Australian copper exploration company Revolver Resources (ASX:RRR) has completed initial engineering design for a site-based copper processing facility at the Dianne Project in North Queensland.
Revolver reports it engaged process plant commissioning engineers and metallurgists company PPM Global to undertake the process engineering and design work as a precursor to a more comprehensive Scoping Study for the Dianne Mine mineral resource.
This design work assumes that the heap leach Solvent Extraction/Electrowinning (SX/EW) facility will be constructed onsite at Dianne and will operate to produce grade A copper cathode. The copper cathode will be trucked to a storage facility at the Port of Cairns before shipping to market.
A full Scoping Study has now started at the historic Dianne Pit based on earlier quantified results obtained from metallurgy and a Mineral Resource Estimate (MRE) from late 2022.
The company says potential to process ore onsite removes the reliance on multiple processing solutions, as well as any reliance on direct shipped ore deliveries, or transport of any concentrate products.
Starting with the metallurgical and resource studies released in late 2022, and now combining the outcomes of this preliminary process design work, Revolver reports it will continue to action more detailed investigations into the near-term production potential at Dianne.
Dedicated scopes of work to be completed include about 800m of infill drilling, laboratory analysis, metallurgical testwork for sulphide leaching as well as follow-up oxide leach testwork, and capital and operating cost estimates for the proposed process plant design.
Revolver notes the development of any open-pit operation at Dianne, as an expansion to the historic open-cut excavation, requires minimal establishment works given that the basic infrastructure and services are already in place.
A full Scoping Study has now started at the historic Dianne Pit based on earlier quantified results…
The company reports incremental permitting steps are in progress and the project is contained entirely within the existing mining lease footprint.
For the process of heap leaching, Revolver says copper-bearing ore will be crushed and stacked on specially prepared and lined pad areas with overall dimensions of about 300m in length, and 240m in width. Heaps will be stacked in the available pad area by truck dumping the material, followed by stacking and levelling with an excavator to about 5m in height.
The process design assumes heap leach activities of oxide and sulphide material in parallel with each pad construction on a bench-by-bench blend of oxide and sulphide. This blended pad construction will allow the progressive inclusion of the ‘higher grade’ sulphide on a more dispersed and regular sequence, alleviating retention times and delayed metal recovery.
Key metallurgical assumptions include copper recovery from supergene oxide ores of 85%, and copper recovery from supergene sulphide ores of 75%.
Moderate copper recovery assumptions for transitional and sulphide ore are based on PPM Global’s experience with similar ore type performance on current heap leach-SX/EW operations such as Girilambone in New South Wales.
Chalcocite leaching is also carried out across several South American heap leach facilities to achieve recoveries of over 80% by employing leaching methods such as forced aeration and salt addition to enhance chalcocite leach kinetics and recovery.
Revolver reports primary sulphide leaching has developed ‘significantly’ over the past 10 to 15 years with both patented leach processes such as BioHeap, as well as in-house developments by companies leaching predominantly primary sulphide ore.
Operations such as Wetar in Indonesia have leached to ‘high’ recoveries, a predominantly primary sulphide ore by in-house development of specific leaching methodologies such as aeration and solution flow rate control to manage temperature within the heap.
The company reports further studies and subsequent testwork will inform the process design and requirement for aeration and/or leach chemistry adjustments to suit the mineralogy of the Dianne deposit.
Revolver estimates the processing plant can be established within 10 months from the project execution date, after receiving all required statutory approvals.
Revolver Resources is an Australian copper exploration company focused on developing natural resources for the world’s accelerating electrification. The company’s near-term focus is the development of its Dianne and Osprey projects in Northwest Queensland.
Images: Revolver Resources Holdings Ltd
