South Africa and the US host two of the world’s ten largest gold mines, while Indonesia, Russia, Papua New Guinea, Chile, Australia, and the Dominican Republic house the remaining. South Deep gold mine in South Africa has the largest gold deposits in the world. Here we will list the top ten biggest gold mines in the world based on contained gold reserves.
1. South Deep Gold Mine
South Deep gold mine is the largest gold mine in the world, by reserves. Located 45km south-west of Johannesburg in the Witwatersrand Basin, South Africa, South Deep is also the seventh deepest mine in the world, with a mine depth up to 2,998m below the surface. The managed mineral reserve at South Deep as of December 2018 stood at 32.8 Moz.
South Deep was known by the name Western Areas Gold Mine until 2000. Mining operations at the site were started in 1961. Goldfields became the owner and operator of the South Deep gold mine in 2006. The underground gold mine is operated through two shaft systems, known as the South Shaft complex and the Twin Shaft complex.
South Deep produced 157, 100 oz of gold in 2018, compared to 281,300 oz in 2017. The mine life of South Deep is expected to be extended up to 2092. The underground mine uses a combination of conventional drift and bench and low-profile mining methods.
The Upper Elsburg reef, the main target of the mine, is mined using the ventilation shaft headgear discharge bin. The semi-autogenous grinding mill in the milling circuit is used for primary and secondary milling. Ore milling is done by the two overflow ball mills and the tailings are stored in the centralized tailings storage facility.
Gold is recovered using four Knelson concentrators. Gold adsorption is conducted by an eight-staged carousel-type carbon-in-pulp circuit. The processing plant has a capacity of 220,000t a month.
2. Grasberg Gold Mine
The gold rush that is the Grasberg gold mine in the Papua province of Indonesia was discovered in 1988. The Grasberg mining operation consists of the Grasberg open-pit and four underground mines, namely DOZ, DMLZ, Big Gossan, and Grasberg Block Cave (GBC). It also includes an undeveloped ore body named Kucing Liar. The mine is operated by Freeport Indonesia (PTFI), a subsidiary of Freeport-McMoRan Copper and Gold (FCX). PTFI owns 90.64% of the Grasberg mining operation, while the rest (9.36%) is owned by the Government of Indonesia.
The open-pit operation started in 1990 and was expected to be completed by the end of 2019. Ore production at the GBC underground mine started in the third quarter of 2019. Ongoing expansions at the mine are expected to ramp up the production to 240,000t per day by 2022. The mine produced 2.69 million ounces (Moz) of gold in 2018, milling 178,100t of ore per day.
The ore undergoes primary crushing at the mine, before being delivered by ore passes to the mill complex for further crushing, grinding, and flotation. Grasberg’s milling and concentrating complex are the largest in the world, with four crushers and two giant semi-autogenous grinding (SAG) units processing a daily average of 240,000t of ore.
A flotation reagent is used to separate concentrate from the ore. The slurry containing 60-40 copper concentrate is drawn along three pipelines to the seaport of Amamapare more than 70 miles away from where it is dewatered. Once filtered and dried the concentrate containing copper, gold, and silver is shipped to smelters around the world.
Ore extraction from the Grasberg Block Cave underground mine began in H1 2019 and it is expected to produce an additional 270,000Moz of copper and 14Moz of gold over the mine life. Total undercutting in the underground mine as of July 2019 stands at 48,000m, while the number of active production blocks increased to three. Ore extraction increased to an average of 17,000t a day in December 2019.
Production is expected to subsequently increase to an average of 30,000t of ore per day in 2020, 60,000t in 2021, and 130,000t in 2023 from a total of five production blocks. The ore is transported to the processing facility by a fully autonomous underground railway system.
3. Olimpiada Gold Mine
Olimpiada gold mine, located in the Krasnoyarsk region of Eastern Siberia, Russia is owned and operated by Polyus Gold. The mine has proven and the probable reserve is estimated at 26Moz (28Mt grading 2.88g/t gold) as of December 2018. It employs a conventional open-pit method with the use of shovel and truck. The extracted ore is processed at two nearby plants with a combined annual capacity of 13 tonnes.
The first production at Olimpiada gold mine occurred in 1996. The mine produced 1.3Moz of gold in 2018. It was transitioned to autonomous machine operation in January 2019. Olimpiada mine is an open-pit mine with the ore stock-pied at the surface. The ore is mined from the Vostochny pits.
