.e. <180 μm in "Lavadero Roberto" plant, Portmán, Fig. 1), and the subsequent segregation of particles according to their physical characteristics by taking advantage of the ability of air bubbles to adhere to specific mineral surfaces in a mineral/water slurry (Kawatra, 2011;Banos-González and Páez, 2013;Oyarzun et al., 2013). Chemicals such as caustic soda, sodium cyanide, sodium ethyl xanthate, copper sulphate and sulphuric acid (Banos-González and Páez, 2013) used in the process were also added to the tailings dumped at the sea. ...
Mining activities are essential to our society, but ore extraction and treatment produce waste that must be stored in safe places without harm to the environment. For a long time, seafloor disposal has been viewed as a cheap option with barely visible impacts. In Portmán Bay, SE of Spain, large amounts of tailings from open pit sulphide mining were discharged directly into the coastal sea over 33 years, thus forming a massive deposit that completely infilled the bay and expanded seawards over the inner continental shelf. Here we present the first multiproxy physicochemical characterization of the submarine tailings in Portmán Bay, mostly by using non-destructive techniques, also including pre-dumping and post-dumping sediments. Eight distinct sedimentary facies, grouped in four stratigraphic units, have been thus identified in a set of up to 4.3 m long gravity cores totalling more than 60 m. Geogenic and anthropogenic geochemical proxies consistently allow differentiating pre-dumping sediments from tailings. Potentially toxic metals if made bioavailable can reach high concentrations in units including or formed exclusively by tailings (i.e. up to 3455, 2755 and 1007 mg kg⁻¹ for Pb, As, and Zn, respectively). Some physical properties, such as magnetic susceptibility, are particularly useful as the tailings are rich in Fe-bearing minerals (>30% Fe in some layers). Estimated sedimentation rates show a strong gradient from proximal to distal locations, with rates in excess of 50 cm yr⁻¹ to less than 1 cm yr⁻¹. We ultimately document the history of the transformation of Portmán Bay from an almost natural state to new conditions after a long period of massive dumping of mine tailings. Our study provides guidance to further assessments in a context where the diversity of marine environments impacted by the disposal of mine waste is expected to grow in the near future.
... Hydrophobic minerals attach themselves to air bubbles and are carried to the surface of the flotation cell and recovered as floated products in mineral-water slurry. The hydrophilic minerals however stay in the liquid phase and are recovered as the sunk products [3]. Minerals or materials with same or similar physical properties (e.g. ...
... Graph of flotation recovery against time: (40 g mixture of plastics and soil, no tannic acid, 2 ml MIBC in 3dm3 flotation cell at 600 rpm for 5 minutes). ...
The Use of Froth Flotation for Selective Separation of Plastic Wastes from Soil Kofi Moro and Dorothy A. Dechie Abstract — In recycling of plastics, unless the goal is to form composites or materials having special properties, it is not advisable to mix plastics of different kinds because of the differences in their molecular weights and chain lengths. Hence, there is the need to separate these plastics when they are mixed before recycle can be done. This project investigated the selective separation of Polypropylene (PP), Polystyrene (PS) and Polyethylene terephthalate (PET) plastics out of soils using froth flotation. Pulverized samples were prepared from post-consumer plastic sources (PP, PS and PET) and soil and mixed uniformly to form a composite sample. The composite sample was subjected to froth flotation. Two tests were performed. A first test, where there was no addition of a depressant (tannic acid), and a second test, where there was addition of tannic acid to depress some of the plastics in order to selectively separate them. Recoveries from each test work indicated that, plastics are naturally hydrophobic and can be floated out of soils without modifying their surface properties. However, selective separations of the plastics were achieved when tannic acid was used to modify the surface properties of the plastic types.
... Hydrophobic minerals attach themselves to air bubbles and are carried to the surface of the flotation cell and recovered as floated products in mineral-water slurry. The hydrophilic minerals however stay in the liquid phase and are recovered as the sunk products [3]. Minerals or materials with same or similar physical properties (e.g. ...
... Graph of flotation recovery against time: (40 g mixture of plastics and soil, no tannic acid, 2 ml MIBC in 3dm3 flotation cell at 600 rpm for 5 minutes). ...
The Use of Froth Flotation for Selective Separation of Plastic Wastes from Soil Kofi Moro and Dorothy A. Dechie Abstract — In recycling of plastics, unless the goal is to form composites or materials having special properties, it is not advisable to mix plastics of different kinds because of the differences in their molecular weights and chain lengths. Hence, there is the need to separate these plastics when they are mixed before recycle can be done. This project investigated the selective separation of Polypropylene (PP), Polystyrene (PS) and Polyethylene terephthalate (PET) plastics out of soils using froth flotation. Pulverized samples were prepared from post-consumer plastic sources (PP, PS and PET) and soil and mixed uniformly to form a composite sample. The composite sample was subjected to froth flotation. Two tests were performed. A first test, where there was no addition of a depressant (tannic acid), and a second test, where there was addition of tannic acid to depress some of the plastics in order to selectively separate them. Recoveries from each test work indicated that, plastics are naturally hydrophobic and can be floated out of soils without modifying their surface properties. However, selective separations of the plastics were achieved when tannic acid was used to modify the surface properties of the plastic types.
... Flotation is the process studied in this thesis, which separates hydrophobic particles from hydrophilic ones in an aqueous slurry by means of rising bubbles. This separation technique has shown high applicability, for example, for the recovery of sulphides from silicates, coal from ash-forming minerals, silicates from iron ores, phosphates from silicates, among others (Kawatra and Darling, 2011;Wills and Finch, 2015). In this process, liberation and association play a key role in the process efficiency. ...
