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A Joint Venture
Manager
Golden Cycle Gold Corporation
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Recovery - The process solution with the dissolved gold and silver (i.e. pregnant solution) is pumped into the adsorption, desorption, and recovery (ADR) facility for recovery of the gold and silver.
The solution is pumped through tanks containing activated carbon (roasted coconut shell) granules which attract, or adsorb, the dissolved gold-cyanide complex. The process solution, now with no gold or "barren", is re-circulated to the VLF to start the leaching cycle over. Process solution is pumped into and out of the ADR at a rate of 13,500 gallons per minute.
Gold on the carbon is
removed, or stripped, using a hot alkaline solution. The gold-rich solution
is the piped to an electro-winning cell where direct electrical current is
applied to attract metals from the solution to a stainless steel wool
cathode, forming a solid, called mud, of gold, silver and impurities. The
mud is sent to the refinery furnace and heated to separate the gold and
silver from any non-metal substances. The resulting 98% gold-silver mixture,
or 16-18 karat gold, is called dore’. The dore’ is shipped to a refinery to
be processed into 99.9% pure gold, or 24 karat.
This process recovers about 70% of the gold contained in the ore. Because the leaching process dissolves only the gold and silver on the surface of the rock, some metals remain. To recover all the metals the rock would need to be crushed so finely that the process solution would not flow through it.
Activated carbon needs to be durable to successfully resist breakdown from the large volumes of water passed through it. Once the carbon has been reused a number of times, it is dewatered and sent to a metals recovery facility to recover any remaining gold and other metals.
The ore on the VLF is not removed once the gold has been recovered from its surface. More ore is stacked on top of the leached rock in successive 35-foot lifts. When leaching is complete with one section of the VLF, the pipes carrying the solution are removed and another layer of ore is stacked on top for the next level. The main solution pipes are reinstalled, and process solution is pumped onto the new area of ore.
PO Box 191, Victor, CO 80860 719-689-4022 info@ccvgoldmining.com