TORONTO, Sept. 27, 2022 (GLOBE NEWSWIRE) -- Inventus Mining Corp. (TSX VENTURE: IVS) (“Inventus” or the “Company”) is pleased to announce the results from its bulk sampling program at its 100%-owned Pardo Project near Sudbury, Ontario. The 5,000-tonne bulk sample from the 007 Zone returned an average head grade of 3.4 g/t gold (Au) with excellent gravity recoverable gold. The bulk sampling program was successful in reconciling the gold mineralization in the predictive block model that was generated using large diameter infill diamond drill holes.
Key results include:
- A total of 4,979 dry tonnes of mineralized rock was processed with a head grade of 3.4 g/t Au.
- Bulk sample head grade reconciled strongly with the predictive block model grade of 3.3 g/t Au.
- Gravity and flotation concentrate contained 438 oz Au, worth approximately Cad$1,000,000.
- Of the 438 oz Au recovered, 299 oz Au representing 68% was contained in the gravity concentrate, and 138 oz Au representing 32% was contained in the flotation concentrate.
- The overall metallurgical performance of the bulk sample did not balance, which is attributed to high gravity recoverable gold, and approximately 76 oz Au is estimated to remain in the mill circuit.
Geology and Mineralization
The 007 Zone bulk sample was extracted from a horizontal mineralized conglomerate “reef” that occurred from surface to a depth of 4 metres (m). The conglomerate reef was on average 2.5 m thick and consisted of 72% clasts and 28% matrix all the mineralization is contained in the matrix. The mineralization occurs as disseminated pyrite and gold within the matrix that surrounds the clasts within the conglomerate. The conglomerate reef had a sharp footwall contact that is easily identified during mining.
Infill Drilling and Block Model Prediction
Prior to extraction of the bulk sample, the area was diamond drilled with 28 large diameter (7 cm) holes at 5-m centers for grade estimation purposes. Samples of the drill core used in the predictive block model were subject to density measurements (2.79 t/m3) and whole-core sampling to provide an adequate sample size for assay. Geological contacts from the infill drilling were used to create hard boundaries for wireframing the block model domain. The predicted block model had 5,526 tonnes grading 3.3 g/t Au.
Mining and Grade Control
Bulk sample extraction was relatively simple due to the location on surface and horizontal orientation. The bulk sample was drilled and blasted at 1.2-metre centers, and mineralized material was crushed on site to under 4-inches. Due to winter weather conditions during mining, tight controls on blast contacts and pit mucking were not consistently maintained. Post-operation assessment of the bulk sample pit has indicated approximately 450 tonnes of material was left in the pit and over-blasting of the footwall resulted in some dilution.
The mined block mined was from surface to the lower lithological contact of the mineralized reef. Drilling results showed that the upper portion of the reef (surface to 1-1.5 m depth) was the highest grade, while the portion closest to the footwall contact was much lower grade. The decision to extract the whole unit provided important information; however, a more selective mining approach targeting grade could be used.
A total of 5,140 wet tonnes was trucked to the mill near in Timmins between January and February 2022, as measured by the mill truck scale. Processing of the bulk sample occurred in mid-February and produced gravity and flotation concentrates. The results of the bulk sample are presented in Table 1. During the bulk sample run, a total of 89 ball mill feed samples and 88 tails samples were collected to produce nine daily composite samples for assay. The composite samples from the ball mill feed returned an average grade of 3.38 g/t Au (the “head grade”) and samples of the tails returned an average grade of 0.17 g/t Au (the “tails grade”).
The sample was calculated to contain 541 oz Au and a total of 438 oz Au was recovered, representing an apparent reconciled head grade of 2.9 g/t Au and a metallurgical recovery of 81%. However, due to the high percentage of gold recovered by gravity and the large discrepancy between the contained and recovered gold ounces, it is assumed that significant gold remained in the milling circuit. An effort was made to clean out the mill circuit resulting in recovery of 13.7 oz Au, but many areas were not cleaned, including the two ball mills. The amount of gold remaining in the mill circuit is estimated to be approximately 76 oz but cannot be measured. Therefore, the overall true reconciled head grade and recovery of the bulk sample is inconclusive.
