The process of electrolysis is one in which an ion, in the form of a solution or a molten salt, completes an electrical circuit between one electrode and another. The two electrodes are called a cathode and an anode, which are negatively and positively charged, respectively. The electrodes attract oppositely charged ions, which means a cathode attracts positive ions while an anode attracts negative ions. This process is circular and continuous, and it is a process that helps refine silver.
Extracting Metal From an Ore
The first part of silver electrolysis is extracting the silver from an ore. After digging an ore from the earth, a plant extracts the metal through a process called flotation separation. Ore is put into multiple cells in a plant and a chemical solution containing alkyl xanthates pours into the cell. This solution helps break apart the sulphide component of the ore and float it to the top of the liquid solution. The silver, though, is not completely separated at this point. The sulphide component is silver sulphide and must be treated further.
The sulphide concentrations that result from the flotation separation process have to be treated further by a process called polymetallurgy. This is a form of smelting, which means that a metal sulphide gets treated to very high temperatures. During this process, the sulphide oxidises, producing sulphur dioxide. This also leaves behind molten metallic silver. In a plant, this sulphur dioxide is hazardous, so the gas is captured and converted into its acid form.
One way that plants that employ metallurgy extract certain metals is to use the basic process of electrolysis. They use both a cathode and an anode to provide a path for a direct current to pass through. What happens in this process is that silver deposits are collected on the cathode. This process is used quite often and can be part of a larger scale operation within a plant. This means that more metal can be extracted at once.
Another method in the refining process involves electrolysis once again. Electrorefining involves taking a metal and dissolving it at the anode end of a cell. The dissolved metal then gets redeposited at the cathode. This is a very beneficial process because the silver becomes more purified and the process prevents impurities from tagging along. With silver, instead of massive amounts of metal forming on cells, branches of silver form and can easily be harvested because they do not have a very strong bond to the surface of the cell.