The mining operations currently include conventional open-pit methods. This comprises drilling and blasting, followed by excavation for removal of rock, and hauling. Drilling and blasting are undertaken using a standard truck-and-shovel operation. The company performed several operational activities at the mine, including the installation of new turbo-elevators at the SAG mills and implementation of a DK-1 crushing unit.
The operational activities are part of an ongoing expansion program to improve the annual throughput of the mill complex to 13.4Mt of ore. The expansion project will undertake optimization and modernization of crushing, grinding, gravitation/flotation, and BIO/leaching processes at the mill.
4. Lihir Gold Mine
The gold rush is called the Lihir gold mine, located 900km north-east of Port Moresby in the New Ireland Province of Papua New Guinea (PNG), which has been in production since 1997. It is owned and operated by Lihir Gold Limited (LGL), which was merged with Newcrest Mining in August 2010. Newcrest Mining currently owns and operates the Lihir gold mine. Lihir gold mine had in-situ gold reserves of 24Moz (330Mt grading 2.3g/t gold) as of December 2018.
Most of the ore extracted from Lihir is treated through pressure oxidation and conventional leaching. The mine produced 933,000 oz of gold in the financial year ending June 2019. Newcrest completed a pre-feasibility study for the Lihir pit optimization in February 2016. The mine is expected to produce 1Moz of gold in 2020.
In 2006, Lihir treated 4.3Mt of ore at an average grade of 5.14g/t gold, producing 650,811oz of gold. The total material movement was 56.2Mt, a record. The target for 2007 was to move over 60Mt of ore and waste, with an output of more than 800,000oz. As in previous years, low-grade ore was stockpiled for future treatment.
In the quarter of June 2019, the Lihir mine achieved the target of a sustainable mill throughput rate of 15Mtpa. The mine had a production of 933.000oz in the financial year 2019 and 187,245oz of gold in the March 2020 quarter. The quarterly gold output witnessed a 14% increase due to improved mill throughput.
5. Norte Abierto Gold Mine
The Norte Abierto gold mine, which is yet to commence production, is located in the Atacama Region of Chile. Norte Abierto, a 50:50 joint venture between Barrick Gold and Newmont Goldcorp, is developing the mine as an open-pit project. The mine was estimated to contain 23.2Moz of proven and probable gold deposits as of December 2018.
Two deposits named Cerro Casale and Caspiche that are located at a distance of 12km from each other, within the Maricunga Gold Belt of northern Chile will be mined as part of the project.
6. Carlin Trend Gold Mine
Carlin Trend gold mine operated by Newmont in Nevada, US, has combined proven and probable gold reserves of 12.46Moz and 4.87Moz respectively, as of December 2018, while the stockpiles reserves were estimated to be 1.25Moz.
Newmont started open-pit mining at Carlin in 1965, while underground mining was started in 1994. The open-pit mines include the Carlin, Emigrant, Gold Quarry, and Silverstar pits. The operation also includes four underground mines namely Carlin East, Deep Post, Chukar, and Leeville. The Carlin mine complex produced 927,000oz of gold in 2018, compared to 972,000oz of gold in 2017 but it remains a gold rush.
The Carling Gold trend is one of the world’s richest gold mining districts. It is a belt of gold deposits, primarily in Paleozoic limy sediments that are about 5 miles (8 km) wide and 40 miles (64 km) long, extending in a north-west direction through the town of Carlin, Nevada. Gold was first discovered in the 1870s, but there was little production until 1909 and only about 22,000 oz was produced through 1964. By 2008 mines in the Carline Trend had produced over 70 million oz of gold worth around the US $85 billion at 2010 prices.
7. Boddington Gold Mine
The Newmont-operated Boddington gold mine located near Boddington, Western Australia, first commenced open-pit operations in 1987 by extracting the shallow oxide ores up to 70m-deep below the surface. It became a gold rush. It was put under care and maintenance in 2001. Commercial production from the Boddington gold mine was restarted in 2009, with an expected mine life of up to 20 years.
The mine contained the largest gold reserve of 12.35Moz including 1.3Moz of gold contained in stockpiles as of December 2018. It produced 709,000oz of gold in 2018. Newmont invested approximately $500m in a significant expansion of the mine’s south pit in 2015, which is expected to extend the life of the mine until 2025.
