In the early 1930’s, Edward Knight and Emmet Chase discovered the valuable gold deposits beneath Golconda, Nevada. Initial production took place in 1938 and overall output was promising. In 1993, Nevada Gold Mines (NGM) began operations at the Turquoise Ridge Mine in Golconda. Approximately 6 million ounces of gold has been extracted from this facility to date with an additional 7 million to be obtained in the future.

The gold extracted from the Turquoise Ridge Mine contributes to technological advancements including computer chips, smart phones, semi-conductors and the aerospace industry. The gold attained will not only benefit these areas, but ultimately contribute to overall economic security in North America by diminishing the dependence on foreign resources.

An expansion of the mine was required to increase production, ventilation, gold extraction and demand in the future. At a depth of 3,200 feet underground, the expansion is located in the deepest mine shaft in Nevada. Knowing the shaft would be in a moist environment, thousands of feet below the surface, a reliable form of corrosion protection was necessary to achieve the required 30-year life-cycle. Hot-dip galvanizing proved to be the best option due to its proven performance in a variety of corrosive environments. Other coating systems would be more expensive, require routine maintenance and have high VOC’s destructive to the environment. The brattice cages that guard the production and service shafts, load pocket steel in the underground material loading areas, handrails in the loading areas and set steel was galvanized for protection.

Throughout the project, the team experienced challenges that required effective communication across the project team. Some of the fasteners had to be welded to the structural steel prior to galvanizing. To meet this challenge, the fasteners were coated with silicone to prevent the zinc from adhering to threaded connections.

The impact of the expansion will be seen through many different avenues in the years to come. Since mining is the primary industry in the area, the project greatly impacts the local labor market and economy. It will provide a 40% increase in ore extraction and improve ventilation by 35% while reducing heat exposure and diesel particles. Shaft No. 3 will allow for an additional 200,000 ounces of gold to be extracted yearly and benefit our economy, technology, and overall way of life. Lastly, it will allow for another 15 years of viable operations and ventilation for the customer.