Name of the Project
Coburn mineral sands project.

Location
Gascoyne region, Western Australia.

Project Owner/s
Mineral sands developer Strandline Resources.

Project Description
An updated definitive feasibility study (DFS) has resulted in significant increases in forecasted financial returns for the project over an initial 22.5-year mine life.

The project has Joint Ore Reserves Committee-compliant ore reserves of 523-million tonnes grading 1.11% total heavy minerals for about 5.8-million tonnes of contained heavy minerals.

The mining study has confirmed a conventional openpit dry mining operation where free-dig unconsolidated sand is mined using heavy mobile equipment to transport material to dozer mining units. The units prepare the ore for processing and the ore is pumped in slurry form to the processing plant.

Bulk metallurgical testwork of representative samples using full-scale or scalable processing equipment has confirmed conventional processing capable of producing high-quality products, with exceptional pit-to-product recovery rates achieved within concentrate and the final product streams.

The DFS has further confirmed an efficient and modern process design capable of producing a high-grade saleable 95% heavy minerals concentrate product from the wet concentration plant, and final products through further processing by the mineral separation plant.

The project will produce four final products comprising a premium zircon product (66% zirconium dioxide), zircon concentrate product (payable zircon, titanium and monazite minerals), rutile product (93% titanium dioxide) and a chloride-grade ilmenite product (62% titanium dioxide).

The updated DFS is still based on a throughput of 23.4-million tonnes a year with an average production of 34 000 t/y of zircon, 54 000 t/y of zircon concentrate, 110 000 t/y of chloride ilmenite and 24 000 t/y of rutile, which are expected to supply about 5% of the global zircon market.

There is potential to further increase project reserves and mine life by about 15 years – to 37.5 years – through the conversion of resources extending north and along strike of the current ore reserves.

Potential Job Creation
Peak workforce during construction is estimated to be more than 300 people, with an average operational workforce during production of about 150 direct skilled workers.

Net Present Value/Internal Rate of Return
The project has a pretax net present value, at an 8% discount rate, of A$705-million, up from A$544-million in the feasibility study. The pretax internal rate of return has increased from 32% to 37%.

The project has a payback of 2.1 years.

Capital Expenditure
Capital expenditure (capex) has increased from A$257-million in the DFS to A$260-million in the updated DFS.

Planned Start/End Date
The project will take 18 months to design and build to achieve first ore to the process plant.

Latest Developments
Strandline Resources’ Coburn mineral sands project has facilitated the start of openpit mine development two months ahead of schedule.

After the successful early mobilisation of the mining contractor in April, Strandline has said that the construction of the temporary tailings storage facility is almost completed, and that prestrip mining will start in July 2022.

Mine development will run concurrently with finalising the construction of the processing and supporting infrastructure, which remains on-budget and on track for first production of heavy minerals concentrate later this year.

Detailed mine planning optimisation by consulting engineering firm AMC Consultants, using the latest infill drilling data, has resulted in an enhanced pit design for the first two years of the mine plan, which contains less overburden and a lower strip ratio, as well as potentially reduced mining costs, compared with assumptions contained within the Coburn DFS.

The strip ratio has reduced from an average of 0.7 to 0.5 over the first two years of the mine plan, owing primarily to optimising and scheduling more ore closer to surface on the eastern side of the deposit.

Moreover, the three dozer mining units have been delivered and assembled on site, ready to be moved into position for mining first ore later this year.

The commissioning of the subsystems associated with the wet concentration plant and hybrid power station are expected to start in July as construction verification works ramp up.

The capital expenditure forecast to complete the project, including an assessment of contractual claims received to date, is being regularly evaluated by the company’s technical, financial and legal experts. The project forecast remains in line with the overall capex budget.

Key Contracts, Suppliers and Consultants
R Engineering Services, AMC Consultants (detailed mine plan), IHC Robbins, AECOM and TZMI’s Allied Mineral Laboratories (DFS); SRK Consulting (technical due diligence of engineering designs and planning associated with geology, hydrology, mining, processing, infrastructure, logistics, implementation strategies, cost estimates, and environmental, social and permitting); Deloitte Access Economics (independent economic cost-benefit analysis); TZ Minerals International (product quality and marketing) and Macmahon (construction of road access and bulk earthworks); Piacentini & Son (in-pit dozer mining units) and Primero (engineering, procurement and construction, and commissioning and performance testing of the wet concentration plant, minerals separation plant and associated processing circuits); and Mine Site Construction Services (mining services contract).

Contact Details for Project Information
Strandline Resources, tel +61 8 9226 3130 or email enquiries@strandline.com.au.