The operation involves open-cut mining from two large pits and is expected to produce an average 850,000oz of gold and 30,000t of copper a year for more than 20 years. Ore containing copper and gold is crushed to a coarse size before the ore is sent to the treatment plant via a conveyor. At the treatment plant, the ore is crushed further and ground finely to slurry. The ore is initially processed by flotation, which produces copper/gold concentrate with 18% copper.
Fine liberated gold is recovered by processing flotation concentrates through a gravity circuit before it is dewatered and stored. It is then ship-loaded for delivery to the smelters. The residual gold content found in the flotation tailings is recovered through a carbon-in-leach circuit.
8. Mponeng Gold Mine
Mponeng gold mine located near the town of Carletonville, South Africa, is owned and operated by prospectors AngloGold Ashanti. The underground gold mine is also currently the deepest employing semi-autogenous milling after which a conventional gold leach process incorporating liquid oxygen injection is applied. The gold is then extracted employing carbon-in-pulp (CIP) technology. The plant conducts electro-winning and smelting (induction furnaces) on products from Savuka and TauTonaas well.
Production in 2007 fell 2% to 587,000 ounces compared with 2006. The various planned and unplanned work stoppages and safety initiatives conducted towards the end of the year combined with a decline in grade and reduced face advance contributed to the decrease in production. There was a 4% decline in the area mined in 2007 largely as a result of a 3% decrease in face length. Mponeng undertook extensive cost-cutting measures throughout the year. Gold production at the Mponeng mine in 2010 was 532,000oz.
9. Pueblo Viejo Gold Mine
Pueblo Viejo gold mine, located roughly 100km north-west of Santo Domingo in the Dominican Republic, is owned and operated by Pueblo Viejo Dominicana Corporation (PVDC), which is a joint venture between Barrick Gold (60%) and Newmont Goldcorp (40%). Its contained gold reserves as of December 2018 were 10.92Moz (127.9Mt grading 2.66/t gold).
The open-pit mine exploits gold resources from two major oxide deposits, namely Monte Negro and Moore, as well as from three other small deposits in a gold rush. Pueblo Viejo was brought into commercial production in January 2013. It produced 581,000oz of gold in 2018. The life of the gold mine is estimated to be more than 25 years.
The project is using open-pit mining in stages. Mining is initially being carried out at the Monte Negro deposit. Stripping will not be required as the ore is present near the surface. Thickeners equipped with Hawk’s sonar technology are being used to control the mining operation. The thickeners are optimized by controlling the bed level and monitoring other real-time settling conditions. The use of this technology will reduce the chemical and electricity costs of the project.
The project also uses Maptek I-Site technology to conduct surveys on various activities taking place at the mine site. The survey system keeps track and account of all the activities at the site and saves about 50% of the time taken to conduct a physical site survey.
10. Cortez Gold Mine
Cortez gold mine, located 100km south-west of Elko, in Lander County, Nevada, US, is owned by Barrick Gold. It contains 8.7Moz (145MT grading 1.87 g/t gold) of contained total gold, including 1.13Moz of proven and 7.59Moz of probable reserves.
Production from Cortez was started in 1969. The mine employs both open-pit and underground mining methods. Gold from Cortez open-pit, Pipeline, and South Pipeline deposits are extracted through conventional open-pit methods.
The Cortez Hills underground mine is operated by twin declines. The underhand cut-and-fill mining method is used to exploit the breccia ore. Barrick Gold produced 1.7Moz of gold from the Cortez mine in 2018.
So, the 10 most bountiful goldfields in the world. None from a predictable California gold rush or in South Dakota, South Carolina, Idaho, Utah, the Yukon, Arizona, Alaska in Canada but in the United States and Australia, there is a gold rush. The gold deposits indicated are incredibly impressive as is the gold production. The mining companies are prospecting the gold veins and mineral deposits through the earth and finding thousands of nuggets of gold and other precious metals through their mining operations. The gold discoveries are vast and have been going since the 19th century. From underground mines, many kilometers below the earth vast amounts of gold are found. The world’s primary gold is a mother lode. From gold panning to gold ore, gold prospectors have been working hard to find the world's gold. From hard rock, they have been searching for mineral deposits and gold discoveries.