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Маслий, А. И.; Poddubnyi, N. P.; Медведев, А. С.

doi:10.1023/a:1025160207042

Cited by 2 publications

(10 citation statements)

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“…As to the rest, to make it simpler to compare the would-be results of the modeling of a circulation mode with the data we obtained in [1] in the absence of circulation in the present work we used the same collection of PFE thicknesses (0.3, 0.5, 1.0 cm) with the same values of parameters of the porous matrix as well as values of kinetic constants of the target reaction (deposition of metal) and the side reaction (hydrogen evolution). Also retained were the former, sufficiently high, volume velocity of the solution flow m v = 0.975 cm 3 s -1 and the former, fixed, value of the dimensional current density 0.92 A cm -2 (in a galvanostatic mode of the electrolysis).…”

Section: Procedures Of Calculationsmentioning

confidence: 96%

“…As a result, its change will hardly affect the dynamics of the metal redistribution in the PFE. It is precisely this, most simplistic, version of a circulation mode that we analyzed in [1].…”

Section: Dynamics Of the Filling Of A Porous Flow-through Electrode mentioning

confidence: 99%

“…The dynamic model of a PFE and the procedure of calculations that we described in [1] were altered to suit a circulation mode by means of taking into account the variation in the metal concentration at the inlet in the course of time period ∆ t following from the condition of balance with respect to metal ions…”

Section: Procedures Of Calculationsmentioning

confidence: 99%

“…In work [1] there was presented a dynamic model for a porous flow-through electrode (PFE) in the process of extraction of metal from a dilute solution, which took into account the fact that the specific surface area S v ( x ) , porosity ε ( x ) , linear velocity of the flow of solution u ( x ) , and mass transfer coefficient for metal ions k m ( x ) undergo variations in the course of the metal deposition inside the PFE. In the same work there were presented the results of calculations of the dynamics of variations that occur in the properties of the porous matrix and the metal distribution over the electrode thickness for the simplest but hardly used in real practice case of a concentration of metal ions at the inlet of PFE that remains invariant with time.…”

Section: Introductionmentioning

confidence: 99%

“…The straight-through mode is inferior to the circulation mode also with respect to the volume rate of the reprocessing of the solution at a fixed degree of the metal extraction [3]. 1 That is why in the present work we are 1 From the viewpoint of regularities that govern the effect of various factors on the specific features of the dynamics of the filling of a PFE with the metal being deposited, a straight-through mode with a high degree of the solution depletion is of independent interest, for in this case the role played by the profile of the concentration of metal ions in the determination of uniformness of the distribution of the metallic deposit inside a PFE increases considerably. We are planning to consider these questions (the effect of the velocity and direction of the solution supply) in an independent communication.…”

Section: Introductionmentioning

confidence: 99%

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Dynamics of the filling of a porous flow-through electrode, which is operating in a circulation mode, with metal

2005

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A model, developed previously for describing the filling of a porous flow-through electrode (PFE) with a metallic deposit, is used to demonstrate that, in contradistinction to a straight-through mode, a decrease in the concentration of metal in a circulating solution (approximately by an order of magnitude in the course of the time period required for filling a critical cross-section of PFE with metal) leads to a change both in the direction of the spatial redistribution of metal inside the porous matrix and in the dynamics of the variation of its basic parameters. In a straight-through mode, the metal distribution inside a PFE is defined by the action of two opposite factors (development of a surface inside the working layer L ef at the expense of the growth of the diameter of fibers and, vice versa, its shrinking at the expense of a decrease in L ef with time and the expulsion of the process of deposition of metal in the direction of the front end of PFE) and is characterized by nonmonotonous dependences of the current efficiency and the outlet concentration of metal on time. The predominant tendency in the case of a circulation mode is different: L ef rises with time, which leads to a displacement of the process of the metal deposition in the direction of the rear end of PFE (at rear solution input), increase of maximal amount of deposit by approximately 1.4 times at L > L ef , as well as to dependences of the current efficiency and the ratio between the concentrations of metal at the outlet and inlet of PFE that are monotonously decreasing with time. At the expense of a continuous variation of the effective working surface area of PFE and the mass transfer coefficient with time, the circulation mode is characterized by a nonlinear dependence of the logarithm of the metal concentration in the circulating solution on the electrolysis duration. A comparison of indicators that are characterizing the dynamics of the filling of a PFE with metal in the course of galvanostatic and potentiostatic modes of electrolysis is performed. It is established that the application of a potentiostatic mode of electrolysis under the conditions that provide for the predominance of the target reaction is accompanied by a slight decrease in the maximum quantity of metal, but a very significant decrease (by 5-6 times) in the specific spendings of electric energy.

