scholarly journals Effect of Bubble Surface Properties on Bubble–Particle Collision Efficiency in Froth Flotation

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 367 ◽  
Author(s):  
Shuofu Li ◽  
Kou Jue ◽  
Chunbao Sun
Keyword(s):  
Surface Properties ◽  
Froth Flotation ◽  
Surfactant Solution ◽  
Terminal Velocity ◽  
Bubble Surface ◽  
Particle Collision ◽  
Film Rupture ◽  
Collision Efficiency ◽  
Mineral Particles ◽  
Bubble Collision

In research on the particle–bubble collision process, due to the adsorption of surfactants and impurities (such as mineral particles, slime, etc.), most studies consider the bubble surface environment to be immobile. However, in the real situation of froth flotation, the nature of the bubble surface (degree of slip) is unknown. Mobile surface bubbles increase the critical thickness of the hydration film rupture between particles and bubbles, and enhance the collision between particles and bubbles. Sam (1996) showed that when the diameter of the bubble is large enough, a part of the surface of the bubble can be transformed into a mobile state. When the bubble rises in a surfactant solution, the surface pollutants are swept to the end of the bubble, so when the bubble reaches terminal velocity, the upper surface of the bubble is changed into a mobile surface. This paper analyzes the collision efficiency and fluid flow pattern of bubbles with mobile and immobile surfaces, and expounds the influence of surface properties on collision efficiency.

A CFD study of particle–bubble collision efficiency in froth flotation

2019 ◽  
Vol 141 ◽  
pp. 105855 ◽  
Author(s):  
Shuofu Li ◽  
M. Philip Schwarz ◽  
Yuqing Feng ◽  
Peter Witt ◽  
Chunbao Sun
Keyword(s):  
Froth Flotation ◽  
Collision Efficiency ◽  
Bubble Collision

The Use of Froth Flotation for Selective Separation of Plastic Wastes from Soil

2021 ◽  
Vol 6 (4) ◽  
pp. 135-138
Author(s):  
Kofi Moro ◽  
Dorothy A. Dechie
Keyword(s):  
Surface Properties ◽  
Polyethylene Terephthalate ◽  
Tannic Acid ◽  
Froth Flotation ◽  
Selective Separation ◽  
Composite Sample ◽  
Molecular Weights ◽  
Plastic Wastes ◽  
Chain Lengths ◽  
Selective Separations

  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.

Effect of turbulence dispersion on bubble-particle collision efficiency

2022 ◽  
Vol 177 ◽  
pp. 107374
Author(s):  
Ai Wang ◽  
Mohammad Mainul Hoque ◽  
Geoffrey Evans ◽  
Subhasish Mitra
Keyword(s):  
Particle Collision ◽  
Collision Efficiency ◽  
Turbulence Dispersion

Film Size During Bubble Collision With a Solid Surface

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Travis S. Emery ◽  
Satish G. Kandlikar
Keyword(s):  
Solid Surface ◽  
Froth Flotation ◽  
Bond Number ◽  
Film Drainage ◽  
Drainage Rate ◽  
Archimedes Number ◽  
Experimental Parameters ◽  
Bubble Collision ◽  
The Impact ◽  
The Relationship

The impact and bounce of a bubble with a solid surface is of significant interest to many industrial processes such as froth flotation and biomedical engineering. During the impact, a liquid film becomes trapped between the bubble and the solid surface. The pressure buildup in this film leads to the generation of a film force. The drainage rate of this film plays a crucial role in dictating the bouncing process and is known to be a function of the radial film size. However, radial film size is not an easily attained experimental measurement and requires advanced instrumentation to capture. The bouncing process has been characterized using nondimensional numbers that are representative of the bubble collision and film drainage phenomena. These are: Bond number (Bo), Archimedes number (Ar), Froude number (Fr), and the ratio of film force to buoyancy force (FF/FB). These numbers are used to define a predictive function for film radius. Experimentally validated numerical modeling has been implemented to determine the relationship between the four nondimensional numbers, and a quasi-static model is employed to relate the film force to the radial film size. Comparison of our experimental results is in agreement with the predicted film size within ±20%. From these results, the radial film size during bubble impact with a solid surface may be predicted using the easily measurable experimental parameters of bubble size, bubble impact velocity, and the liquid properties.

Effects of Pine Oil on Dynamics of Bubble in Froth Flotation

2014 ◽  
Vol 493 ◽  
pp. 155-160 ◽  
Author(s):  
Warjito ◽  
Indra Pranata Al Kautsar
Keyword(s):  
Bubble Dynamics ◽  
Froth Flotation ◽  
Terminal Velocity ◽  
Image Capture ◽  
Flotation Column ◽  
Pine Oil ◽  
Modify Surface ◽  
Three Stages ◽  
Processing Software ◽  
Bubble Movement

Dynamics of bubble in froth flotation have been studied. The purpose of this research is to study the effects of pine oil on the dynamics of small bubble in froth flotation. Dynamics of bubble is an important parameter which determines flotation eficiency. Acrylic pipe was setup as a flotation column and equipped with image capture and lighting equipments. Later on, bubble was generated by a nozzle. A different nozzle size and pine oil concentrations were used in this experiment. Eventually, the dynamics of the bubble were captured by camera and the images were then processed by image processing software. Therefore, bubbles size and its position can be determined. The results indicate that bubble movement can be divided into three stages: acceleration, deceleration and terminal velocity. It is also indicated that pine oil modify surface tension; hence the bubble size become smaller and its velocy decrease. Moreover, pine oil induces the bubble to reach terminal velocity faster then bubble in water wthout pine oil. Therefore, it can be concluded that pine oil affects bubble dynamics significantly.

scholarly journals Agglomeration-Flotation of Finely Ground Chalcopyrite and Quartz: Effects of Agitation Strength during Agglomeration Using Emulsified Oil on Chalcopyrite

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 380 ◽  
Author(s):  
Vothy Hornn ◽  
Mayumi Ito ◽  
Hiromasa Shimada ◽  
Carlito Baltazar Tabelin ◽  
Sanghee Jeon ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Air Bubbles ◽  
Flotation Kinetics ◽  
Collision Efficiency ◽  
Mineral Particles ◽  
Emulsified Oil ◽  
Flotation Recovery ◽  
Median Diameter

In flotation, the size of mineral particles is one of the most important parameters: when the size becomes fine, collision efficiency of the particles and air bubbles becomes low, causing low flotation recovery. To improve the collision efficiency and flotation kinetics, agglomeration using the emulsified oil of finely ground chalcopyrite (D50 = 3.5 μm) was carried out before flotation. In this study, the effects of agitation strength during agglomeration, kerosene dosage and potassium amyl xanthate (KAX) dosage on the flotation were investigated. Agglomeration using emulsified oil improved Cu recovery because the median diameter of agglomerate increased. With increasing agitation strength, KAX and kerosene dosages, Cu recovery was further increased. Agglomeration-flotation of a mixture containing chalcopyrite and quartz with 1:1 ratio (w/w, weight by weight) showed that Si recovery in froth was low and did not change with varying conditions (agitation strength, KAX and kerosene dosages); however, Cu recovery was significantly improved with increasing agitation strength, KAX and kerosene dosages, and thus the separation efficiency was improved.

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