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Caravel Minerals Limited (ASX:CVV) is pleased to announce The Caravel Copper Project Pre-Feasibility Study (PFS) Update – Single Train Option Study (see ASX Announcement 20 September 2022) outlined the adoption of a single train design using High Pressure Grinding Rolls (HPGRs) in the processing plant’s primary grinding circuit, replacing Semi-Autogenous Grinding (SAG) mills originally selected in the PFS released on 12 July 2022. Further testwork has now been completed, better defining the assumptions used for the HPGR performance and specifications.
HIGHLIGHTS
- High Pressure Grinding Roll (HPGR) tests confirm Pre-feasibility Study design assumptions, including required crusher performance, reduced energy usage and higher throughput rates
- Results confirm commercial scale assumptions supporting a 27Mtpa Project with potential for future upside capacity
- Further studies will explore operating strategies to optimise power consumption and pricing
A two (2) tonne bulk sample from the Bindi East and Hinge Zone starter pits was sent for HPGR testing at the Bureau Veritas Mineral Laboratory in Perth, Western Australia. The work was conducted using an Enduron® test unit with a roll diameter of 0.80m and 0.25m wide. A total of six (6) tests were performed to determine grinding performance, energy use, wear rates, and design parameters for commercial scale application.
The tests achieved the expected size reduction from ~30mm to ~8mm, under an operating pressure of 3N/mm2 while consuming 1.6 kWh/t and operating at a nominal throughput rate of 265t/hr-m3. The positive results confirm the PFS assumptions which are typical for copper ores and confirm HPGR’s can achieve Caravel’s processing plant throughput of 27mtpa..
Two HPGRs will be incorporated into the overall crushing and grinding circuit, consisting of a primary gyratory crusher, secondary cone crushers, HPGRs and ball mills. The project is evaluating the merits of selecting industry proven HPGRs sized at 2.4m diameter, each with 8MW drives.
Additional tests are underway to optimise the energy usage across the HPGR crushing ball mill grinding circuit. Power management is an increasingly important opportunity for grid connected facilities that seek to maximise their utilisation of renewable energy and reduce exposure to short duration price peaks.
This announcement is authorised for release by Managing Director Don Hyma.
About High Pressure Grinding Rolls (HPGR’s)
HPGR units originated from the cement sector and were introduced in the mid-1980s for use in the diamond and iron ore sectors. They are now widely used in the general metalliferous industry. The copper and gold sector has increasingly used HPGRs to process harder and more abrasive ores. With more applications of the technology and ongoing development, operability and reliability has improved with industry benchmarks demonstrating operating availability of more than 90%.
Unlike conventional roll crushing, HPGR achieves a size reduction through inter-particle compression rather than crushing of particles between the roll surfaces. Abrasion on the roll surface is managed by replaceable studs composed of highly abrasion resistant alloys. These studs are the only consumables for operation of the HPGR and can be rapidly replaced when necessary. This results in minimal downtime for maintenance and allows HPGR’s to operate with very high reliability.
Image illustrating direction of material movement through a HPGR
Image of an abrasion resistant HPGR studded roll
HPGR test unit at Bureau Veritas Minerals Laboratory, Perth, Australia
Caravel ore crushed using Enduron® test unit
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This article includes content from Caravel Minerals Limited, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
High grade Assay Results Continue at Youanmi
- The latest batch of assays have been received from the 11,000m drilling program (both diamond core and reverse circulation) at the high gold-grade Youanmi Gold Project, located centrally in Western Australia’s prolific gold fields
- The recently-completed infill/exploration program aimed to improve resource confidence and open up corridors for resource growth; to underpin the Definitive Feasibility Study (DFS), and, additionally, provide sample material for ongoing metallurgical optimisation test-work for the DFS program
- Latest highlights from the program include:
- RXDD131: 4.38m @ 19.07 g/t Au from 387.98m,
- incl. 1.73m @ 41.43 g/t Au from 389.96m
- RXDD119: 4.56m @ 14.60 g/t Au from 220.64m
- RXDD115: 2.99m @ 21.11 g/t Au from 249.88m
- RXDD119: 4.0m @ 7.37 g/t Au from 162.0m
- RXDD132: 7.19m @ 3.90 g/t Au from 263.61m
- RXDD133: 2.83m @ 6.53 g/t Au from 431.00m
- RXDD128: 3.82m @ 4.51 g/t Au from 364.59m,
- incl. 1.73m @ 8.22 g/t Au from 364.59m
- incl. 1.73m @ 8.22 g/t Au from 364.59m
- RXDD122: 0.95m @ 13.50 g/t Au from 204.44m
- §These results further demonstrate the continuity of high- grade gold mineralisation along the Youanmi greenstone belt belt, and the potential for resource growth both at depth and along-strike, with discovery potential to the south
- 35,000m Step-up drill campaign well underway with the plan to bring forward ounces and increase the mine plan
The program focused on converting Inferred stopes at Pollard, United North and Youanmi Main to higher confidence Indicated classification and providing material for metallurgical testing for the upcoming Definitive Feasibility Study (DFS) – on track for H2 CY25.
