Mr. Shane Williams reports
WEST RED LAKE GOLD ANNOUNCES POSITIVE METALLURGICAL TEST RESULTS FROM ROWAN MINE DEPOSIT
West Red Lake Gold Mines Ltd.
has released positive metallurgical test results from the Rowan mine deposit, which is part of the 100-per-cent-owned Rowan property located in the prolific Red Lake gold district of Northwestern Ontario, Canada.
Highlights of metallurgical test results
The Rowan mine deposit exhibits an excellent response using conventional metallurgical techniques with a very high percentage of gravity recoverable gold (GRG). As expected, the GRG component occurs as coarse gold, which is also seen at Madsen and the satellite deposits: Russet, Fork and Wedge. The metallurgical test work was completed using the Madsen mill flowsheet, with the same specifications and parameters currently in place at the Madsen mill:
Test work completed on the Rowan master composites (MCs) indicates that Rowan vein
material can be processed through the Madsen mill with minor changes to the existing flowsheet.
The results indicate the MCs tested produce very high gravity recovery, with overall gold extraction above 98 per cent after a 48-hour cyanide leach of the gravity tailings.
Gravity recoverable gold (GRG) ranged from 75.8 per cent to 94.9 per cent and the gold was found to be coarse to very coarse.
At a primary grind of 80 per cent passing (P80) 75 microns, very low cyanide consumption, below 0.23 kilogram per tonne (kg/t), was required to achieve gold extractions above 98 per cent.
Shane Williams, president and chief executive officer, stated: "The results of this first phase of metallurgical test work at Rowan have exceeded our expectations, and represent a significant step forward in derisking this high-grade resource. It is very encouraging to see gold recoveries in the order of 98 per cent using the same process flow sheet as the Madsen mill. Furthermore, the high percentage of gold that is able to be extracted via gravity methods only further increases our confidence in the Rowan deposit as a future source of high-grade, easily recoverable gold ounces that could potentially add a significant boost to the overall production profile at Madsen."
Details of metallurgical program
The metallurgical test program was completed by Base Metallurgical Laboratories (BaseMet), a leading metallurgical testing and consulting firm based in Kamloops, B.C. The test work was completed on four MC samples representative of Rowan vein zones 101, 102, 103 and 104 (MC-101, MC-102, MC-103 and MC-104, respectively). The MC samples were created from contiguous intervals of material from 14 NQ-diameter diamond drill holes throughout the Rowan deposit. The metallurgical test program was designed and supervised by Kelly McLeod, PEng (K-Met Consultants Inc.).
The table entitled "Head assays for the four master composites from BaseMet" shows the head grades for the four MCs. Due to the nuggety nature of the gold in the material, MC head grades vary with each test charge -- for example, a range of 4.6 grams per tonne to 15.3 g/t Au was measured during the leach tests.
Discussion of the metallurgical program results
The preliminary test work completed on the Rowan MCs indicates the material can be processed through the Madsen mill with minor changes to the existing flowsheet. The results indicate the MCs tested produced very high gravity recovery with overall gold extraction after a 48-hour cyanide leach of the gravity tailings above 98 per cent. Like Madsen, the leach tests were completed at low cyanide consumptions and successfully achieved the target cyanide weak acid dissociable (CNWAD) in the final tailings of less than one part per million (ppm) using the previously established Madsen conditions for cyanide destruction.
Mineralogy and comminution
Bulk mineralogy analysis (BMA) was completed on all four MC samples. As observed at Madsen and the satellite deposits, the main sulphides present are pyrrhotite followed by pyrite. Sphalerite is also present at Rowan and tends to often be spatially associated with visible gold.
Comminution test work conducted on the MCs yielded the following results:
The Rowan samples tested were harder than the Madsen and satellite deposits.
- The bond ball work index (BWI) for the Rowan MCs ranges from 16.2 kilowatt-hours per tonne to 18.2 kWh/t -- for comparison, Madsen ranges from 9.7 kWh/t to 17.1 kWh/t and averages 14.4 kWh/t.
- The SAG mill comminution (SMC) test results are outlined in the table entitled "SMC test results summary for the Rowan master composites."
Gravity recoverable gold (GRG) test work was completed on MC-101, -102 and -103;
- All three MCs have a significant amount of coarse gravity gold;
- MC-101, MC-102 and MC-103 had a GRG of 93 per cent, 94.9 per cent and 75.8 per cent, respectively;
- The gravity component is coarse to very coarse, as seen in the Madsen and satellite deposits.
The leach tests were completed using the Madsen mill flowsheet;
The gold extraction at 24 hours (residence time in the Madsen leach circuit) was above 95 per cent for all four MCs tested with high gravity recovery -- for comparison, the Madsen mill averaged 95 per cent;
The final extractions at 48 hours were above 98 per cent with cyanide consumption below 0.23 kg/tonne;
High gravity recoveries to the pan concentrate of over 67 per cent were recorded, with the exception of MC-103 which had a recovery of 42.3 per cent. Operational data from the Madsen mill averaged 45 per cent recovery to the pan concentrate;
Due to the coarse nature of the Rowan gold and slightly slower leach kinetics of MC-102, an additional leach tank will be added to the flowsheet;
The Madsen detox circuit is designed for one-hour residence time, 5:1 SO2 (sulphur dioxide):CNWAD and 30 milligrams per litre (mg/L) CuSO4.5H2O (copper sulphate pentahydrate), with a target of less than five ppm CNWAD.
