Resolve Technologies, Inc (TSXV: RZL; OTCCP: Rezolf; (FSE: S711) has reported positive preliminary laboratory results from initial scoping tests on selected samples of low-grade copper and gold compounds using its RZOLV™ platform.
Although conducted under unoptimized conditions, preliminary tests showed calculated head-sequence recoveries ranging from 82.3% to 94.8% for gold and 71% to 80% for copper. The program was designed as an early-stage laboratory evaluation and did not include systematic optimization of pre-treatment conditions, filtration parameters, reagent system, residence time, or other process variables.
The Company cautions that these results are preliminary in nature and may not represent recoveries that can be achieved under improved, continued or commercial operating conditions.
The laboratory software evaluated two selected composite samples representing different copper-gold relationships: one high-gold, low-copper composite and one low-gold, high-copper composite. The test compared direct RZOLV leaching to a sequential configuration of a proprietary RZOLV platform in which copper was first extracted in a pre-treatment step, followed by RZOLV gold leaching of the pre-treated tailings.
The company considers the results encouraging because they demonstrate efficient recovery of gold from copper-bearing materials under specific laboratory conditions tested, identifying a potential route for copper management through a separate pre-treatment step and designing a feed-specific flow chart. Copper is a relevant factor in many gold systems because it can affect reagent demand and filtration conditions and complicate the final recovery process.
Testing showed the following results under the conditions tested: The high-gold, low-copper composite achieved a calculated gold recovery of 94.8% by direct RZOLV leaching, and 89% after copper pretreatment followed by RZOLV leaching. The direct route therefore produced a stronger result for this selected sample, and pretreatment may not be necessary for similar lower copper materials where direct recovery is already strong.
The lower gold, higher copper composite achieved a calculated gold recovery of 82.3% by direct RZOLV leaching, and increased to 84.1% after copper pretreatment followed by RZOLV filtration. The pretreatment step extracts a significant portion of the copper in a separate process stream before gold leaching, supporting further evaluation of sequential copper and gold extraction for similar materials with a higher copper content.
Copper pretreatment resulted in approximately 71% to 80% copper extraction in the pretreatment fluids under the conditions tested.
No gold was detected in the pretreatment fluids under the analytical method used.
Reported RZOLV additions were approximately 27% to 64% lower in the pretreated tests compared to the corresponding direct filtration tests. Additional testing is required to confirm the mechanisms affecting reagent demand and optimize the integrated process.
The results support further testing to determine whether the low copper material selected may be suitable for direct RZOLV filtration, while the higher copper material selected may benefit from sequential copper pretreatment followed by RZOLV gold filtration. This is presented as a concept for further evaluation, not as a project flowsheet.
Since both copper and gold represent potential value streams, further work will evaluate the recovery of each metal into a salable product or intermediate and evaluate the technical and economic performance of the integrated process.
“These positive initial results are encouraging because they were achieved during the first laboratory evaluation of selected samples and prior to systematic optimization of the process,” said Duane Nelson, President and CEO of RZOLV Technologies. “Tests demonstrated robust gold recovery and sequential extraction of copper and gold in separate processing streams. The results support further evaluation of the feed-specific processing approach, including direct RZOLV filtration for selected low-copper materials and copper pre-treatment followed by RZOLV gold filtration for selected higher-copper materials.”
Mr Nelson continued: “Further work will focus on replication, process optimization, scale-up evaluation, and recovery of both minerals into salable products or feedstocks to assess the technical and economic potential of the integrated process.”
The laboratory program was the first testing program performed on the two selected composite samples. Testing was performed at laboratory scale using roll-on-bottle tests. Each sample was tested by direct RZOLV filtration as a baseline, and in parallel was subjected to a copper pre-treatment step aimed at extracting a fraction of the copper in a separate liquid prior to RZOLV gold filtration. Each case was generally tested once, with no confirmed recurrences.
