Why is silver often refined by electrolysis rather than only by heating?

Silver is often refined by electrolysis rather than solely by heating because electrolytic refining provides the highest-purity metal product and ensures the most effective recovery of valuable impurities. While heating (pyrometallurgy) is used in earlier extraction stages, electrolytic refining is the preferred final procedure to achieve the high levels of purity required for commercial applications.12

During this process, silver is cast into an anode and immersed in an electrolyte solution with a cathode. As a direct current is applied, silver ions dissolve from the anode and deposit onto the cathode in a highly pure state, often reaching "three-nines" (99.9%) or even "four-nines" (99.99%) fine. Furthermore, this method allows for the efficient separation and recovery of other precious metals, such as gold and platinum-group metals, which remain as insoluble residues or slimes in the refining tank. In contrast, relying only on heating would not achieve the same degree of precision in separating these valuable components or reaching such high purity levels.312