The Nevada Division of Environmental Protection has announced it has decided to issue a renewed Water Pollution Control Permit to Nevada Gold Mines to allow the construction, operation, and closure of mining facilities at the Arturo Mine in Elko County.
No comments were received during the public comment period on the permit. NDEP’s final determination to issue the permit can be appealed until 5 p.m. April 24. The permit is scheduled to become effective on April 29.
The work planned at the Arturo Mine consists primarily of the construction of a new heap leach pad, associated process ponds, process buildings, ore stockpiles, an open pit mine, and two waste rock facilities. The permit allows the processing of up to 12 million tons of ore per year. Mill-grade ore will be shipped to Goldstrike for processing.
The new Heap Leach Pad 12 at Arturo will be south of the mine’s reclaimed leach facilities. It is anticipated that the leach pad will be constructed in two phases, covering a total area of about 8.4 million square feet. The pad will accommodate approximately 72 million tons of ore, reaching a height of about 300 feet.
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The plan is to excavate about 10 million tons of existing reclaimed leach pad materials and place the material on HLP 12.
The process pond system will be south of the leach pad and will include a pregnant solution tank and two double-lined ponds. The pond system capacity has been designed to provide storage for 5.5 to 8.1 million gallons of process inventory.
A 4,000-gallon-per-minute process plant will support the HLP 12 facility. The process building will be about 150 feet by 60 feet and will house one carbon column train with five individual tanks.
Based on metallurgical and economic considerations, a maximum of 5 million tons per year of mill-grade ore from the Arturo open pit may be processed by other NGM operations or sold to others for further processing off-site.
Two waste rock disposal facilities are planned to accommodate an anticipated 600 million tons of waste rock material from the pit expansion. The larger WRDF will have a maximum height of 615 feet.
Groundwater elevations at the Arturo Mine are influenced by the dewatering operations at the North Block Goldstrike Mine which have resulted in lowering the groundwater levels approximately 1,700 feet within an approximately 2.5 mile-wide northwest-trending zone that extends to near the center of the Arturo area.
Additional pumping at the Arturo Mine for processing activities and mine closure are expected to continue through 2034.
At the conclusion of dewatering activities, the pit lake is expected to reach equilibrium where inflow from groundwater and rainfall will balance evaporation, creating a hydraulic sink.
Most of NGM’s mines northwest of Carlin in the Carlin trend are in the northeast corner of Eureka County. The Goldstrike Mine is at the northern border of Eureka County. Arturo is north of Goldstrike, and is in the northwest section of Elko County.
The Arturo Mine has been intermittently operated for 30 years. According to a NDEP fact sheet on the mine, Cordex Exploration Company conducted exploration activities in the Arturo area from 1981 to 1983. The Dee Gold Mining Company obtained control of the mining claims within the area in 1983. In 1984, DGMC, with Rayrock Mines Inc. as the mine operator, began production with an open pit. In 1999, DGMC began underground mining of the Dee Deep North deposit from a decline in the bottom of the open pit. The open pit and underground operations were shut down in 2000 due to a period of low gold prices, and reclamation and closure activities were initiated.
Barrick Gold Exploration Inc. entered into an agreement with DGMC and began exploration at the DGMC property in June 1998. Glamis Gold Ltd. acquired Rayrock Mines Inc. in 1999. BGEI and Glamis Marigold Mining Co., successor in interest to DGMC, entered into an agreement in January 2005 and formed BDMV. Goldcorp Inc. acquired Glamis Gold Ltd. in 2006 as a subsidiary. In 2007, Goldcorp Inc. changed the name of Glamis Marigold Mining Company to Marigold Mining Company.
As a separate entity, Barrick Rossi Mining Venture (a mining venture between Barrick Gold Exploration Inc. and Meridian Rossi Corporation) began the Storm Underground Mine from a second decline in the bottom of the DGMC property open pit in 2006.
A joint venture between Barrick (60 percent) and Premier Gold Mines (40 percent) began commercial production at South Arturo in 2016. The mine produced 142,810 ounces of gold in 2017. The joint venture completed mining the Phase 2 open pit and began processing stockpiled ore, so production dropped after 2017.
The Phase 2 open pit was partially backfilled and the El Nino underground mine was developed in the Phase 2 area.
Barrick’s 60 percent ownership of Arturo became part of Nevada Gold Mines when Barrick and Newmont formed the joint venture in July 2019.
NGM and Premier celebrated the start of production at the El Nino underground mine with a gold pour in September 2019.
In April 2021 Equinox Gold Corp. completed its acquisition of Premier Gold Mines, and Premier’s gold projects in Nevada, including the 40% ownership of Arturo, were spun off into a new company, i-80 Gold.
In September 2021 i-80 Gold and NGM agreed to a property exchange in which NGM acquired 100 percent ownership of the Arturo Mine, while i-80 Gold acquired NGM’s Lone Tree and Buffalo Mountain properties.