NVRO Metals Advances Commercial Deployment of the NVRO Process™ Through Successful Continuous Production Demonstration on Hecla Greens Creek Material
VANCOUVER, British Columbia, Aug. 28, 2026 (GLOBE NEWSWIRE) -- NVRO Metals Limited (TSXV: NVRO | OTCQB: ESGLF | FSE: YGK) ("NVRO Metals" or the "Company") is pleased to announce the successful completion of a continuous production demonstration campaign using material from Hecla Mining Company's Greens Creek operation in Alaska as announced on 22 April 2026.
The campaign forms an important part of the Company's collaboration with Hecla Mining Company to evaluate the NVRO Process™ as a potential commercial processing solution for Greens Creek tailings material. The campaign successfully demonstrated continuous operation using customer feedstock under representative operating conditions and generated engineering, operating and metallurgical data to support future commercial deployment and investment decisions.
Highlights
- Successfully completed 202 hours of continuous operation on Hecla Greens Creek material.
- Campaign was preceded by 57.5 hours of commissioning and process stabilization.
- Continuous operation was consistent with the Company's IDEAS™ digital process model.
- Approximately 97% sulfide oxidation achieved during the campaign.
- Approximately 70% reduction in solids mass achieved during leaching.
- Preliminary operating results indicate:
- approximately 10.6-times silver upgrading from flotation feed to NVRO Process™ leach product;
- approximately 10.8-times gold upgrading from flotation feed to NVRO Process™ leach product;
- Full independent laboratory assays and complete metallurgical reconciliation remain in progress.
- For more information, including important assumptions and requirement for independent accredited testing to be completed, see "Basis of Reported Grades and Comparability" below;
- Operational indicators are in line with the Company’s IDEAS modelled performance with process optimization continuing;
- The Greens Creek tailings are known to contain additional metals including zinc, copper and other critical metals. The recovery of these metals is being assessed as part of this campaign.
Advancing Commercial Deployment
The successful completion of the continuous production demonstration represents an important milestone in the commercialization of the NVRO Process™ and demonstrated continuous operations of the complete integrated process using customer feedstock under representative operating conditions.
Management believes the successful campaign substantially reduces technical risk associated with future commercial applications of the NVRO Process™ and strengthens the Company's ability to progress discussions with mining companies seeking alternative processing solutions for complex sulfidic tailings and ores. The campaign was intended to support the evaluation of a 35,000t commercial processing trial under the parties' Memorandum of Understanding (announced 8 July 2026).
Demonstrating Stable Continuous Operation
The principal objective of the campaign was to demonstrate the oxidation and recovery performance following continuous operation of the integrated NVRO Process™ using customer material under representative operating conditions.
The campaign was undertaken using the Company's μNVRO Production Demonstration Plant, which forms part of the Company's Rapid Deployment Pathway for evaluating customer feedstocks prior to commercial deployment. During the campaign the plant operated continuously for 202 hours, following 57.5 hours of commissioning and process stabilization, while maintaining operating conditions consistent with those predicted by the Company's IDEAS™ digital simulation model.
Calculated sulfide oxidation of approximately 97% indicates effective oxidation of refractory sulfide minerals and liberation of metals contained within them. Operational observations throughout the campaign were consistent with the Company's engineering expectations and exceeded previous pilot results. Management believes the campaign demonstrates that the chemistry, process control and operating philosophy developed through laboratory and pilot testing translate effectively to continuous operation.
Management believes the continuous operation supports an internal assessment that the NVRO Process™ has reached Technology Readiness Level 7. The next step in the Company’s process development is expected to be the installation of a full-scale industrial plant, advancing through subsequent TRL stages toward TRL 9, representing proven commercial operation. The Company has announced its proposed acquisition and development of the NVRO Metals Hub as the location for future commercial operations as announced 10 June 2026.
Preliminary Precious Metal Upgrading
Preliminary operating results indicate continued upgrading of precious metals through the NVRO Process™. Compared with the calculated flotation feed grade:
- Silver upgraded from approximately 169 g/t to 1,795 g/t, representing an overall upgrade of approximately 10.6 times.
