A gold dore bar, also known as a dore bar or dore bullion, is an intermediate product in the gold refining process. It is a semi-pure alloy of gold and various other metals, typically including silver, copper, and sometimes small amounts of other elements. Dore bars are produced as a result of mining operations and contain a mixture of gold and impurities.
Here are some key points about dore bars:
Composition: Dore bars are composed of gold and other metals. The exact composition can vary depending on the source and type of mining operation. Typically, dore bars contain high percentages of gold (ranging from around 70% to 95% purity) along with varying amounts of silver, copper, and trace impurities.
Origin: Dore bars are usually produced at mining sites where gold is extracted from ore. Gold-bearing rocks or ores are processed through various methods such as crushing, grinding, and chemical treatment to extract the gold. The resulting gold-rich material is melted and cast into dore bars for transportation to a refinery.
Size and Shape: Dore bars come in various sizes and shapes, depending on the mining operation and processing techniques. They are commonly cast into rectangular or trapezoidal bars weighing anywhere from a few kilograms to several hundred kilograms. The size and shape of dore bars can be customized based on the mining operation’s requirements and transportation logistics.
Impurities: Dore bars contain impurities such as silver, copper, and traces of other metals. These impurities are often considered valuable byproducts and can be recovered during the refining process. The presence of impurities in dore bars is one of the reasons why they need to undergo further processing and refining to achieve higher levels of purity.
Refining Process: Dore bars are sent to specialized gold refineries for further processing and purification. The refining process involves various techniques such as melting, assaying, chlorination, smelting, and electrolysis to separate and remove impurities, resulting in refined gold bullion with higher purity levels.
Dore bars play a crucial role in the gold supply chain, serving as the primary raw material for gold refining operations. They represent a valuable commodity that undergoes further processing to produce high-purity gold bullion suitable for investment, jewelry production, or industrial applications.