scholarly journals DETERMINATION OF THE DEPENDENCE OF THE SIZE OF THE FLOATED PARTICLES ON THEIR PROPERTIES AND THE HYDRODYNAMICS OF THE FLOTATION CHAMBER

2021 ◽  
Vol 2 (3) ◽  
pp. 230-238
Author(s):  
Sergey A. Kondratyev ◽  
Ksenia A. Kovalenko

It is noted that medium-sized particles have the highest flotation rate. Grains of the boundary classes of the size range have a reduced floatability, and they account for more than 50% of all losses of extracted minerals during flotation. The stability conditions of the particle - bubble flotation unit in the chamber of the foam flotation machine are considered. The effect of perturbations of the bubble surface on the size of the floated particles is studied. The amplitude of the initial deformation of the surface and the amplitude of the initial deformation rate of the bubble surface were determined depending on the energy of the turbulent pulsations of the environmental liquid. It is established that the rate of energy dissipation in the chamber of the flotation machine has a moderate effect on the size of the extracted grains. The influence of the surface properties of mineral particles and their mass on the upper value of the particle size range is studied. It is shown that the hydrophobicity of the surface has a significant effect on the size of the mineral particles that remain in contact with the gas phase. The main parameter that characterizes the effect of the hydrophobicity of the surface of the floated particles on the value of the separation force can be the value of the advancing contact angle.

2013 ◽  
Vol 721 ◽  
pp. 652-655
Author(s):  
Lin Lin Yang ◽  
Xiu Ying Tang ◽  
Jie Shi ◽  
Huan Zou ◽  
Xi Wang

This paper summarized the current advantages and disadvantages of flotation column, put forward a new type of flotation device - ring inflatable flotation machine, the overall structure of the device has been designed and patented. The study of the ring inflatable flotation machine has the advantages of low energy consumption and little abrasion, inflation rate, the probability of attachment and collision is high of mineral particles and air bubbles, selection and sweep the election time and frequency adjustment flexibility and large size range of separation.


Clay Minerals ◽  
1983 ◽  
Vol 18 (3) ◽  
pp. 313-323 ◽  
Author(s):  
R. Isherwood ◽  
B. R. Jennings

AbstractThe translatory and rotatory diffusion coefficients, electrophoretic mobility, permanent dipole moment, electrical polarizability and optical anisotropy factor for a crocidolite sol have all been measured in a single optical apparatus. Electrophoretic light-scattering and electrically-induced birefringence were the methods used, these being rapid and well-suited to particles in the micron and sub-micron size-range, where conventional electrophoresis is difficult. Electric birefringence offers a fast means of sizing mineral particles in suspension and the electrical polarizability and electrophoretic mobility have a common origin in such sols. This is discussed in terms of the surface-charge and electric double-layer characteristics of the particles.


2001 ◽  
Author(s):  
V. Aizenberg ◽  
P. Baron ◽  
K. Choe ◽  
S. Grinshpun ◽  
K. Willeke

Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.


2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 525 ◽  
Author(s):  
Mehdi Keshavarz-Ghorabaee ◽  
Maghsoud Amiri ◽  
Edmundas Kazimieras Zavadskas ◽  
Zenonas Turskis ◽  
Jurgita Antucheviciene

The weights of criteria in multi-criteria decision-making (MCDM) problems are essential elements that can significantly affect the results. Accordingly, researchers developed and presented several methods to determine criteria weights. Weighting methods could be objective, subjective, and integrated. This study introduces a new method, called MEREC (MEthod based on the Removal Effects of Criteria), to determine criteria’ objective weights. This method uses a novel idea for weighting criteria. After systematically introducing the method, we present some computational analyses to confirm the efficiency of the MEREC. Firstly, an illustrative example demonstrates the procedure of the MEREC for calculation of the weights of criteria. Secondly, a comparative analysis is presented through an example for validation of the introduced method’s results. Additionally, we perform a simulation-based analysis to verify the reliability of MEREC and the stability of its results. The data of the MCDM problems generated for making this analysis follow a prevalent symmetric distribution (normal distribution). We compare the results of the MEREC with some other objective weighting methods in this analysis, and the analysis of means (ANOM) for variances shows the stability of its results. The conducted analyses demonstrate that the MEREC is efficient to determine objective weights of criteria.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1976
Author(s):  
Tomasz Garbowski ◽  
Tomasz Gajewski

Knowing the material properties of individual layers of the corrugated plate structures and the geometry of its cross-section, the effective material parameters of the equivalent plate can be calculated. This can be problematic, especially if the transverse shear stiffness is also necessary for the correct description of the equivalent plate performance. In this work, the method proposed by Biancolini is extended to include the possibility of determining, apart from the tensile and flexural stiffnesses, also the transverse shear stiffness of the homogenized corrugated board. The method is based on the strain energy equivalence between the full numerical 3D model of the corrugated board and its Reissner-Mindlin flat plate representation. Shell finite elements were used in this study to accurately reflect the geometry of the corrugated board. In the method presented here, the finite element method is only used to compose the initial global stiffness matrix, which is then condensed and directly used in the homogenization procedure. The stability of the proposed method was tested for different variants of the selected representative volume elements. The obtained results are consistent with other technique already presented in the literature.


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