Marigold is a large run-of-mine heap leach operation with several open-pits,
owned and operated by Marigold Mining Company, a wholly-owned subsidiary of
SSR Mining Inc. Marigold is located in southern Humboldt County, Nevada, in
the northern foothills of the Battle Mountain Range, approximately 60
kilometers east of the town of Winnemucca and five kilometers
south-southwest of the town of Valmy.
In August 1989, the first gold doré bar was poured at the Marigold mill. In
1994, Marigold became a run-of-mine (ROM) heap leach operation.
Marigold uses standard open-pit mining methods at a current mining rate of
200,000 tonnes per day. The mine conducts conventional drilling and blasting
activities with a free face trim row blast to ensure stable wall rock
conditions. Electronic detonators are used to control the timing of the
blasthole detonation.
The Marigold processing plant combines industry standard ROM heap leaching,
carbon adsorption, carbon desorption and electro-winning circuits to produce
a final precious metal (doré) product.
All processing of ore, which is oxide in nature, is completed via the ROM
heap leach pad, which is a cost-effective method to recover gold. ROM ore is
delivered to the leach pad by haul truck and stacked in 6.1 meter to 12.2
meter lifts. At any given time, approximately 0.5 million square meters of
pad area are being leached.