Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Electrorefining of Metals. Concentration Polarization and the Limiting Current Density

Illustration 3.2 Electrorefining of Metals, Concentration Polarization and the Limiting Current Density [Pg.98]

When a potential is applied to the electrodes, two processes take place. At the anode, the metal, along with its impurities, dissolves as positive cations into the electrolytic bath. These ions migrate to the negative cathode where they are discharged as metal. The impurities, such as iron, usually require a higher potential to be deposited, and consequently remain in solution. [Pg.98]

Electrorefining and concentration polarization (a) sample electrode pair and electrolytic bath (b) concentration gradients (c) flux due to diffusion and electrostatic potential. [Pg.99]

The maximum flux occurs when the concentration at the cathode has dropped to zero. Noting that the concentration at the anode is then twice the initial electrolyte concentration, C° we can write [Pg.100]

Let us apply this equation to a particular condition. Suppose that the electrodes are spaced 1 cm apart and the initial concentration of copper sulfate is 0.1 molar. Using the diffusivity for Cu++ listed in Table 3.3C we then obtain [Pg.100]




SEARCH



Concentration of metals

Concentration of polarization

Concentration polarization

Current concentration

Current limit

Current polarity

Current polarization

Densities of metals

Density limit

Density of current

Density of the metals

Density-concentration

Electrorefining

Electrorefining, of metals

Limitation current

Limited current density

Limited currents

Limiting concentration

Limiting currents

Metal concentration

Metallic densities

Metallization density

Polarization density

Polarization limit

The current density

The density

© 2024 chempedia.info