Smelting

Smelting is the process of extracting precious metals from ore through high heat and chemical reactions. Though gold and silver are generally found in a more purified form than many other metals, they still often require smelting to remove impurities and to separate them from surrounding rock or other metals.

• Gold's Natural State: Gold often occurs in a relatively pure form, such as nuggets or flakes, but it can also be found combined with minerals in ore.
• Process: In gold smelting, the ore is crushed, then heated in a furnace with a flux (commonly borax or sodium nitrate), which helps to separate the gold from impurities.
• Purification: Since gold is unreactive, it doesn’t bond with the flux or other chemicals, allowing it to be collected in molten form. This molten gold is then cooled and solidified.

Gold is often further refined through electrolytic refining or aqua regia (a mixture of hydrochloric and nitric acid) to achieve higher purity.

• Silver's Natural State: Silver is frequently found combined with ores like galena (lead sulfide) or argentite (silver sulfide).
• Process: Silver ore is also heated in a furnace with a flux. Often, lead is added as a collector to help concentrate the silver and separate it from other impurities. This process is sometimes known as "cupellation."
• Cupellation: When lead is used, it absorbs the silver and other precious metals. The mixture is heated, and lead oxidizes to form lead oxide, leaving behind pure silver.

Unlike iron or copper, gold and silver smelting doesn’t usually require reducing agents because they are less reactive and don’t form strong oxides. This makes the smelting process simpler and often allows higher purity levels after the initial smelt.

Both metals may be further purified through additional processes like chlorination, electrolysis, or parting to achieve nearly pure gold and silver for commercial or investment-grade products.

At Auriz Refinery, We concentrate in smelting precious metals using Electronic induction furnace, the best environment-friendly approach to transform large volume of Gold and Silver into grains or bullion bars of various size and purity grades. In accordance to the specific client requirements and needs, our experts are capable of converting Gold and Silver of internationally accepted quality standards.