EnviroGold Global Limited has announced a technical advancement that, it says, is expected to significantly expand the addressable market for its proprietary NVRO Process, following a significantly improved understanding of sulphide pre-concentration dynamics within the process flowsheet.
This advancement is expected to improve project economics of the NVRO Process across a broader range of tailings deposits, including lower-grade tailings previously excluded under earlier screening criteria. Management believes this represents an important step in the company’s commercial strategy, increasing the number of potentially viable commercial opportunities and strengthening EnviroGold’s exposure to precious and critical metals at a time of elevated global demand and heightened supply chain focus.
Historically, EnviroGold applied two principal criteria when assessing whether a tailings deposit was a suitable candidate for the NVRO Process:
- Metallurgy amenable to the NVRO Process, specifically metal-bearing sulphides containing refractory precious and critical metals; and
- Sufficient metal value per tonne, historically in the range of approximately $350 per tonne, to support economic processing.
These criteria currently support a robust commercial pipeline, the company says, but they also exclude a large number of tailings deposits where bulk metal concentration was too low, even though meaningful silver, gold and other metal value remained locked within the sulphide fraction.
Using the company’s previously disclosed customer base case, the NVRO Process demonstrated:
- 125 t/h of solids feed;
- Upgraded to approximately 16.8 t/h of residue sold to smelters; and
- Representing an approximate 7.4 times concentration upgrade.
This outcome validated the core NVRO value proposition for precious and critical metal recovery and demonstrated the ability to produce a smelter-grade concentrate from tailings that were previously considered unviable, the company claims.
“EnviroGold intentionally avoided deposits below the above selection criteria, as material upgraded by NVRO alone would not be saleable without cyanidation, which is increasingly difficult to permit and inconsistent with the company’s environmental strategy,” the company stated.
EnviroGold’s sulphide pre-concentration dynamics significantly expands the company’s commercial opportunities, it says.
By selectively concentrating the metal-bearing sulphides before leaching, the NVRO Process can be applied more efficiently to select tailings deposits previously considered uneconomic, according to EnviroGold. This approach upgrades the metal into a smaller, higher-value stream and reduces the overall volume of material to be processed. As a result, pre-concentration has the potential to reduce capital intensity, improving project economics and expanding the NVRO Process target market.
Based on this work, EnviroGold has updated its site-selection framework to focus on:
- Metallurgy amenable to the NVRO Process (metal-bearing sulphides); and
- Sufficient total recoverable sulphides containing precious and critical metals.
This shift significantly expands the company’s addressable market by including lower-grade tailings deposits that contain significant precious and critical metal value within recoverable sulphides, particularly silver, whose strategic importance has been reinforced by strong industrial demand and elevated prices, it says.
Grant Freeman, Chief Executive Officer, said: “The work undertaken during the 2025 Optimization Program has meaningfully changed how we assess NVRO project opportunities. By effectively separating value from waste through pre-concentration, we can consider a broader range of tailings deposits that were previously screened out. This is an important milestone for EnviroGold, as it expands its addressable market, has the potential to improve project economics and increases our exposure to precious and critical metal prices. In testing conducted to date, the NVRO Process has achieved gold recovery of up to 99.55% and silver recovery of up to 98.96%.”
The post EnviroGold eyes commercial sulphide opportunities for NVRO Process appeared first on International Mining.