Doré Bar
Also: Doré, Doré Bullion, mine bar
Doré bars are pre-refined crude bars of gold and silver cast directly in mines or smelters, subsequently processed to fine metal quality in a refinery.
Doré bars (from French doré = gilded) are the immediate product of pyrometallurgical processing in gold and silver mines. After the host rock has been broken down by cyanide leaching or other processes, the concentrated precious metals are smelted and cast on-site into crude bars. These bars leave the mine and travel to the refinery, where they are refined to tradeable fine metal quality (≥ 995 ‰ for LBMA Good Delivery, often up to 999.9 ‰ fine gold).
Composition and Production
A Doré bar is not a pure precious metal, but an intermediate product with variable fineness. Depending on the deposit and processing method, it contains:
| Component | Typical range |
|---|---|
| Gold | 60–95 % |
| Silver | 5–35 % |
| Impurities (Cu, Pb, Zn …) | < 5 % |
The yield of gold and silver from a Doré bar depends on the precise fineness, which is determined by sampling (assay) prior to refining.
Journey from Mine Shaft to Market
- Ore extraction — mining by open-pit or underground methods (primary mining).
- Processing — grinding, flotation, leaching; precious metals are brought into solution.
- Smelting — precipitation and smelting into the Doré bar directly on the mine site.
- Transport & assay — secure transport to the refinery; sampling determines the exact content.
- Refining — electrochemical or chemical refining yields fine gold (999.9) and fine silver.
- Trading — the refined metal flows into bullion bars, coins or industrial applications; the current gold price and silver price serve as the settlement basis.
Significance for the Gold Market
Around 90% of annual mine production reaches refineries as Doré bars. The difference between the spot price of fine gold and refining costs (known as Treatment & Refining Charges, TC/RC) determines the revenue side for the mining company. The melt value calculator can be used to estimate the theoretical metal value of a crude bar based on its weight and fineness.
Doré bars are not a trading object for private investors — they meet neither the LBMA Good Delivery requirements nor the conditions for VAT-exempt investment gold. For the price development of historical precious metal prices, however, they are a central supply factor.
In Brief
Doré bars form the link between mine production and the fine metal market: only after refining in an accredited refinery does the tradeable fine metal emerge that corresponds to the global gold price.