Mercur Gold Project is a Carlin Type gold deposit situated in Utah, the US. Revival Gold acquired the past producing project in 2024 and is advancing the development of the property.
In March 2025, the company announced the results of a Preliminary Economic Assessment (PEA) on the project.
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The PEA projected that Mercur can produce 65.6 million tonnes (MT) of mineralised material at 0.60 grams per tonne (g/T) over a mine life of ten years.
The development of Mercur project will require around $208m for pre-production and as working capital. An additional $110m sustaining capital will be invested over the life of the mine (LOM).
Once operational, Mercur will produce 95,000 to 105,000 ounces of gold per year.
The study recommended further work to enhance the level of detail, potentially improve the PEA’s economic outlook, and mitigate certain risks associated with the project.
This includes additional drilling in critical areas, exploring potential new discoveries from exploration targets, conducting metallurgical testing, and performing geotechnical studies.
A Pre-Feasibility Study (PFS) on Mercur Gold Project will be carried out once the laboratory and field studies have progressed sufficiently and the Mineral Resource estimate has been updated.
Mercur Gold Project Location
The Mercur Gold Project is situated around 35-miles (57km) southwest of Salt Lake City, Utah. The site lies within the Camp Floyd and Ophir mining districts in the southern Oquirrh Mountains.
It is divided into four areas informally- Main Mercur, South Mercur, West Mercur, and North Mercur.
Overall, the 16,378-acre (6,628 hectares) property includes interests in 450 unpatented lode claims, three unpatented millsite claims, 475 patented mining claims, and 426 fee land tax parcels made up of surveyed lots and six Utah state metalliferous minerals leases.
History
Mercur was the first Carlin-type gold deposit identified and mined in the Great Basin, western US. The property saw four mining phases, starting with silver extraction in 1870-1881.
In the 1970s and early 1980s, Getty Oil and Homestake Mining consolidated land in the area, leading to the development of the Mercur open pit mine and CIL mill complex by Getty in 1983.
Barrick Gold later acquired the mine, adding heap leach and pressure oxidation circuits. Between 1983 and 1998, Getty and Barrick produced 1.49 million ounces of gold.
From 1890 to 1988, 41.4 million tons (37.6 million tonnes) of mineralised material were mined from the property, yielding 3.49 million ounces of gold, with 2.61 million ounces recovered.
In 2011, Rush Valley Exploration identified a remote sensing anomaly in the West Mercur area, suggesting potential gold deposits. Ensign acquired RVX properties in 2020, expanded land holdings, evaluated historical data, and conducted extensive sampling and drilling.
In April 2024, Revival Gold signed deal to acquire all issued and outstanding shares of Ensign. The transaction closed in May 2024.
Geology and Mineralisation
The Mercur Project covers a significant portion of the Ophir anticline, a north-northwest trending, doubly plunging fold that reveals a thick sequence of Mississippian carbonate platform stratigraphy.
The primary host for gold mineralisation is the approximately 1,000-m-thick Mississippian Great Blue Limestone, divided into the Lower Great Blue Member, the Mercur Member, the Long Trail Shale Member, and the Upper Great Blue Member.
Gold mineralisation along the east flank of the Ophir anticline, including North, South, and Main Mercur, is found in the Mercur Member. On the west flank, in the West Mercur area, mineralisation occurs within the Upper Great Blue Member, near its contact with the overlying Pennsylvanian Manning Canyon Shale.
The gold deposits at Mercur are classified as Carlin-type, where micron-sized gold particles are disseminated in silty, calcareous, and carbonaceous marine sedimentary rocks.
Mineral Resource Estimates
The Mercur Project PEA is developed considering Indicated Mineral Resources of 35.3MT grading 0.66 g/T gold, containing 746,000 ounces of gold.
Inferred Mineral Resources stand at 36.2MT grading 0.54 g/T gold containing 626,000 ounces of gold.
Mining and Recovery
The PEA projected a conventional open-pit, truck-and-shovel mining operation at Mercur. Gold extraction will be carried out via the cyanide heap-leach method.
According to the plan, 150-tonne haul trucks will be used to remove waste rock and transport it to designated waste rock storage facilities.
Leach material will be mined from open pits, and then pass through a crusher, and stacked on a heap leach pad for gold recovery.
Pit optimisation parameters were developed for an anticipated mining and processing rate of 20,000 tonnes per day. Pit designs were phased for both Main Mercur and South Mercur. The mining schedule assumes using a fleet with a maximum of 16 150-tonne trucks, one 29-cubic yard shovel, and one 30-cubic yard loader as primary equipment.
Test results indicate the mineral resource, including the Main and South Mercur pits, is suitable for cyanide leaching to recover gold.
Material from the Main and South Mercur pits will be transported to the central West Mercur processing site, crushed to 100% passing ½ inch at an average rate of 20,000 tons per day using a three-stage closed crushing circuit.
Pebble lime will be used for pH control before stacking onto the heap with a conveyor system. The heap will be leached with a dilute cyanide solution, and the pregnant leach solution will flow to a pond and subsequently to a carbon adsorption circuit.
Gold will be stripped using a modified pressure Zadra process and recovered by electrowinning. The resulting sludge will be treated to recover mercury before smelting to produce doré, which will be sold to a third-party refiner.
Activated carbon will undergo acid washing and thermal regeneration after each strip.
The gold project will receive power via an existing 43.8 kV transmission line, distributed using a 4.16 kV line, and stepped down as needed.
Emergency power will be provided by a diesel generator. Raw water for processing will be sourced from existing wells about 3miles from the West Mercur site and pumped to a head tank for distribution.
Contractors Involved
The Mercur Gold Project PEA report was prepared by Nevada’s Kappes, Cassiday & Associates (KCA) and RESPEC Company.
