A Review of Flotation Physical Froth Flow Modifiers (original) (raw)
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Froth recovery of industrial flotation cells
Minerals Engineering, 2008
The mass flowrate of particles (ton/h), entering the froth by true flotation, was evaluated from direct measurement of bubble load (ton/m 3 ) and gas flowrate (m 3 /h). This information, together with the concentrate mass flowrate, allowed the estimation of the froth recovery of floatable mineral in a 130 m 3 rougher flotation cell.
Scale-up in froth flotation: A state-of-the-art review
Separation and Purification Technology
Froth flotation has been one of the most important and widely used methods to concentrate minerals since its introduction over a hundred years ago. Over the last few decades, in order to process more mineral while reducing capital costs, flotation equipment has become exponentially larger. The increase in tank volume, however, has brought new challenges in the operation and design of industrial flotation tanks. This review analyses the literature on flotation tank scale-up for the first time, contrasting several techniques and approaches used in both historical and state-ofthe-art research. The study of flotation scale-up is crucial for the optimisation of industrial plant performance and the maximisation of laboratory-scale research impact. While important advances in our understanding of flotation have been achieved, large flotation tank design and scale-up has, to a large extent, remained in-house know-how of manufacturing companies. This review of the literature relevant to flotation tank scale-up has resulted in a new classification, dividing the scale-up literature into two main areas of study, namely "Kinetic scale-up" and "Machine design scale-up". This review indicates that current scale-up rules governing the design of flotation tanks focus mainly on pulp zone kinetic parameters and neglect the effects on the froth zone, despite the importance of froth stability and mobility in determining flotation performance. Froth stability and mobility are closely linked to the distance the froth needs to travel, which increases with tank diameter. Although including internal elements, such as launders and crowders, has been the industrial solution for enhancing froth transport and recovery in larger tanks, the design and scale-up of these elements have not been thoroughly studied. Gaps in our knowledge of flotation are discussed in the context of addressing the scale-up problem, considering froth transport and froth stability. Addressing these gaps will pave the way for the design and operation of large flotation tanks of enhanced performance.
Modelling of froth transportation in industrial flotation cells
Minerals Engineering, 2004
Modelling of froth transportation, as part of modelling of froth recovery, provides a scale-up procedure for flotation cell design. It can also assist in improving control of flotation operation. Mathematical models of froth velocity on the surface and froth residence time distribution in a cylindrical tank flotation cell are proposed, based on mass balance principle of the air entering the froth. The models take into account factors such as cell size, concentrate launder configuration, use of a froth crowder, cell operating conditions including froth height and air rate, and bubble bursting on the surface.
International journal of mineral processing and extractive metallurgy, 2022
The desire to design and develop machine with high versatile method of physically separating mineral particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in mineral/water slurry using indigenous materials is constantly evolving to meet specific requirements of specific industrial plant. Therefore, the aim of this study was to design and construct a 0.012 m 3 capacity laboratory froth flotation machine using locally sourced materials with the view to promoting indigenous technology in Nigeria. The construction was based on parameters established from literatures. The design was done using Auto-Cad version 7 software. The machine was built of different components which are corrosion resistant, easy to access and can be assembled and disassembled when the need arises. The machine was constructed such that its height can be adjusted to suite flotation characteristics of different materials. The machine was of height 1.5 m and designed to operate at batch condition. A flotation tank of capacity 0.012 m 3 holds the pulverized pulp mixture for flotation operation. The flotation tank was equipped with regulated speed agitator shaft and stirrer assembly to condition the pulverized pulp mixture. Regulated air flow from a 0.02 m 3 /min compressor was also applied to the mixture in the cell for effective hydrophobicity and hydrophilicity.
Froth Flotation – Fundamental Principles
Froth flotation is a highly versatile method for physically separating particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in a mineral/water slurry. The particles with attached air bubbles are then carried to the surface and removed, while the particles that remain completely wetted stay in the liquid phase. Froth flotation can be adapted to a broad range of mineral separations, as it is possible to use chemical treatments to selectively alter mineral surfaces so that they have the necessary properties for the separation. It is currently in use for many diverse applications, with a few examples being: separating sulfide minerals from silica gangue (and from other sulfide minerals); separating potassium chloride (sylvite) from sodium chloride (halite); separating coal from ash-forming minerals; removing silicate minerals from iron ores; separating phosphate minerals from silicates; and even non-mineral applications such as ...
Design and Development of a 0.012 m3 Froth Flotation Machine from Locally Sourced Materials
International Journal of Mineral Processing and Extractive Metallurgy
The desire to design and develop machine with high versatile method of physically separating mineral particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in mineral/water slurry using indigenous materials is constantly evolving to meet specific requirements of specific industrial plant. Therefore, the aim of this study was to design and construct a 0.012 m 3 capacity laboratory froth flotation machine using locally sourced materials with the view to promoting indigenous technology in Nigeria. The construction was based on parameters established from literatures. The design was done using Auto-Cad version 7 software. The machine was built of different components which are corrosion resistant, easy to access and can be assembled and disassembled when the need arises. The machine was constructed such that its height can be adjusted to suite flotation characteristics of different materials. The machine was of height 1.5 m and designed to operate at batch condition. A flotation tank of capacity 0.012 m 3 holds the pulverized pulp mixture for flotation operation. The flotation tank was equipped with regulated speed agitator shaft and stirrer assembly to condition the pulverized pulp mixture. Regulated air flow from a 0.02 m 3 /min compressor was also applied to the mixture in the cell for effective hydrophobicity and hydrophilicity.
Powder Technology, 1998
The recovery and grades of a coal flotation concentrate are significantly dependant on the water content of tile overitowing frotll. The drainage of water from the froth is associated with the coalescence and bursting of bubbles in the froth. This work was undertaken to investigate the possibility of regulating the performance of a flotation cell by using Image Analysis to define a desired bubble size in the concentrate, and subsequently to use measured deviations to control bubble coalescence by the compensating addition of suffactants. The image analysis was done on a transputer-enhanced Micro Vax computer off-line, using video images of experimental semi-batch runs. Individual runs were done using a single surfactant which had to act both as a frother and collector, two surfactants 2-eth) ! hexanol and Triton X-405 being used. Data fro,n the image analysis was interpreted together with experimental measurements of particle and water recoveries in terms of a previously formulated froth kinetic model. Correlation of the point rates of overflow of dry-mineral-matter-free (dmmf) coal in terms of the model produced physically plausible parameters.
An Insight into Research and Investigations on Froth Flotation
Flotation is combination of chemical, physicochemical and physical phenomena. It separates minerals on the basis of differences in surface properties. It is important to study the chemical and physicochemical properties of mineral surfaces. The process involves injection of air bubbles into a moving stream of aqueous slurry containing a mixture of particles. In the process only hydrophobic ores are collected on the bubble surface and exit the stream. According to the investigations reported by various researchers, it is envisaged to have adequate characterization of the system under consideration. Important factors in characterization includes solid phase, aqueous phase with solutes, gas or the second liquid phase, the three kinds of interface and interline, flow and force parameters and end products. The dispersed-air flotation looked preferable than dissolved air flotation. Gas hold up, superficial velocity and bubble size are important factors in column flotation.
A Review on Froth Washing in Flotation
Minerals
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 mechanica...