New Approach to Quartz Coarse Particles Flotation Using Nanobubbles, with Emphasis on the Bubble Size Distribution

2019 ◽  
Vol 19 (01) ◽  
pp. 1850048
Author(s):  
Sabereh Nazari ◽  
Sied Ziaedin Shafaei ◽  
Mahdi Gharabaghi ◽  
Rahman Ahmadi ◽  
Behzad Shahbazi ◽  
...  

This study investigates the influence of bubble size distribution and operational parameters on the flotation behavior of quartz coarse particles. The parameters evaluated during this study include the different bubble size distribution, air flow rate and impeller speed. Experiments were conducted at three different bubble sizes: 110, 171 and 293[Formula: see text]nm as db(32). Then, the results were compared with common air bubbles of the conventional flotation process. The bubble size distribution was measured using a laser particle size analyzer (LPSA). Results showed that the recovery of [Formula: see text]m particles increased in presence of nano bubbles (NBs) up to 25% compared to the conventional flotation. The maximum recovery of 95.59% was obtained using NBs size of 171[Formula: see text]nm at the impeller speed of 900[Formula: see text]rpm and air flow rate of 30[Formula: see text]l/h. It was also indicated that NBs caused an increasing in flotation recovery for all the samples in any size ranges in comparison with the conventional method.

2005 ◽  
Vol 1 (3) ◽  
Author(s):  
Mohd Shamsul Anuar ◽  
Siti Masrinda Tasirin

Mechanically agitated fluid bed granulators with inserted impeller are currently favoured by the industry due to better particle mixing, heat transfer and effective particle growth. However, effects of operational variables such as impeller speed, atomising air flow rate and fluidising temperature on the physical characteristics of the generated granules are still not fully quantified. Scaling-up of industrial fluid bed granulation processes especially in the pharmaceutical industry are done empirically. In this paper, a study is described on the effects of impeller speed, atomising air flow rate and fluidising temperature on the flowability, moisture content, mean particle size and size distribution of the granulated cocoa-milk drink powder in an agitated fluid bed granulation process. Findings showed that when all the values of the three investigated operational parameters were increased, granules with better flowability characteristics, lower moisture content, smaller and more uniformed granules were obtained in the range tested.


Author(s):  
Abbas H. Sulaymon ◽  
Ahmed Abed Mohammed

The separation of emulsified kerosene in water (concentration 250-750ppm) was investigated in a bubble column15.6 cm diameter and 120 cm height. The effective behaviors of bubble characteristics (bubble diameter, bubble rise velocity and air hold-up) on the removal efficiency were measured by electroresistivity probe. The effects of kerosene concentration, air flow rate,bubble diameter, liquid height, liquid viscosity, NaCl concentration, and alum on the removal rate were found. The experimental results showed that the removal efficiency increased with increasing air flow rate (1.09-2.6cm/s) and decreased with increasing CMC concentration. The results also showed that adding anionic surfactants (SLES and SDBS) leads to increase removal rate. The the flotation process was found to be first order kinetics. New correlations of air holdup and bubble diameter using dimensionless groups were derived.


1982 ◽  
Vol 104 (2) ◽  
pp. 198-206 ◽  
Author(s):  
Y. Tsuji ◽  
Y. Morikawa

Plug flow of coarse particles was investigated experimentally in a horizontal pipe, in which a sub-pipe for secondary air injection was installed. Measurements were made about the plug motion, pressure drop, and transportation properties, and the roles of the main and sub-pipe air flow were clarified. The main air flow increases the number of plugs, while the sub-pipe air flow increases the plug velocity. The higher the main pipe air flow rate, the more regular the motion. The height of a stationary layer of deposited particles, which is built on the bottom of the main pipe, decreases with increasing the sub-pipe air flow rate. The pressure drop in the moving plug is quantitatively much smaller than that in the stationary packed bed of same particles.


Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1663
Author(s):  
Mengkun Li ◽  
Lintao Zhang

This work aims at figuring out the influence of gas bubble size distribution on the ladle stirring process. The work is conducted through three-dimensional (3D) numerical simulation based on the finite volume method. Mesh sensitivity test and the cross-validation are performed to ensure the results are mesh independent and the numerical set-up is correct. Two distributions, uniform and Log-normal function, are investigated under different gas flow rates and number of porous plugs. The results indicate that the results, e.g., the axial velocity and the area of the slag eye, have little difference for low flow rate. The difference becomes dominant whilst the flow rate is increasing, such as 600 NL/min. The Log-normal function bubble size distribution gives a larger axial velocity and a smaller slag eye area compared to the uniform bubble size distribution. This work indicated that, at a higher flow rate, the Log-normal function is a better choice to predict the melt behavior and the slag open eye in the ladle refining process if the bubble interaction is not considered.


2012 ◽  
Vol 26 ◽  
pp. 5-12 ◽  
Author(s):  
Canhui Xu ◽  
Weihua Gui ◽  
Chunhua Yang ◽  
Hongqiu Zhu ◽  
Yiqiu Lin ◽  
...  

2013 ◽  
Vol 45 ◽  
pp. 128-141 ◽  
Author(s):  
Jinping Liu ◽  
Weihua Gui ◽  
Zhaohui Tang ◽  
Chunhua Yang ◽  
Jianyong Zhu ◽  
...  

Author(s):  
А. Volnenko ◽  
◽  
А. Leudanski ◽  
Y. Apimakh ◽  
B. Korganbayev ◽  
...  

For separation of plastic wastes (polyamide (PA), acrylonitrile butadiene styrene (ABS) and polystyrene (PS), a flotation method is proposed. Using this method, the effect of concentration of surface-active substances (surfactants), which were used as polidocanol, sulphanole and a mixture of surfactants containing sodium laureth sulfate and diethanolamide, was studied. The research results analysis of the flotation separation of a mixture of crushed plastic wastes was carried out according to the calculated values of the extraction of a floated component ε and the purity of a concentrate β. It was noted that the maximum extraction of the floated component depends on the polymer and surfactant type. A mixture of surfactants at lower concentrations allows to achieve greater extraction of the floated component with less foaming ability. The research results on the extraction of polystyrene from the air flow rate at various concentrations of surfactants’ mixture show that the extraction has a maximum at a certain air flow rate. At low air flow rates, the working volume of liquid is not saturated enough with gas bubbles. If the optimal value of air flow rates is exceeded, many gas bubbles are formed that are not involved in the flotation process. The research results on the extraction of polystyrene from the aerated liquid layer height at various concentrations of surfactants’ mixture show that, at a low height of the aerated liquid layer, the probability of collision of a plastic particle with an air bubble is low and some potentially floated particles seek the bottom of an apparatus without having time to collide with an air bubble. When assessing the influence of liquid temperature on the flotation process, it was found that increasing the liquid temperature above 20°C leads to a sharp decrease in ABS and PS extraction. This is explained by the fact that the dependence of the surfactants’ foaming ability on the temperature is characterized by solubility curves and for most surfactants they have an extremum.


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