Because of mining, ores that are rich in silver have become obsolete for the most part. The silver today comes from ores that only possess a small amount of the metal. These amounts can range from about a few thousandths of an ounce per ton of ore to 100 ounces per ton. The metal is most commonly produced as a by-product of mining for other metals.
Once the primary metal has been extracted it is the waste that will contain trace amounts of silver. These wastes are treated with chemicals that react with the silver. The silver is then be extracted by electrolysis which is a process by which a compound is broken down by passing an electric current through it. Once the ore is roasted, the process of reduction obtains the metal. The extraction of metal from the roasted ore consists of two steps viz., the removal of the earthly impurities and reduction of the ore to the metal.
The Earthly impurities are removed by adding suitable substance called flux which when heated, combines with the earthly impurities to form easily fusible mass known as slag, is called flux. There are two types of fluxes; Acidic flux like silica (SiO2) is used to remove basic earthly impurities (gangue) such as lime (CaO) or MgO and basic fluxes like lime (CaO), magnesium oxide (MgO) are used to remove acidic gangue such as SiO2.
When a flux combines with the earthly impurities, an easily fusible mass is obtained which is called slag. The slag is lighter and insoluble in the molten metal. So it can be easily removed from the surface of the molten metal. Molten mixture of calcium and magnesium silicates forms slag. After removing the Earthy impurities, the metals are obtained from the roasted ore by the process of reduction. This can be either chemical reduction or electrolytic reduction processes. The choice of the method depends upon various factors.