ULF Cell—a Novel Design Principle for Pneumatic Froth Flotation Apparatus Utilizing Uniform Laminar Flow (original) (raw)
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A Review of Flotation Physical Froth Flow Modifiers
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Over the past few decades, the need to process more minerals while lowering capital costs has led to an increase in the size of flotation cells, e.g., 0.03 m3 to 1000 m3. However, this increase has created new challenges in the operation and design of industrial flotation cells, particularly in terms of froth removal, because the distance the froth must travel increases with an increase in the flotation cell diameter. This has a negative impact on recovery. Physical froth flow modifiers can be used to improve froth removal. Their major functions are to modify and optimise the flow of the froth, improve froth drainage, reduce dead zones, and improve froth flow and removal dynamics. Therefore, physical froth flow modifiers are discussed, evaluated, and compared in this paper. The literature indicates that physical froth flow modifiers such as crowders and launders are used extensively as industrial solutions to enhance froth transport and recovery in large flotation cells. Other modif...
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.
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.
Industrial evaluation of a new flotation mechanism for large flotation cells
Minerals Engineering, 2012
A new flotation mechanism was evaluated in the rougher flotation circuit at Collahuasi Concentrator Plant in Chile. For this purpose, the flotation mechanism FloatForce Ò was installed in one of three parallel rougher flotation lines, consisting of nine TankCell-160 (160 m 3) cells, while the other two lines operate with a conventional OK-mechanism. The evaluation was carried out based on a hydrodynamic and metallurgical characterization of the flotation circuits. Three overall samplings and mass balance adjustments for kinetic flotation characterization were performed. The residence time distribution RTD, of liquid and solids (per size class) was measured in the rougher lines using radioactive tracers. Thus, the effective mean residence time as well as the mixing condition in single flotation cells and along the rougher lines were evaluated. Also, measurements of axial solids segregation (per size class), axial mineral grade profiles, local superficial gas rate, bubble size distribution, bubble load and top of froth grades were performed in cells provided with both flotation mechanisms. The comparison of the rougher flotation operation with the FloatForce Ò and the conventional OK-mechanism is presented and discussed in this work.
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.
The effects of frother and collector distribution on flotation performance
Minerals Engineering, 2005
The distribution of frother reporting to the concentrate along a bank of cells and the adsorption of collector to valuable particles are important as they determine the froth structure and flotation performance. An understanding of this is required in order to formulate better reagent addition strategies. Techniques to measure the frother concentration in samples taken from industrial flotation circuits, including dynamic surface tension measurements, have proven inconclusive due to the low concentrations used and the effects of hydrophobic particles. In this study, a method of measuring the concentration of non-adsorbed reagents on a laboratory scale has been developed. Batch flotation experiments were carried out on an industrial sulphide ore. The adsorption of the collector (SIBX) and frother (Dowfroth 200) to the solid particles was determined by measuring the concentration remaining in filtered liquid samples taken from the concentrate and tails. Analysis was carried out using UV spectrometry and TOC analysis. It was found that 20% of the frother is lost in the presence of the SIBX and that after 2 min, 63% of the SIBX had adsorbed to particles. The results also showed that an increase in the initial concentration of SIBX, and an increase in the conditioning time yielded a higher concentrate grade.
Comparison of Jameson cell and jet diffuser flotation column
Physicochemical Problems of Mineral Processing, 2017
A Jet Diffuser Flotation Column (JDFC) is a newly designed flotation device which resembles the Jameson cell (JFC) in terms of operational principles, but it has an important difference regarding to the structural characteristics in the downcomer. The main difference of JDFC is the diffuser type of downcomer which has been designed using the hydrodynamic consideration and fluid mechanics principles. The aim of the design was to increase the device efficiency for coarse particle flotation. Therefore, the turbulence occurring at the end of the downcomer was reduced, and the detachment probability of the coarse particle decreased. In addition, a homogenous and stable foam zone in the cell was obtained. According to the experimental results carried out in a pilot scale showed that not only higher flotation performance in comparison to the Jameson cell was obtained specifically for the coarse particles but also the quiescent froth layer was acquired under the given conditions. In these e...
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.