How does melting gold work

Before gold can be sold in the form of coins and bars, raw gold must go through the smelting process. This process allows raw gold to be refined and cast into new shapes. The processed gold can be used for investment, provided it meets the conditions for investment gold. We explain to you how gold smelting works.
 

How gold coins and gold bars are made from raw gold

Investment gold is traded in the form of coins and bars. To make these, raw gold must be processed and impurities removed before the gold can be melted and poured.
 

Purity of raw gold

Raw gold that is mined is full of impurities including other metals such as silver and copper. By using mercury or cyanide, the metals can be separated from each other and other impurities disappear.
 
Because gold is a relatively soft metal, an alloy is made to make the gold a little harder. Before it can be melted, the gold and any other metals are weighed to create the right proportions and purities. For example, gold coins must contain at least 90% pure gold to be eligible for investment gold.
 

The process of melting and casting

After the gold has been purified and the proportions determined, it can be melted and cast. The melting point of gold is relatively low, 1064 degrees Celsius. The smelting furnaces that are used heat the gold in a constant manner. During the melting process, the last impurities can still be removed.
 
Once the gold is liquid, it can be poured into special molds. These are specifically designed to achieve certain weights, designs, and sizes. This step requires extreme precision to ensure the gold has the right aesthetic.
 

Finishing of the coins and bars

Finally, the gold coins and bars are finished and refined. During this step, the final product is polished to obtain the characteristic gold sheen. It is also possible that the gold is engraved or that other techniques are applied to uniquely finish or even secure the coins or bars.
 

Use of other metals in gold coins

Gold coins, mainly older gold coins, are combined with other metals to make them harder. In order to be used as investment gold, gold coins must have a purity of at least 90% gold. The other 10% can consist of silver, copper, platinum and zinc. This process strengthens the gold.
 
For example, the South African Krugerrand is minted in 22 karat gold (91.67% pure gold). The coin contains 1 troy ounce of gold, but is heavier overall because it is a copper alloy. This also gives this coin its characteristic red glow.
 

Melting down old gold

Not only raw gold can be melted. One way to recycle gold is to re-melt old gold and pour it into a mold. In the case of jewelry, the melted down gold is almost exclusively used to forge new jewelry.
 
It is also possible that bars are melted down so that they can be sold with new hallmarks, stamps or other markings. Switzerland melted down 5.7 tonnes of Russian gold in 2022 because, due to sanctions against Russia, Russian gold bars were not accepted by many investors. By melting them down, the gold bars became easier to trade again.