Unlocking the Copper-Gold Challenge: RZOLV’s Latest Metallurgical Breakthrough Points to a New Pathway for Stranded Gold Value

Across the global gold sector, some of the most difficult ounces are not necessarily hidden deep underground. Many are already known, drilled, mined, stacked, crushed, stockpiled, or sitting in legacy leach pads. The challenge is not always discovery. In many cases, the challenge is metallurgy.

Low-grade copper-gold ores, spent leach pads, transition zones, stockpiles, and copper-bearing gold deposits can be difficult to process economically because copper interferes with conventional gold recovery systems. Copper can consume reagent, complicate downstream recovery, increase detoxification requirements, and force operators into more complex flowsheets. In cyanide circuits, elevated copper can create a dependency on additional process infrastructure, including SART plants, to manage copper-cyanide complexes and regenerate cyanide.

That is why RZOLV Technologies’ latest laboratory results are important.

The Company’s recent metallurgical work demonstrates that the RZOLV platform can recover gold from low-grade copper-gold complex ores while also identifying a potential pathway to manage copper interference before gold leaching. In practical terms, this means RZOLV may be able to help unlock value from materials that are often considered too complex, too low grade, too copper-rich, or too costly to process using conventional approaches.

A Different Kind of Gold Recovery Problem

Gold processing is often described in simple terms: crush the ore, leach the gold, recover the metal. But real-world deposits are rarely simple.

Many gold systems include copper. Some contain oxide copper, secondary copper minerals, mixed oxide-sulphide zones, transition material, or copper-bearing alteration assemblages. Others contain legacy heap leach material where cyanide has already recovered the easy ounces, leaving behind residual gold in a chemically and metallurgically complicated environment.

In these situations, copper can become a major problem. It may consume reagent before gold is fully recovered. It may slow leach kinetics. It may create downstream complications. It may force additional capital spending. It may also turn what appears to be a viable gold resource into a marginal or stranded asset.

This is particularly relevant for low-grade deposits and spent leach pads. At low grades, every cost matters. Reagent consumption, residence time, solution management, water balance, copper handling, and downstream recovery can determine whether material is economic or uneconomic. A process that can recover gold while reducing copper-related interference could therefore have meaningful industry relevance.

The RZOLV Result: Gold Recovery Comes First

The most important achievement in the latest testwork is straightforward: RZOLV recovered gold from copper-bearing complex ore samples.

The program evaluated two contrasting copper-gold composites. One represented higher-gold, lower-copper material. The other represented lower-gold, higher-copper material. Both are relevant because they reflect the kind of variable feed that can exist within real copper-gold systems.

The higher-gold, lower-copper sample achieved strong gold recovery by direct RZOLV leaching. This suggests that certain copper-bearing ores may not require pretreatment where direct recovery is already strong. In these cases, a simpler RZOLV flowsheet may be sufficient.

The lower-gold, higher-copper sample is arguably the more important strategic result. This material represents the more difficult metallurgical challenge: lower gold grade, higher copper content, and greater potential for copper-related reagent consumption. In this case, copper pretreatment followed by RZOLV leaching modestly improved gold recovery while also materially improving reagent efficiency.

That combination matters. It shows that RZOLV is not only recovering gold from copper-bearing material, but that the process may be adaptable. Lower-copper material may be processed directly. Higher-copper material may benefit from copper pretreatment before gold recovery. This points toward an ore-selective processing strategy, rather than a one-size-fits-all flowsheet.

Copper Pretreatment: Turning an Interference Problem into a Process Step

One of the most important findings from the testwork is that copper was selectively removed/recovered before gold leaching, with no measurable gold loss during the pretreatment stage.

This is a critical technical point. Copper removal is only useful if the gold remains available for recovery. If the copper pretreatment step dissolves or loses gold, it creates a new recovery problem. In the RZOLV testwork, gold assays in the pretreatment liquors were below detection limits, indicating that gold remained in the solid residue for subsequent RZOLV leaching.

That result supports a potential two-stage approach:

1. First, remove and recover a significant portion of copper from high-copper material.

2. Second, recovery of copper from the copper-bearing pretreatment solution

3. Third, retain the gold in the solid residue.

4. Fourth, leach the copper-depleted residue with RZOLV.

This approach could be particularly relevant for copper-gold deposits where copper is not the primary product but is present at levels that interfere with gold recovery economics. It may also be relevant for spent leach pads and legacy materials where copper has accumulated, mobilized, or complicated recovery in conventional cyanide systems.

Reducing Reliance on Cyanide-Based SART Plants

In conventional cyanide circuits, copper can create significant operational challenges. When copper dissolves into cyanide solution, it can consume cyanide, form copper-cyanide complexes, reduce leach efficiency, complicate gold recovery, and increase the need for solution management. SART plants (Sulfidization, Acidification, Recycling and Thickening) are often used to recover copper and regenerate cyanide in copper-bearing cyanide systems, but they add capital cost, operating complexity, technical risk, and process integration requirements.

RZOLV’s latest work suggests a different potential pathway.

Instead of relying on cyanide leaching followed by SART to manage copper after it enters the cyanide circuit, the RZOLV approach may allow copper to be reduced before gold leaching. This does not eliminate the need for future engineering, optimization, or economic evaluation, but it introduces a potentially important alternative concept: manage copper upfront, recover gold with a non-cyanide platform, and reduce reliance on complex cyanide-copper recovery infrastructure.

For operators evaluating low-grade copper-gold ores, this could be important. A process that avoids or reduces dependence on cyanide-based SART infrastructure may offer a simpler and potentially lower-impact pathway for certain materials, particularly where permitting, reagent handling, environmental risk, or capital intensity are major considerations.