- Gold upgraded from approximately 1.51 g/t to 16.3 g/t, representing an overall upgrade of approximately 10.8 times.
The campaign also achieved approximately 70% reduction in solids mass during leaching.
These preliminary results are reported alongside those from the March 2026 bench-scale campaign for reference. As previously disclosed, the March and August campaigns were conducted on different samples of Greens Creek material and should not be interpreted as directly comparable measures of process improvement.
Table 1: Preliminary silver and gold grades and upgrade ratios, March 2026 Bench Scale Test compared with the August 2026 Campaign.
| Stage | Silver (g/t) | Gold (g/t) | ||
| March 2026 | August 2026 | March 2026 | August 2026 | |
| Flotation feed (calculated head) | 98 | 169 | 0.99 | 1.51 |
| Flotation concentrate | 266 | 725 | 2.90 | 5.87 |
| NVRO Process™ leach residue | 554 | 1,795 | 6.54 | 16.3 |
| Upgrade: feed to flotation concentrate | 2.7x | 4.3x | 2.9x | 3.9x |
| NVRO Process™ Upgrade: concentrate to residue | 2.1x | 2.5x | 2.3x | 2.8x |
| Total upgrade: feed to residue | 5.7x | 10.6x | 6.6x | 10.8x |
The grades and upgrading ratios reported in this announcement are based on assays undertaken by Nagrom based on a subset of feed and end product samples. Independent laboratories continue to analyze samples collected throughout the campaign. Following receipt of the complete analytical dataset, the Company expects to complete full metallurgical reconciliation and release final results.
Next Steps
Following receipt of the remaining laboratory assays, the Company expects to:
- complete metallurgical reconciliation of the campaign;
- advance engineering and operating data;
- continue process optimization;
- produce representative product samples for downstream evaluation;
- and continue discussions with Hecla regarding the next stage of the evaluation program under the parties' Memorandum of Understanding.
Grant Freeman, Chief Executive Officer, commented: "Successfully completing continuous operation over 200 hours is an exceptional milestone achievement and a demonstration of the integrated NVRO Process™ using customer feedstock. I would like to thank the entire team for their dedication to this goal.
The consistency of the operating performance and the preliminary metallurgical results give us confidence that the process is performing in line with our engineering expectations. We now look forward to receiving the balance of the independent laboratory results."
About NVRO Metals Limited
NVRO Metals Limited is a clean technology company focused on the recovery of precious, base and critical metals from refractory sulfidic ores, concentrates and tailings. Through its proprietary NVRO Process™, centralized processing infrastructure and commercial deployment strategy, the Company is building a scalable critical minerals production, processing and recovery platform centred on the NVRO Metals Hub in Australia's Northern Territory while advancing customer programs and strategic partnerships internationally.
For further information, please contact:
Grant Freeman,
Chief Executive Officer
Investor Relations,
Investor Cubed +1-647-258-3310
Forward-Looking Statements
Certain statements in this news release constitute forward-looking statements within the meaning of applicable Canadian securities legislation, including statements regarding pending assay results, the preliminary grades and upgrade ratios reported and their confirmation by independent assay, expected upgrading of metal grades, continued process optimization, the achievement and timing of TRL milestones, the application of campaign data to the NVRO Process™ digital model, the Company’s acquisition of the assets underlying the NVRO Metals Hub and future full-scale installation at the NVRO Metals Hub. Forward-looking statements are based on management’s current beliefs and assumptions and are subject to known and unknown risks and uncertainties that could cause actual results to differ materially, including the risk that equipment or processes do not operate as anticipated, that assay results differ from operational indicators or from the preliminary grades reported in this news release, that the calculated head grade used to derive the upgrade ratios differs from grades determined on confirmatory assay, that feed material variability may affect results at different scales or locations, that the Company may not secure the financing required for a full-scale plant, that required permits and regulatory approvals may not be obtained or may be delayed, and that qualification milestones are not achieved within anticipated timeframes or at all. Readers are cautioned not to place undue reliance on forward-looking statements. The Company assumes no obligation to update any forward-looking statement except as required by law.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