This final consignment of diamond assay results are the fourth batch of assays results returned from the drill program and have been entirely drilled from the Pollard, Youanmi and United North areas (Figure 1).
Rox Resources’ Chief Executive Officer, Phillip Wilding, commented:
“It’s pleasing to round out the 11,000m RD and DD drilling program with another batch of excellent intercepts.
“More importantly, the program has significantly improved our knowledge of the high grade and underexplored Youanmi ore system, and shown that mineralisation remains open at depth.
“Next steps are to convert Inferred areas of the Resource to the higher confidence Indicated classification, and finalise key intercepts of sample material for metallurgical test work to feed into the Youanmi DFS.
“We are excited to have commenced the 35,000m Step-up program to potentially bring forward ounces in the mine plan and significantly increase the size of the Pollard ore zone.”
Youanmi Major Growth Drill program
Resource drilling has focused on converting selected Inferred stopes in the current Mineral Resource of 16.2Mt at 4.4g/t Au for 2.3Moz (Indicated: 10.7Mt at 4.5g/t Au for 1.6 Moz : Inferred 5.5Mt at 4.2g/t Au for 0.7 Moz) 1 to higher confidence Indicated classification at Pollard, United North and Youanmi Main as shown in plan on Figure 1. The drilling has also provided both sample material for metallurgical testing and valuable geological data for the pending Definitive Feasibility Study (“DFS”) planned for second half of 2025.
Figure 1: Plan view of the Youanmi Gold Project featuring drill hole collar locations and 2024 Resource outline overprinted on aerial photography
Outside of the immediate resource area, drilling was also conducted on near-mine exploration and focused on the Youanmi South prospect area, or Paddy’s Lode, first reporting high-grade intercepts in 20232. The drilling at Paddy’s has complimented the Company’s exploration strategy moving south along the Main Lode Shear Zone (MLSZ) and adding additional gold ounces to the Resource. Youanmi South has the potential to grow the Resource above the 103kozpa Production Target outlined in the recently completed Pre-Feasibility Study (“PFS”)3.
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This article includes content from Rox Resources Limited, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
Drilling Commenced at Viani in Fiji
HIGHLIGHTS
- The Phase 1, three-hole diamond drilling program has commenced at the Viani Project, Fiji and will test for extensions to the quartz vein gold mineralisation at depth.
- Phase 1 is expected to be completed in early 2025, with plans for additional drilling under the same program dependent on the initial results
- The Viani Project (SPL1513) covers an area of approximately 200km2 and is largely underexplored.
- At the Dakuniba prospect within Viani, low sulphidation epithermal high-grade gold mineralisation has been mapped over >3km strike length.
- Diamond drilling completed by Japan International Cooperation Agency (JICA) in 1995 to 1997 intersected high-grade gold in low sulphidation epithermal quartz veins, including 0.6m @ 27.6 g/t Au.
Alice Queen’s Managing Director, Andrew Buxton said,
With drilling underway, Alice Queen is positioned to test the epithermal gold-style mineralisation identified in historic drilling at the Viani Project. Weather permitting, we anticipate completing the Phase 1, three-hole diamond drilling program in early 2025. Following this, our exploration team will mobilise the drill rig to the Sabeto Project in Fiji to maintain the momentum of this campaign. To deliver timely results to shareholders, we intend to accelerate the analysis of the drill core at ALS Brisbane.”
Image 1 – Diamond drilling at Viani
Details
Geology
The geology of the Viani Project (SPL 1513) comprises olivine basalts and volcaniclastics of the Natewa Volcanic Group which are intruded by andesite sills and dykes. In the 1940s, gold mineralisation was found by local prospectors near the village of Dakuniba. At Dakuniba, low sulphidation style epithermal gold occurs in quartz veins, and silicified rocks along a 3km long NE trending zone.
In 1995-1997, Japan International Cooperation Agency (JICA) drilled six diamond holes at Dakuniba and intersected high-grade gold in chalcedonic, crustiform, colloform banded quartz veins at depths of 50m to 100m below surface (i.e. MJVFV-5 intersected 2.2m @ 11.3 g/t Au, incl 0.6m @ 27.6 g/t Au at 121m downhole). This high-grade gold mineralisation is open in all directions.
Proposed Drill program
The initial Phase 1 drill program at Viani (see Table 1) will comprise three diamond drillholes designed to test continuity to the epithermal gold mineralisation previously intersected in JICA drillhole MJVFV- 5 (2.2m @ 11.3 g/t Au) (see Figure 2). The drilling will test for extensions to the gold mineralisation at depth and along strike.
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This article includes content from Alice Queen Limited, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