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Section: Procedures Of Calculationsmentioning

confidence: 96%

Section: Dynamics Of the Filling Of A Porous Flow-through Electrode mentioning

confidence: 99%

Section: Procedures Of Calculationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dynamics of the filling of a porous flow-through electrode, which is operating in a circulation mode, with metal

2005

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Dynamics of copper electrodeposition onto fibrous carbon electrodes

2012

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Distribution of copper electrodeposited from a sulfuric acid solution onto fi brous carbon electrodes, copper deposition rate, and current effi ciency by the metal were studied in relation to the electrolysis duration, electrical conductivity of the electrode, geometric current density, and solution fl ow rate. The variation of the electrode thickness on which copper ions discharge at the limiting diffusion current at various solution fl ow rates and the electrode thickness on which the whole amount of oxygen dissolved in the electrolyte is reduced were calculated in relation to the solution fl ow rate and geometric current density. The main factors governing the distribution of copper across the electrode thickness and the electrolysis parameters from the beginning of the process till "clogging" of a part of the electrode by the metal were determined.Fibrous carbon materials (FCMs) are widely used in various fi elds of science and technology as a base for composite, electrode, ion-exchange, and catalytic materials [1-4]. One of promising and developing areas of their application is for electrodeposition of metals and alloys onto FCM fi bers and electrorecovery of metals from solutions formed in processing of mineral and secondary raw materials [5][6][7][8][9]. The effi ciency of electrochemical processes on FCM electrodes depends on the properties of a material, solution composition, electrolysis conditions (geometric current density, solution fl ow rate, mutual positions of current and solution fl ow vectors), and process organization scheme [5,10,11]. When a metal is deposited onto the FCM, its initial properties (reaction surface area, porosity) change, together with the linear fl ow velocity of the solution through the electrode, and the mass-transfer coeffi cient. Therefore, important and as yet not studied in detail is the effect of changes in these parameters on the electrodeposition dynamics of the metal, its distribution across the electrode thickness, and electrolysis parameters (current effi ciency by the metal and copper deposition rate) at various electrolysis durations.The goal of our study was to experimentally examine the metal deposition dynamics and the electrolysis parameters (distribution of the metal across the electrode thickness, current effi ciency by the metal, and its deposition rate) for the example of copper electrodeposition from a sulfuric acid electrolyte onto fi brous carbon electrodes (FCEs), whose properties are initially constant across their thickness, in relation to the geometric current density and solution fl ow rate. EXPERIMENTALWe used the following electrolysis scheme: a 250-ml portion of a solution containing (g l -1 ): Cu 0.16, H 2 SO 4 25, and (NH 4 ) 2 SO 4 80, subjected to electrolysis, was circulated at a constant rate between a vessel and an electrolytic cell; the electrical conductivity of the solution was 0.1 S cm -1 . To maintain the concentration of copper ions in the solution within a prescribed range (c Cu = 0.16 ± 0.03 g l -1 ), the main copper-plating elec...

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Cited by 2 publications

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Dynamics of the filling of a porous flow-through electrode, which is operating in a circulation mode, with metal

Dynamics of the filling of a porous flow-through electrode, which is operating in a circulation mode, with metal

Dynamics of copper electrodeposition onto fibrous carbon electrodes

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