Why This Matters for Stranded Deposits

The mining industry contains a large inventory of known but underdeveloped material. Some of it is stranded because grade is too low. Some is stranded because metallurgy is too complex. Some is stranded because prior cyanide processing recovered only part of the gold. Some is stranded because the material contains too much copper, too much acid-consuming gangue, or too much process variability.

These are not small problems. Around the world, companies hold deposits, stockpiles, heap leach pads, tailings, transition zones, and mixed ore domains that may contain recoverable gold but lack a practical, economic, or environmentally acceptable processing route.

RZOLV’s latest results suggest that the platform may have a role in this opportunity.

The ability to recover gold from low-grade copper-gold material could help reframe certain stranded resources. Material that was once considered too difficult, too low grade, or too copper-rich may warrant a fresh metallurgical review. In some cases, the key may not be discovering more gold. The key may be finding a better way to recover the gold that is already known.

Spent Leach Pads: A Potential New Application Window

Spent leach pads represent another important area of potential relevance. Many historical heap leach operations were designed around cyanide recovery of oxide gold. Over time, these pads may contain residual gold, partially leached material, copper-bearing zones, variable solution chemistry, or material that no longer responds efficiently to conventional leaching.

The challenge with spent pads is that they are rarely clean systems. They may include prior reagent exposure, altered mineral surfaces, copper mobility, complex solution chemistry, and uneven residual gold distribution. A non-cyanide technology that can operate under a different chemical regime and potentially manage copper interference may provide a new evaluation pathway for these assets.

For owners of legacy pads, the business case can be compelling if the metallurgy works. The material is already mined. Crushing and stacking costs may be partly sunk. Infrastructure may already exist. Permits, water systems, ponds, roads, power, and recovery facilities may be partially in place. If additional gold can be recovered without relying solely on conventional cyanide re-leaching, spent pads could represent an attractive secondary recovery opportunity.

RZOLV’s copper-gold results do not prove commercial pad recovery, but they do support further investigation. The results show that the platform can recover gold from copper-bearing material and that copper interference can potentially be managed. That is exactly the type of technical insight needed to begin evaluating spent pads, stockpiles, and other legacy gold-bearing materials.

From Metallurgy to Optionality

The larger significance of the RZOLV result is optionality.

Mining companies do not need one more reagent that only works on ideal material. They need tools that can expand the process envelope. They need technologies that can handle variable feed. They need flowsheets that can be adapted to real deposits, not just clean laboratory samples. They need ways to recover metals from material that has been left behind.

RZOLV’s latest results point in that direction.

The testwork suggests that lower-copper material may be amenable to direct RZOLV leaching, while higher-copper material may benefit from copper pretreatment followed by RZOLV leaching. That creates a flexible framework for evaluating copper-gold resources. Instead of rejecting a deposit or stockpile because it contains problematic copper, operators may be able to classify material by copper content, recovery response, and reagent demand, then route it through the most appropriate RZOLV-based flowsheet.

This kind of ore-selective approach is important because complex deposits are rarely uniform. A mine may contain zones that are clean enough for direct processing, zones that require pretreatment, and zones where copper recovery could become a potential by-product opportunity. RZOLV’s platform approach may allow those differences to be managed rather than ignored.

A Potential Step Forward for Cleaner Gold Processing

The gold industry is under increasing pressure to reduce environmental impact, improve recovery, lower costs, and extract more value from existing resources. Technologies that can recover gold without cyanide are attracting growing attention, but the bar is high. A viable alternative must do more than work on clean ore. It must demonstrate relevance to the difficult materials that operators actually face.

That is what makes this latest RZOLV result noteworthy.

The company has demonstrated meaningful gold recovery from low-grade copper-gold complex material, shown that copper can be selectively reduced before leaching, confirmed no measurable gold loss during pretreatment under the tested conditions, and demonstrated meaningful reductions in reagent demand. Those findings collectively support the possibility of a broader application window for the RZOLV platform.

More work is required. The current results are laboratory-scale. They are specific to the samples and conditions tested. Repeat testing, larger-batch work, continuous-flow validation, downstream recovery testing, environmental evaluation, and economic analysis will be needed before commercial application can be determined.

But as a metallurgical development, the result is important.

It suggests a potential route for recovering gold from copper-bearing materials that conventional systems may find difficult. It may reduce reliance on cyanide-based copper management infrastructure such as SART plants. It may create new options for stranded deposits, spent leach pads, and low-grade copper-gold resources. And it reinforces the idea that the next generation of gold recovery may be defined not only by new discoveries, but by better ways to process the resources already in front of us.

The Bottom Line

RZOLV’s latest copper-gold testwork is significant because it addresses one of the mining industry’s most persistent challenges: how to recover gold from low-grade material complicated by copper.

By demonstrating gold recovery from contrasting copper-gold composites, showing selective copper removal without measurable gold loss, and reducing reagent demand after pretreatment, RZOLV has outlined a potential processing pathway for materials that are often difficult, costly, or environmentally challenging for conventional cyanide systems.

For an industry looking to unlock stranded value, reprocess legacy materials, and reduce reliance on cyanide-intensive infrastructure, this could be an important step forward.

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Disclaimer

This article is for informational purposes only and does not constitute investment, technical, or commercial advice. The RZOLV results discussed are preliminary laboratory-scale results from specific samples and test conditions, and should not be interpreted as demonstrating commercial viability, mine-scale performance, or applicability to other ores, deposits, stockpiles, or spent leach pads without further testing.

Statements regarding potential applications, copper management, reduced reliance on cyanide-based infrastructure, reagent efficiency, scale-up, or commercialization may be forward-looking and are subject to technical, economic, regulatory, and operational risks. Additional testwork, process optimization, engineering, environmental review, and economic analysis will be required before any commercial application can be determined.