Tailings as the Next Gold Frontier

A century of gold mining has left behind billions of tonnes of tailings

— waste rock that was too low-grade to process economically when it was

first mined. At today's prices, and with today's technology, a

meaningful fraction of that material is starting to look like ore

again.¹

Why Tailings Became a Frontier

For most of the modern mining era, tailings were a problem rather than

an asset. They occupied land, required permits, carried environmental

liability and — most relevantly — contained residual gold at grades too

low to recover profitably. The economics assumed that recovery rates

above 90 percent were the best achievable and that anything left in the

tails was gone for good.

That assumption has shifted on two vectors simultaneously. First, the

price environment. At US$2,000 per ounce the residual gold in a tailings

dam was rarely worth chasing; at US$4,000-5,000 the same material

suddenly has economic weight. Second, the technology stack. Fine-grind

concentration, bioleaching, advanced flotation and cyanide-alternative

chemistries have materially improved recovery rates for low-grade feeds.

The Payne Institute's 2024 State of Critical Minerals Report highlighted

the combined effect explicitly as one of the key opportunities in the

North American mining landscape.¹

The Technology That Changes the Math

The relevant processing advances cluster in four areas. Fine-grind

technology reduces particle size further than traditional ball-milling,

exposing locked gold to leaching solutions. Modern flotation circuits

remove more of the sulphide minerals that consume leaching reagents.

Bio-oxidation, particularly for refractory sulphide-hosted gold, now

delivers recoveries that were uneconomic twenty years ago. And

cyanide-alternative or cyanide-optimised leaching chemistries reduce

environmental footprint without sacrificing throughput.

Each technology by itself produces modest gains. Combined, they can

shift the practical recovery floor for tailings feeds from the 30-40

percent range that was common in the 2000s to something closer to 55-70

percent. That difference, applied to a multi-million-tonne tailings

inventory, can translate into hundreds of thousands of recoverable

ounces.

For investors, the key observation is that tailings projects typically

require smaller capital commitments than greenfield mines. The ore is

already on surface, the location is already permitted for mining

activity, and the workforce and utility infrastructure are in place.

Payback periods are therefore shorter, and IRRs at current gold prices

can be extremely attractive.

The geological and metallurgical risk profile is also different. A

tailings deposit is, in effect, a deposit that has already been mined —

the grade, tonnage and mineralogy are known with a precision that no

greenfield discovery can match. That converts much of what is normally

technical risk into execution risk, and execution risk in a brownfield

setting with existing infrastructure is materially easier to manage.

Brazil's Particular Opportunity

Brazil has an unusually rich inventory of historical gold tailings.

Long-running operations like Paracatu in Minas Gerais, the Jacobina and

Fazenda Brasileiro mines in Bahia, and the Pilar and Turmalina

underground systems in Minas Gerais have each accumulated decades of

tailings material. Revista Minérios' December 2025 sector review

highlighted tailings reprocessing and recovery from old sites as one of

the most active investment trends in the industry.²

The regulatory environment matters here. Brazilian tailings dam

management has been under intense scrutiny since the Brumadinho dam

failure in 2019, and the cost of compliance has risen sharply. For older

dams, reprocessing the material — effectively emptying the dam — can be

simultaneously an economic project and an environmental-liability

reduction. That dual benefit is unusual and can make tailings projects

more attractive than they would be on metal economics alone.

ESG and the License-to-Operate Dimension

Tailings projects also have a specific ESG story. Reducing the footprint

of historical dams, recovering gold that would otherwise remain locked

in waste, and doing so using modern cyanide-optimised or

cyanide-alternative processing can be credibly positioned as a

climate-and-community-positive activity. The Payne Institute's Supply

Chain Transparency and ESG Initiative has framed tailings recovery as

one of the cleaner growth paths available to the industry.¹

The license-to-operate dimension is particularly important for majors

with diversified global footprints. A mid-tier operator that can

credibly present tailings reprocessing as a sustainability win, while

also delivering incremental ounces, has an advantage in conversations

with state-level regulators, municipal stakeholders and ESG-sensitive

investors.

There is a community-relations angle as well. Tailings dams frequently

sit close to populated areas, and their continued existence is a source

of tension with nearby residents. A project that reduces dam volume

while generating local employment and tax revenue can reposition the

mining company's relationship with its host community in ways that few

other interventions can.

Economics at US$4,000 Gold

Hypothetical project economics make the point concretely. A tailings

inventory of 100 million tonnes grading 0.3 grams per tonne contains

roughly 965,000 ounces of gold. At 55 percent recovery and US$4,000 per

ounce, gross revenue potential is approximately US$2.1 billion. Capital

costs for a tailings-reprocessing circuit are typically a fraction of

what a comparable greenfield mine would require — on the order of

US$150-250 million for a mid-scale project. Payback can be two to four

years even at conservative recovery assumptions.

The comparison to greenfield exploration is the clearest way to see the

appeal. A 1-million-ounce greenfield discovery today requires years of

drilling, permitting an