The grade or concentration of a mineral or metal in ore directly affects costs associated with mining as well as its subsequent beneficiation and extraction of precious components.
Under otherwise equal conditions, a lower grade means a higher cost per unit weight of extracted metal making high-grade ore deposits a crucial consideration for all types of investors in mining.
The grade of metal in ore changes over time and every year publicly traded and other mining companies routinely reevaluate, recalculate and report mineable reserves applying different variables, with commodity prices fluctuations being the most important contributor for upgrades/downgrades in reserves.
This analysis covers those currently active gold operations throughout the world that are separate reporting units and which have recent reserves evaluation figures disclosed by the owners/operators.
Why only reserves have taken into account? This is because mineral reserve is the part of mineral resource that demonstrated economic viability in current market conditions. Therefore, ore reserves are way less speculative than ore resources and relatively precisely reflect changes in economic “wellbeing” of mines.
For more accurate basis of comparison, gold operations have been split into underground and open-pit, since these mining methods utilize different techniques/equipment and it does make sense to identify “the best in the breed” gold operations within one mining category, first. In this research, focus has been made on ore grade in reserves while putting aside other crucial parameters like ore tonnage and volume of metal contained in ore.
Here is the list of the world’s top ten open-pit and underground gold operations in terms of ore grade, based on available 2014 data.
Data retrieved from the IntelligenceMine database, which provides researchers, investors and suppliers with up to date global mining market intelligence – mining and mineral exploration company reports; mine, project and processing facility reports; securities filings; an interactive mapper and much more. Learn more about IntelligenceMine.
1. With 44.1 g/t of gold in reserves, Fire Creek mine, owned by Klondex Mines and located in Nevada, United States, is believed to be the highest grade underground gold mine in the world.
2. Macassa gold operations, Ontario, Canada, owned by Kirkland Lake Gold Inc., is part of one of Canada’s oldest and richest systems. The Kirkland Lake Main Break system boasts production of 24 million troy ounces of gold over a span of 86 years and average historic grade of 16.5 g/t. With 22.2 g/t average gold grade reported in reserves, South Mine complex of Macassa operations holds the second place.
3. Kedrovka mine, Republic of Buryatia, Russia, owned by the local Zapadnaya Gold Mining company, enjoys the third highest grade underground mine and has a 22 g/t average ore grade in reserves. The mine is currently focused on the Osinovaya vein – a huge quartz vein, which has significant exploration upside potential with at least 100 identified veins.
4. Barrick’s Turquoise Ridge mine complex (Nevada, United States), fourth in our ranking with 16.9 g/t gold in reserves, has considerable untapped potential and is becoming a core operation for Barrick.
5. Part of Newcrest’s Gosowong mine complex in Indonesia, Toguraci mine sits at fifth with 16 g/t grade of gold in reserves.
6. Peruvian Orcopampa mine, owned by Buenaventura, is sixth with 15.8 g/t gold grade.
7. Dvoinoye mine holds seventh place with 15g/t gold, being a part of Kinross’ Kupol operations and located in the Far East of Russia within the Chukotka Autonomous Region.
8. Pinson mine, Atna Resources’ underground operation in Nevada, United States, eighth in our list with 13.8 g/t gold grade in reserves.
9. Midas mine of Klondex Mines (Nevada, United States), is ninth with 12.9 g/t gold grade.
10. Chilean Pimenton mine, owned by Cerro Grande Mining, is tenth with 11.1 g/t gold grade.
After we have identified highest grade underground gold operations, the second step is to lookup for the leader amongst them when apply two components combined; ore grade and volume of gold contained in reserves, which is derived from ore reserves tonnage in-situ and grade (see Figure 1).
Figure 1. Grade/contained gold relationship for the top 10 highest grade underground mines.
As shown in Figure 1, Barrick’s Turquoise Ridge production unit is out of competition, being both high-grade and high-tonnage underground gold mine operation.
As can be seen, four Polymetal’s open-pit gold mines in Russia are in the top list, which is remarkable achievement.
Albazino and Gounkoto mines are the leaders amongst highest grade open-pit operations when consider ore grade and volume of gold contained in reserves, combined (Figure 2).
Figure 2. Grade/contained gold relationship for the top 10 highest grade open-pit mines.