Table 1. 007 Zone Bulk Sample Results
1The estimated Au remaining in-circuit is the assumed amount of gold that was not recovered in the milling circuit. We believe that an in-circuit loss is very likely with high gravity recoverable gold and should be considered during future bulk sampling.
The gravity concentrates and high-grade mill cleanup material totalled 8.3 dry tonnes of material with an average grade of 1,118.4 g/t Au. The gravity concentrate was shipped to a smelter in Chicago where analysis showed 299.3 oz Au was contained. The flotation concentrate totalled 102.4 dry tonnes of material with an average grade of 42.0 g/t Au. The flotation concentrate was shipped to a smelter in Quebec where analysis showed 138.3 oz Au was contained.
For further information, please contact:
Mr. Stefan Spears
Chairman and CEO
Inventus Mining Corp.
Tel: (647) 258-0395 x280
About Inventus Mining Corp.
Inventus is a mineral exploration and development company focused on the world-class mining district of Sudbury, Ontario. Our principal assets are a 100% interest in the Pardo Paleoplacer Gold Project and the Sudbury 2.0 Project located northeast of Sudbury. Pardo is the first important paleoplacer gold discovery found in North America. Inventus has approximately 140.6 million common shares outstanding.
Neither 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.
The Qualified Person responsible for the geological technical content of this news release is Inventus’ Vice-President Exploration, Wesley Whymark, P.Geo., who has reviewed and approved the technical disclosure in this news release on behalf of the Company.
The samples used to determine head grade and tails grade assays described in this release were collected by Northern Sun Mining (“NSM”) on behalf of Inventus. The samples were taken by NSM every 2 hours during the run to create a daily composite. The samples collected for the head grade were approximately 1 kg and taken systematically from the belt feeding the ball mill. Samples for the tails grade were collected in a 1 L bottle from the final flotation cell prior to the final tails pump box. The daily composites were dried and split into 150-g subsamples and transported in secure sealed bags for assay by SGS Laboratories.
The samples used to determine gravity concentrate assays described in this release were collected by NSM and Sipi Metals. NSM collected the sample using a pipe sampling unit, collecting 8 pipe samples, weighing approximately 5 kg for each of the 8 bulk bags of gravity concentrate. The samples were then dried and split into 150-g subsamples and transported in secure sealed bags for party assay by SGS Laboratories. The gravity concentrate samples collected by Sipi Metals were made into 5 lots and dried and milled to -40 mesh. Each of the lots was then blended and spear sampled to collect a ~5 kg subsample. The subsample was then further reduced by riffle splitting a 1-kg subsample. The 1-kg subsample was then crushed to -80 mesh and split into three parts. One part of the subsample splits was shipped to Inventus in a secured sealed bag, that in turn, was then delivered to SGS Laboratories by Inventus for assay.
The samples used to determine flotation concentrate assays described in this release were collected the Horne Smelter and assayed by a third-party independent lab, Alfred H Knight.
This News Release includes certain "forward-looking statements" which are not comprised of historical facts. Forward-looking statements include estimates and statements that describe the Company’s future plans, objectives or goals, including words to the effect that the Company or management expects a stated condition or result to occur. Forward-looking statements may be identified by such terms as “believes”, “anticipates”, “expects”, “estimates”, “may”, “could”, “would”, “if”, “yet”, “potential”, “undetermined”, “objective”, or “plan”. Since forward-looking statements are based on assumptions and address future events and conditions, by their very nature they involve inherent risks and uncertainties. Although these statements are based on information currently available to the Company, the Company provides no assurance that actual results will meet management’s expectations.