The Copi deposit is a higher-grade strandline-type, ilmenite-rutile-zircon-leucoxene (titanium, zirconium) placer deposit, located in the Murray Basin in south-western NSW. It is within Exploration Licence EL8312 and extends to the north-west into Exploration Licence EL8385 (Sunshine). Similar deposits nearby are mined by Cristal (Ginkgo, Snapper) and Iluka (Woornack) in Victoria.
The Copi Project strandlines are approximately 25km long, 120m to 220m wide and 5m to 10m thick, with approximately 10 - 20m of sediment cover. The mineral assemblage is ilmenite (21%) and leucoxene (23%) dominant, but also contains high value zircon (12%) and rutile (12%). The deposit is characterised as being coarse grained (p80 – 239µm; D50 – 161µm) with low slimes (2.8%) and minimal oversize (2%).
Pre-feasibility study and feasibility study
We have completed an updated Pre-Feasibility Study (PFS) for the Copi Project during December 2019. We proposed to undertake a final Feasibility Study (FS) during 2020.
In order to undertake the proposed FS, Relentless Resources will be required to complete the following:
Proposed operating philosophy
Our proposed operating philosophy will be based on a dry mining open pit truck and excavator operation processing 1.5 million tonnes per annum (tpa) of heavy Mineral Sands. The wet concentrator plant (WCP) will produce a heavy mineral concentrate of approximately 100,000 tpa for further processing onsite site at the conductor – nonconductor / electrostatic plant (ESP). The ESP products will be transported by road train to the Broken Hill rail terminal for transit to Port Adelaide and shipped to customers internationally.
The proposed operations at Copi will be similar to other dry sands mining operations of a comparable scale and locations. It is expected the mining activities will be conducted by a contractor, with permanent employees used to operate the process plants (concentrator and ESP) and undertake all other operating and management activities.
Proposed mining operation
A contractor operated dry mining open pit mining methodology is proposed as the preferred mining method. This is a commonly adopted mining method used for similar projects using readily available and non-bespoke mining equipment. No drilling and blasting will be required.
The proposed mining method has the following steps:
For those sections of the deposit that are narrow and the advance rate of the mining faces results in an excessive number of MMU moves, the MMU will be located outside the pit and the exposed ore will be mined with trucks and excavators before being placed in the MMU.
Metallurgy and processing
In December 2016 and November 2019, we commissioned Bulk Metallurgical Test Work and Process Concept Development Programs. These programs, which are continuing, involve the processing of a ore samples sourced from the Copi Project strandlines and conducting various testwork recoveries from HMC through to final products, with the product suite (mix and quality) guided by an in-depth understanding of the titanium dioxide and zircon feedstock market requirements.
Nine potential product streams were identified during the test work:
The test work program continues to provide key details on the measured mass and process yields through both the wet concentrator and ESP plant processes. A combination of these test work results and mineral assemblage information has been used to determine the proposed process flowsheet and mineral recoveries for the Copi Project.
The deposit has unique characteristics including the low slimes and low oversize content, except for the relatively complex mineral assemblage including zircon and Fe-Ti containing minerals, which have undergone various degrees of alteration. The focus of the proposed flowsheet was therefore the rejection of a large proportion of the light gangue minerals (quartz) in the wet concentrator circuit, while minimising the losses of the lower density valuable heavy minerals (rutile/ leucoxene /zircon).
The heavy mineral recovery, yield and concentrate grades have been calculated using test work results and recirculating loads to better reflect the recoveries expected in a full-scale operation.
The WCP will recover the valuable heavy minerals (ilmenite, rutile, leucoxene and zircon) and reject most of the non-valuable, lighter gangue minerals in four stages of gravity separation utilising spirals. The HMC product will be washed with potable quality water from the site’s reverse osmosis plant, to reduce chloride contamination from the site’s raw water which would otherwise cause downstream processing issues.
The proposed circuit will be designed to produce a HMC containing heavy minerals and HMC will be stockpiled for trucking off-site to a point of sale. Coarse tailings from the WCP will be returned to the mining void by pumping and cyclone stacking with water from the cyclone overflow recycled directly to the MMU.
Slimes from the slimes thickener will be pumped to slimes drying dams from which they will be reclaimed and returned to the mining void once dry.
The ESP will recover the valuable two heavy mineral product streams – a conductor stream (TiO2 feedstock products – ilmenite, leucoxene and rutile) and a nonconductor stream premium grade zircon product. The ESP circuit will consist of a dump hopper, a dryer, a three-stage electrostatic circuit utilizing, High Tension Roll (HTR) machines, elevators, product bins to store conductors, non- conductor and middling products. The ESP tails will be stockpiled for additional processing or returned to the mining void via the WCP return tailings system.
The below list itemises the typical infrastructure items the project will require to operate efficiently:
Acquisition of these items will be the subject of additional project funding once the Feasibility Study has been completed and regulatory approvals for the Copi Project have been obtained.
Proposed product transport logistics
We propose the HMC product be transported to the final customer, via a newly constructed site access road to the Anabranch Mail Road and then onto the existing Silver City Highway to Broken Hill. Rail freight will be used from Broken Hill to the Port of Adelaide and then ocean freight (in circumstances where the final customer is located overseas). It is expected that HMC loading at site, road freight, rail freight and ship loading will be undertaken by a specialist logistics contractor for the duration of operations.
Permitting and approvals status
The following NSW-based approvals, leases, licences and permits will be required for the proposed project:
In order to obtain these, we were required to complete an Environmental Impact Statement. As a precursor to completing an EIS, the Company is also required to receive a SEARs, which details the matters requiring consideration in the preparation of the EIS.
We have obtained our SEARs and progressing the Environmental Impact Statement process, which will lead to the grant of the environmental protection license. Once that license has been granted, we will be able to obtain its development consent and proceed with obtaining the mining lease and remaining approvals.