After copper pretreatment, the resulting residue was filtered with laboratory-scale RZOLV using bottle-spinning tests with a target particle size of less than 120 microns. Solid samples, including heads and tailings, were sent to ALS for analysis, while process solutions were analyzed internally. The gold recoveries contained in this press release are calculated recoveries specific to the samples tested and laboratory conditions applied. Further confirmation, replication, scale-up and economic testing will be needed before any commercial application can be identified.
The results indicate that the higher gold and lower copper composite responded strongly to direct RZOLV leaching, achieving 94.8% of the calculated gold recovery. After pretreatment, the calculated head gold recovery rate was 89% (subject to final formulation verification), with low RZOLV additions reported. This suggests that for low copper materials, direct filtration of RZOLV may be preferable where recovery is already strong.
The compound with lower gold color and higher copper showed a different response. Direct RZOLV leaching achieved 82.3% calculated gold recovery, while the pretreated route achieved 84.1% and was associated with lower reported RZOLV additions. The company believes this supports further evaluation of copper pretreatment for materials with high copper content; Mechanisms affecting reagent demand require confirmation through additional controlled testing.
No gold was detected in the pretreatment fluids under the analytical method used, indicating that the copper removal step did not measurably dissolve the gold under the conditions tested. This indicates that copper can be extracted while gold is retained in the solid residue for subsequent RZOLV filtration.
In some conventional cyanide-based flow tables, the copper-bearing feed may require additional copper management circuits, such as sulphide, acidification, recycling and thickening (SART), depending on the copper mineralogy, solution chemistry and operating requirements of the project. Such circuits can increase process complexity, capital and operating requirements. The current laboratory results support further evaluation of the proprietary RZOLV platform as a potential alternative integrated approach for sequential copper extraction and gold leaching from selected copper-bearing materials.
The company considers the results positive and encouraging because they were achieved during the first laboratory evaluation of selected samples and before systematic process optimization, and they provide a basis for repeat testing, process optimization and evaluation of the integrated approach to copper and gold recovery. Results are sample specific and do not determine optimal recovery, commercial viability, or expected performance over other materials.
The company notes that the results are preliminary laboratory results and are specific to the samples and conditions that were tested. The results should not be construed as proving commercial viability, mine performance, or economic recovery potential.
Key limitations include: The testing was performed on a laboratory scale using a roll-on bottle test and has not yet been validated at an experimental or commercial scale.
Results are specific to the samples tested and may not be representative of other ore types, deposits, mineralization patterns or operating conditions.
Gold grades in the tested materials were low, and the duration of the gold solution was close to the analytical detection limits. Calculated and calibrated head degrees may vary due to sample heterogeneity. Differences in gold recovery between direct and processed tests should be confirmed by repeat testing.
Additional work is required to improve pretreatment conditions, RZOLV filtration conditions, washing efficiency, copper removal, final recovery, reagent recycling, environmental performance, and overall process economics.
Based on these results, the company intends to consider further testing to evaluate repeatability, optimize copper pretreatment, improve copper removal, evaluate potential copper byproduct recovery, and validate performance through larger batch testing or continuous flow testing.
RZOLV Technologies is developing a proprietary hydrometallurgical chemistry platform for the recovery of precious and critical metals from ores, concentrates, tailings and selected secondary feedstocks.
The company’s flagship technology, RZOLV™, is a proprietary, water-based, non-cyanide dissolution system designed to support metal recovery in applications where traditional cyanide-based methods may be limited by metallurgy, permits, toxicity, environmental management or operating cost. RZOLV™ is being developed as a controlled redox platform intended to provide mining and resource recovery operators with an alternative recovery pathway for selected feed materials.
RZOLV Technologies is deeply saddened to announce the passing of Chester Ferguson Millar, Canadian Mining Hall of Fame member, pioneering mining entrepreneur, beloved father, grandfather, great-grandfather, mentor and friend to many. Chester passed away peacefully surrounded by his family on Tuesday, June 23, 2026, at the age of 98.
