Round Mountain

Overview

Round Mountain is located approximately 96 kilometres north of Tonopah in Nye County, Nevada. 

The first recorded gold production from the Round Mountain District was in 1906. Approximately 350,000 ounces of gold was produced from 1906 through to 1969. Commercial production commenced in 1977. Since that time, over 10.2 million ounces of gold has been produced from the mine. 

Barrick Gold Corporation completed a merger with Homestake Mining Company in 2001 thereby acquiring the Homestake’s 50% interest in the mine. Kinross acquired a 50% interest in 2003, a result of the Kinross, TVX Gold Inc. Echo Bay merger. 

Round Mountain is a conventional open-pit operation that uses multiple processing methods including crushed ore leaching (reusable pad), run-of-mine ore leaching (dedicated pad), milling of higher-grade ore, and the gravity concentration circuit. 

In 2011, the mine produced 275,000 ounces of gold.

Location

Nevada is a state located in southwestern United States. The name Nevada is derived from the nearby Sierra Nevada mountains, which means "snow-capped mountain range" in Spanish.

The establishment of legalized gambling and lenient marriage and divorce proceedings in the 20th century transformed Nevada into a major tourist destination.

In 2004, 6,800,000 ounces (190,000,000 g) of gold worth $2.84 billion were mined in Nevada, and the state accounted for 8.7% of world gold production.

Access to the site is provided by paved highway or by charter aircraft. A paved airstrip, suitable for small aircraft is maintained near the mine site. 

The mine is supported by the local communities of Hadley and Carvers, which provide most of the housing for mine personnel. Sierra Pacific Power Co. provides electrical power to the mine. There are sufficient surface and water rights to support all current and forecasted mining at the site. 

The mine area straddles the transition between the floor of the Big Smoky Valley and the adjacent Toquima Range. Mine site elevations vary between 5,800 to 6,800 feet above sea level. 

The Round Mountain Gold Mine lies within an arid, high desert setting. Average annual precipitation in the Big Smoky Valley is approximately five to seven inches with most of that total falling during the winter months (December – March). Snow is common at the valley floor, but rarely remains on the ground for more than a few days. Temperatures range from 10° to 105ºF.

Geology & Mineralization

The Round Mountain gold deposit is a very large, epithermal, low-sulfidation, volcanic-hosted, hot-springs type, precious metal deposit.

The deposit is underlain by highly deformed sedimentary rocks of Cambrian through Permian age that have been intruded and locally metamorphosed by several granitic plutons of Cretaceous age. These rocks are in turn overlain by a sequence of Oligocene to Miocene age rhyolitic ash-flow tuffs that were erupted from a number of exposed and buried caldera sources. 

The geology of the Round Mountain Mine consists of a thick sequence of intracaldera Oligocene ash flow tuffs and volcaniclastic rocks resting upon pre- Tertiary basement rocks. The caldera margin and caldera-related structures provided the structural ground preparation for the hydrothermal system that introduced gold mineralization. The primary host rocks for gold mineralization are the volcanic rocks. A minor amount of ore occurs in the Paleozoic rocks along the caldera margin. 

Gold mineralization within the Round Mountain deposit occurs as electrum in association with quartz, adularia, pyrite and iron oxides. Shear zone fractures, veins and disseminations within the more permeable units host the mineralization. Primary sulfide mineralization consists of electrum associated with or internal to pyrite grains. In oxidized zones, gold occurs as electrum associated with iron oxides, or as disseminations along fractures.

Mining & Operation

The Round Mountain gold mine currently operates as a conventional open pit that is approximately 8,200 feet long in the north-west, south-east direction and 5,000 feet wide in the north-east to south-west direction.

Mining is conducted on 35-foot benches by electric shovels and front-end loaders paired with 150, 190 and 240 ton capacity haul trucks.

Processing

Gold is recovered using four independent processing operations. These include crushed ore leaching (reusable pad), run-of-mine ore leaching (dedicated pad), milling and the gravity concentration circuit.

Most of the ore is heap leached, with higher grade oxidized ores crushed and placed on the reusable pad. Lower grade ore, ore removed from the reusable leach pad and stockpiled ore that was previously leached are placed on the dedicated pad. A gold recovery circuit produced a gold sludge that next gets smelted into dore.

The finished doré bullion is shipped to refineries in North America for further processing as per the agreements of established contracts of the participants of the Smoky Valley Common Operation.

Environment & Community

There are no known environmental issues at the Round Mountain mine site.