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A Joint Venture
Manager
Golden Cycle Gold Corporation
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Leaching - Gold is removed from the crushed ore using the same basic process used in the Cripple Creek Mining District historically as well as throughout the world. The naturally occurring metals, including gold and silver, that are exposed on the broken faces of the crushed ore are dissolved by a dilute sodium cyanide process solution, a process called leaching.
At the Cresson Mine, the leaching of the gold is accomplished out-of-doors in a valley leach facility (“VLF”) - a valley area with clay and plastic liners upon which the crushed ore is placed for gold removal. The VLF can be thought of as a bathtub without a drain outlet, the sides and bottom of which are an impermeable double and triple liner system.
The crushed ore is placed in approximately 35-foot layers and a dilute solution of sodium cyanide, 100 parts per million, is applied using buried agricultural-type drip irrigation tubes to minimize evaporation. As the solution soaks through the ore, the process solution dissolves the gold and silver on the surface of the ore. The solution is captured at the lowest point of the VLF, the bathtub drain, and pumped into the recovery facility. The solution containing gold is called “pregnant” solution.
The Cresson Project VLF is operated with no external ponds for leach solution. Rather, the solution is contained within the pore space of the ore until pumped out much as ground water is pumped from porous bedrock. Because the VLF is a zero discharge, closed system, a significant excess capacity to accommodate large precipitation events is built into the VLF. A comprehensive water monitoring system is necessary to maintain the water balance in the pad to function as a zero discharge facility.
PO Box 191, Victor, CO 80860 719-689-4022 info@ccvgoldmining.com