scholarly journals Optimization of Electric Field Assisted Mining Process Applied to Rare Earths in Soils

2021 ◽  
Vol 11 (14) ◽  
pp. 6316
Author(s):  
Carolina M. G. Pires ◽  
Jucélio T. Pereira ◽  
Alexandra B. Ribeiro ◽  
Haroldo A. Ponte ◽  
Maria José J. S. Ponte
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Current Density ◽  
Rare Earths ◽  
Optimization Technique ◽  
Electric Current Density ◽  
Non Linear Programming ◽  
Experimental Configuration ◽  
Soil Electric Field ◽  
Yttrium Ion

The extraction of rare earths has been studied worldwide, however some of these processes have a high cost and can cause negative environmental impacts. In order to mine these species from the soil, Electric Field Assisted Mining arises as an alternative to conventional mining processes. Therefore, the experimental parameters can be improved to obtain better results in the extraction of these species. The aim of this paper is to propose the optimization of the Electric Field Assisted Mining process of yttrium, to obtain the optimal experimental configuration to be applied in real soils. An optimization problem was defined to obtain the maximum extraction mass of yttrium ion (Y3+), considering the limitation for the quantity of electric current density. A hybrid optimization technique was used, based on the sequential application of genetic algorithms and non-linear programming. Different optimal process configurations were obtained, considering distinct limits for the electric current density. The best experimental configuration resulted in 0.5386 V cm−1 electric field strength and 0.10 mol L−1 electrolyte concentration. This condition was reproduced in real soil, which obtained a Y3+ electromining efficiency of 41.48%. The results showed that this technique is promising for the extraction of rare earth in real soils.

Influence of electric current density on the bactericidal effectiveness of pulsed electric field treatments

2006 ◽  
Vol 76 (4) ◽  
pp. 656-663 ◽  
Author(s):  
D.R. Sepulveda ◽  
J.A. Guerrero ◽  
G.V. Barbosa-Cánovas
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Current Density ◽  
Pulsed Electric Field ◽  
Electric Current Density

scholarly journals The effect of simplifications of a numerical mesh on the results of electromagnetic analysis of the Nuclotron-type cable

2018 ◽  
Vol 177 ◽  
pp. 08004
Author(s):  
Łukasz Tomków
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Current Density ◽  
Electric Current Density ◽  
Electromagnetic Analysis ◽  
First Case ◽  
Single Region ◽  
The Magnetic Field

The model of a single Nuclotron-type cable is presented. The goal of this model is to assess the behaviour of the cable under different loads. Two meshes with different simplifications are applied. In the first case, the superconductor in the cable is modelled as single region. Second mesh considers individual strands of the cable. The significant differences between the distributions of the electric current density obtained with both models are observed. The magnetic field remains roughly similar.

scholarly journals Magnetic field and electric current density distribution in the geomagnetic tail, based on Geotail data

2001 ◽  
Vol 106 (A11) ◽  
pp. 25919-25927 ◽  
Author(s):  
P. L. Israelevich ◽  
A. I. Ershkovich ◽  
N. A. Tsyganenko
Keyword(s):  
Magnetic Field ◽  
Density Distribution ◽  
Electric Current ◽  
Current Density ◽  
Current Density Distribution ◽  
Electric Current Density ◽  
Geomagnetic Tail

Gasdynamic Effects on Electric Current Density in Magnetogasdynamics

1962 ◽  
Vol 29 (4) ◽  
pp. 483-484 ◽  
Author(s):  
S. I. Pai
Keyword(s):  
Electric Current ◽  
Current Density ◽  
Electric Current Density

scholarly journals Time evolution of electric fields and currents and the generalized Ohm's law

2005 ◽  
Vol 23 (4) ◽  
pp. 1347-1354 ◽  
Author(s):  
V. M. Vasyliūnas
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Time Evolution ◽  
Time Scales ◽  
Current Density ◽  
Time Derivative ◽  
Electron Plasma ◽  
Displacement Current ◽  
Ohm’S Law ◽  
Ohm's Law

Abstract. Fundamentally, the time derivative of the electric field is given by the displacement-current term in Maxwell's generalization of Ampère's law, and the time derivative of the electric current density is given by the generalized Ohm's law. The latter is derived by summing the accelerations of all the plasma particles and can be written exactly, with no approximations, in a (relatively simple) primitive form containing no other time derivatives. When one is dealing with time scales long compared to the inverse of the electron plasma frequency and spatial scales large compared to the electron inertial length, however, the time derivative of the current density becomes negligible in comparison to the other terms in the generalized Ohm's law, which then becomes the equation that determines the electric field itself. Thus, on all scales larger than those of electron plasma oscillations, neither the time evolution of J nor that of E can be calculated directly. Instead, J is determined by B through Ampère's law and E by plasma dynamics through the generalized Ohm's law. The displacement current may still be non-negligible if the Alfvén speed is comparable to or larger than the speed of light, but it no longer determines the time evolution of E, acting instead to modify J. For theories of substorms, this implies that, on time scales appropriate to substorm expansion, there is no equation from which the time evolution of the current could be calculated, independently of ∇xB. Statements about change (disruption, diversion, wedge formation, etc.) of the electric current are merely descriptions of change in the magnetic field and are not explanations.

scholarly journals Electric Currents Connected With the Proton Flares of 7 July and 2 September, 1966

1971 ◽  
Vol 43 ◽  
pp. 417-421
Author(s):  
A. B. Severny
Keyword(s):  
Active Region ◽  
Field Strength ◽  
Magnetic Flux ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Conductivity ◽  
Electric Current ◽  
Current Density ◽  
High Energy ◽  
Electric Currents

It is observed that the change of the net magnetic flux associated with flares can exceed 1017 Mx/s, which corresponds according to Maxwell's equation to the e.m.f. ∼ 109 V which is specific for the high energy protons generated in flares. It is shown that this value of e.m.f. can hardly be compensated by e.m.f. of inductance which should appear due to the actually measured motions in a flare generating active region. The values of electric field strength thus found, together with measured values of electric current density (from rotH), leads to an electric conductivity which is 103 times smaller than usually adopted.

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