Name and Location
Cleveland tailings project, Tasmania.

Client
Elementos.

Project Description
A prefeasibility study (PFS) completed on the Cleveland tailings project has shown the project to be technically and financially viable, with a risk profile that is competitive or better than other global assets at a similar stage of development.

Several mining methods have been reviewed in the PFS and a loader-to-truck method was selected.
A total of 3.7-million tonnes of the tailings with an average head grade of 0.29% tin and 0.13% copper will be mined at the rate of 650 000 t/y.

Mining will be executed in four phases.

Phase 1 will involve re-establishing the site, making it ready for construction of mining and reprocessing infrastructure, as well as establishing water management.
Phase 2 construction will include:
• construction of a starter embankment of the new tailings storage facility;
• refurbishment of the process water dam and construction of a polishing pond;
• construction and commissioning of the process plant and administration/ablution building; and
• clear and grub of Tailings Dam 1 (TD1), with Tailings Dam 2 being prepared at the end of mining TD1.

In Phase 3, an active mine face will be established at the beachhead of TD1, the closest point to the proposed plant location. The clay cap and float will be removed by truck and stockpiled for reuse. Any removed vegetation will be stockpiled for use in rehabilitation.

An active mining area will be exposed, containing feed for a minimum of three shifts.

Limiting the removal of the clay cap reduces the amount of surface water that can enter the dams and will also reduce dust. All material removed from the tailings dams will be periodically sampled for acid mine drainage (AMD) characterisation.

The float material is predominantly chert – a benign, high-silicate rock. Subject to AMD testing, the float will be reused on site for road sheeting.

The stockpiled clay and any remaining float will be used in the construction of later lifts of the tailings storage facility.

The tailings (ore) material will be mined in a single bench. Sumps will be dug into the work area floor to dewater the floor and the remnant water trapped in the tailings dams.

All water collected will be pumped to the process water dam and recycled to the process plant.

The tailings dam wall will be exposed so that surface water runoff is controlled and scouring of the underlying sediments is prevented.

Phase 4 will involve the rehabilitation of the processing and office areas, historical tailings dams, roads and some water management structures.

The process plant will use conventional gravity and flotation technologies. Owing to the deposit type, no primary comminution (crushing or grinding) will be required before beneficiation.

Concentrate dressing will include an acid leach process.

The plant will produce two saleable concentrate products – a tin concentrate grading 51% tin and a copper concentrate grading 18% copper, with recoveries of 47% and 31% respectively.

Net Present Value/Internal Rate of Return
The project has a pretax net present value, at an 8% discount rate, of A$34-million and a pretax internal rate of return of 68%, with a payback of three years.

Value
The total capital requirement, including contingency, is A$30.6-million.

Duration
Production is scheduled to start in the 2016/17 financial year.

Latest Developments
The PFS recommends that the project advance to the next stage of development, which will involve a feasibility study (FS) and continuation of the approvals process.

The FS is scheduled for completion in the third quarter of 2016 and, subject to obtaining all the necessary approvals, production is scheduled to
start in late 2016.

Key Contracts and Suppliers
Not stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Elementos, tel +61 7 3321 7770, fax +61 7 3221 7773 or email admin@elementos.com.au.