Waste piled up for a century becomes a resource
Tailings are the crushed rock left over once a mine has already taken out the metal it wanted, piled into dams and dumps for more than a century. The United States Geological Survey, the federal agency that tracks mineral supply, defines mine waste to include tailings by name, and states that recovering minerals from this waste can carry a smaller environmental impact than opening a new mine, since the rock has already been dug up and crushed once.
DRDGOLD, a company in South Africa, mines no new ore. Its entire business is reprocessing old gold tailings dams and dumps left behind by earlier mining. In the year ended 30 June 2026, it recovered 4,839 kilograms of gold, 155,577 ounces, at an average yield, the amount of metal recovered for every tonne processed, of 0.193 grams per tonne, about 193 milligrams of gold in every 1,000 kilograms handled, a MAOWCE calculation, a grade too low for any company to open a new mine and chase.
The group average is a company reported weighted figure across both operations plus smaller items, not a simple average of the other 2 bars shown.
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| Ergo Mining | 0.185 |
| Far West Gold | 0.218 |
| Group average | 0.193 |
DRDGOLD runs 2 operations, Ergo Mining and Far West Gold Recoveries, at different scale.
The group total is the arithmetic sum of the 2 operation figures shown beside it, not a 3rd independent measurement.
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| Ergo Mining | 18.97 |
| Far West Gold | 6.10 |
| Group total | 25.07 |
In December 2025, DRDGOLD took over a tailings dump called Kloof 2 from Sibanye Stillwater, another mining company. The transfer added 67 million tonnes to reserves and extended the life of Far West Gold Recoveries, the operation that received it, by 4 years, without a new tonne of rock dug from the ground. Niel Pretorius, chief executive officer of DRDGOLD, wrote in the company results that it is searching for tailings retreatment partners on 2 continents, Africa and South America, to recover both gold and copper.
Copper and cobalt tailings feed batteries directly
Gold has no role in an electric vehicle, but copper and cobalt do. Copper carries electricity through wiring, motors and chargers, and cobalt is a component in some battery chemistries. In the Democratic Republic of Congo, an operation called Metalkol RTR reclaims decades old copper and cobalt tailings from the Musonoi River valley near Kolwezi, using dredging and hydro sluicing, a method using high pressure water to break up old material instead of digging it out. The nameplate capacity of Metalkol, the maximum output the plant is built to produce, is approximately 100,000 tonnes a year of copper cathode and approximately 23,000 tonnes a year of cobalt in hydroxide form. Eurasian Resources Group owns 90% of the operation, and the government of the Democratic Republic of Congo owns the remaining 10%.
In 2026, Metalkol became the first tailings processing operation in the world to hold The Copper Mark, an independent assurance scheme covering copper, cobalt, zinc and molybdenum producers. The assurance body records the award date as 16 February 2026, and also records that Metalkol only partially meets its applicable criteria, with an improvement plan in progress, not a full pass.
How much metal is still left in old waste
A 2026 peer reviewed review of copper recovery studies, published in the journal Minerals, found tailings worldwide still hold between approximately 0.0024% and 1.11% copper by weight, depending on the site. Recovery efficiency in the weaker leaching systems the review examined ran around 30% to 40%, rising to near complete recovery under optimized conditions. The mining industry generates between 5,000 million and 7,000 million tonnes of waste every year worldwide, the review states, though that number describes new waste made today, not the tailings already sitting above ground for decades that DRDGOLD and Metalkol are reprocessing.