The cyanide destruction test work completed on the MCs indicates the Rowan material can achieve a final tailings CNWAD of less than one ppm Au following the Madsen design parameters and flowsheet.
Additional test work and opportunities
Additional metallurgical test work at Rowan will include prefeasibility study (PFS)-level studies to confirm extraction with varying head grades, as well as running the flowsheet on a number of variability samples from throughout the Rowan deposit.
The Rowan mine target consists of more than seven subparallel, near-vertical, east-west-trending veins that are currently defined over a strike length of approximately 1.1 kilometres -- mineralization remains open along strike and at depth. The orientation of the veins at the Rowan mine tend to follow the direction of D2 deformation, which is oriented in an east-west direction over this part of the property. Individual mineralized vein zones usually average one m to 1.5 m in thickness, with an overall thickness of the Rowan vein corridor at around 115 m. Gold mineralization is typically localized within quartz-carbonate veins hosted within and along the footwall margin of a porphyritic felsic intrusive, with increased grades often associated with the presence of visible gold and base metal sulphides (for example, galena and sphalerite). High-grade dilation zones or ore chutes along the Rowan vein trend have been recognized as important controls for localizing thicker and higher-grade zones of gold mineralization. The position and geometry of these dilation zones is well understood at Rowan.
The drilling completed at the Rowan mine target in 2023 has been focused on validating historical data across the inferred resource, and also infilling apparent gaps in the analytical data set which was a product of very selective sampling techniques implemented during previous drilling campaigns. Assay results received from the 2023 drilling program continue to confirm the company's thesis that quartz veining and gold mineralization continue at depth and along strike, with grades consistent with, or higher, than those outlined in the current inferred mineral resource, which remains open in all directions. For example, the 100 vein zone -- which is the farthest north vein currently modelled within the overall Rowan vein corridor -- was previously interpreted to be a lower-grade portion of the block model. Recent drilling has confirmed that higher grades are present within the 100 vein zone below 150 m elevation, suggesting that gold grades are increasing at depth within this zone, which is a trend that has been observed elsewhere in the Red Lake district. Drilling at the Rowan mine target area will continue with an emphasis on infill and expansion of the existing high-grade mineral resources.
Quality assurance/quality control
Drilling completed at the Rowan property consists of oriented NQ-sized diamond drill core. All drill holes are systematically logged, photographed and sampled by a trained geologist at West Red Lake Gold's Mt. Jamie core processing facility. Minimum allowable sample length is 0.5 m. Maximum allowable sample length is 1.5 m. Standard reference materials and blanks are inserted at a targeted 5-per-cent insertion rate. The drill core is then cut lengthwise utilizing a diamond blade core saw along a line preselected by the geologist. To reduce sampling bias, the same side of drill core is sampled consistently, utilizing the orientation line as reference. For those samples containing visible gold (VG), a trained geologist supervises the cutting/bagging of those samples, and ensures the core saw blade is cleaned with a dressing stone following the VG sample interval. Bagged samples are then sealed with zip ties and transported by West Red Lake Gold personnel directly to SGS Natural Resource's facility in Red Lake, Ont., for assay.
Samples are then prepped by SGS, which consists of drying at 105 degrees and crushing to 75 per cent passing two millimetres (mm). A riffle splitter is then utilized to produce a 500-gram course reject for archive. The remainder of the sample is then pulverized to 85 per cent passing 75 microns, from which 50 g is analyzed by fire assay and an atomic absorption spectroscopy (AAS) finish. Samples returning gold values greater than 10 g/t Au are reanalyzed by fire assay with a gravimetric finish on a 50 g sample. Samples with visible gold are also analyzed via metallic screen analysis (SGS code: GO_FAS50M). For multielement analysis, samples are sent to SGS's facility in Burnaby, B.C., and analyzed via four-acid digest with an atomic emission spectroscopy (ICP-AES) finish for 33-element analysis on 0.25 g sample pulps (SGS code: GE_ICP40Q12). SGS Natural Resources analytical laboratories operates under a quality management system that complies with ISO/IEC 17025.
West Red Lake Gold's Rowan property presently hosts a National Instrument 43-101 inferred mineral resource of 2,790,700 tonnes at an average grade of 9.2 g/t Au containing 827,462 ounces of gold with a cut-off grade of 3.8 g/t Au (NI 43-101 technical report entitled "Technical Report and Resource Estimate on the West Red Lake Project," authored by John Kita, PEng, dated Dec. 13, 2022, and filed Dec. 30, 2022, on SEDAR+). The inferred mineral resource is located in the area of the historic underground Rowan mine site and situated within a 1.8 km strike length portion of the regional-scale Pipestone Bay St Paul deformation zone.
The technical information presented in this news release has been reviewed and approved by Will Robinson, PGeo, vice-president of exploration for West Red Lake Gold and the qualified person for exploration at the West Red Lake project, as defined by NI 43-101 -- Standards of Disclosure for Mineral Projects.
About West Red Lake Gold Mines
West Red Lake Gold Mines is a mineral exploration company that is publicly traded and focused on advancing and developing its flagship Madsen gold mine and the associated 47-square-kilometre, highly prospective land package in the Red Lake district of Ontario. The highly productive Red Lake gold district of Northwest Ontario, Canada, has yielded over 30 million ounces of gold from high-grade zones and hosts some of the world's richest gold deposits. West Red Lake also holds the wholly owned Rowan property in Red Lake, with an expansive property position covering 31 square kilometres, including three past-producing gold mines -- Rowan, Mount Jamie and Red Summit.
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