Production
How is gold produced? Gold mining is an intensive process that requires careful and responsible management.
Understanding gold mining
Mining overview
The process of producing gold (in both underground and surface operations) can be divided into six main phases: finding the orebody; creating access to the orebody; removing the ore by mining or breaking the orebody; transporting the broken material from the mining face to the plants for treatment; processing; and refining. For further details, please visit www.trustingold.com
Small scale mining
Panning
Wide, shallow pans are filled with sand and gravel that may contain the rock and other material (because gold is denser than rock it quickly settles to the bottom). The silt is usually taken from a stream bed, often at the bend of the stream, or from the bedrock, where the weight of gold causes it to settle out of the water flow.
Large scale mining
Finding the ore body
A global, or regional, geological exploration programme identifies targets and undertakes exploration.
Open-pit mining
In open-pit mining, drilling and blasting may is generally needed to release the gold-bearing rock. Excavators then load the material onto the ore transport system.
Underground mining
In underground mining, holes are drilled into the ore body, filled with explosive and blasted. The blasted 'stopes' or 'faces' are cleaned before the ore is released ready for transportation out of the mine.
Processing
The most common means of recovering gold is the cyanidation process. Cyanidation involves the leaching of ore in a strictly controlled alkaline cyanide leach solution, after which the gold is then re-dissolved and subsequently smelted into doré bars that are shipped to the refineries. The residual waste rock is then generally recycled in land-fill or landscaping projects.
Refining
The doré bars are further refined to become as close to pure gold as possible, in the form of gold bullion bars. They are then given 'good delivery status', the international standard for quality, providing assurance that they contain the quantity and purity of gold that has been stamped on them.