How Is Silver Purified?

Silver is extracted from sulphide deposits using a series of processes such as flotation, electrolysis and oxidation. Air is pumped through a slurry of water and powdered ore during flotation. The metal sulphides sink to the bottom then different methods are used to purify the ore.

Silver containing copper ore is refined using electrolysis. The silver accumulates at the bottom of the tank and is then electrolysed in a solution of silver and copper nitrate to yield commercial-grade silver.

Zinc is removed by roasting the ore and treating it with sulphuric acid. The resulting residue contains lead, silver and gold, which are then melted and mixed with hot air and powdered coal. The gold and silver in the lead bullion is then extracted by using zinc. The gold and silver residue floats to the surface and is further purified by heating it to 1,450 degrees Fahrenheit. The lead in the residue is oxidized by this process called cupellation. The gold and silver are then separated using electrolysis followed by boiling them with sulphuric acid.

Silver is found in sulphide deposits containing copper, lead and zinc. Silver tarnishes easily because of its reaction with sulphur. It is a nontoxic metal with antibacterial properties.