5. September 2019 15:03
FAQ . General
1. What are electrically conductive solutions?
Electrically conductive solutions are solutions that are formed when an electrolyte is dissolved in a polar solvent, for example water. When the electrolyte is put into a polar solvent, it is dissolved into negatively charged anions and positively charged cations. When a direct current is applied to the solution, the anions are drawn to the positively charged electrode (or anode) and cations are drawn to the negatively charged electrode (or cathode). The clue is pretty much in the name; electrically conducting solutions are solutions capable of conducting electricity for manipulating the movement of the ions formed by dissolving the electrolyte.
2. What are the differences between electrowinning and electrorefining?
Electrorefining utilizes anodes comprised of impure metal. When the current is passed through the solution, the anode is corroded into the solution, causing the metal cation to migrate over to be re-plated onto the cathode. In electrowinning, on the other hand, the metal is already dissolved into solution hence the anode is inert.
3. What are the most commonly electrowon metals?
The most commonly electrowon metals are copper, gold, silver, zinc, cobalt, and nickel. Electrowinning as an extraction process is especially important for copper and silver. And with advanced “vortex” emew electrowinning technology the process is even more efficient ensuring the purity of metal can be plated to as high "Five Nines" (99.999%) along with the ability to deplete metals down to low concentrations (< 10 ppm).
4. How is electrowinning used for recycling and why?
Electrowinning can be used as a processing step for recycling of non-ferrous metals. Non-ferrous metals can be recycled infinitely without losing any of their properties. This feature makes electrowinning an ideal process to recover pure metals from complex, mixed metal feeds. In many cases, it is cheaper to recycle metals instead of mining ore, processing it and extracting the pure metals. And this is especially true considering continuously decreasing metal grades in existing mines and deposits.
5. What are the issues of the conventional electrowinning?
For the most part, electrowinning is a rather straightforward and simple process. As the process advances, the concentration of the target metal is depleted from the solution as the metal is plated onto the cathode. As the concentration of metal decreases, so-called depletion zones start to form next to the cathode. These are the zones where the concentration of the targeted metal is lower than in the bulk solution. This can be problematic as if there are other metal ions present in the solution they will start to plate onto the electrode resulting in impurities and low current efficiency.