Name of the Project
Mt Thirsty cobalt project.

Location
The project is located 20 km north-north-west of Norseman, in Western Australia.

Client
Mt Thirsty Joint Venture (JV), which comprises Barra Resources (50%) and Conico (50%).

Project Description
A scoping study on the project has returned a robust set of financial metrics over a 21-year mine life.

The Mt Thirsty deposit will be mined by openpit, reaching a maximum depth of about 155 m.

The project is based on a sulphur dioxide (SO₂) leach circuit targeting enriched manganese horizons, with a design capacity of 1.5-million tonnes a year.

Processing will comprise a crushing and grinding circuit followed by an atmospheric, low-temperature, agitate leach circuit using SO₂ gas as the active reagent to selectively leach cobalt and nickel from the enriched manganese horizons; a neutralisation circuit for impurity removal; a six-stage countercurrent decantation circuit to recover pregnant liquor, cobalt and nickel sulphide precipitation, with sodium sulphide and a tailings neutralising stage to raise the pH to 7/8 for disposal to a tailings dam.

The project processing plant has been designed to process up to 1.5-million tonnes of run-of-mine ore a year.

The feed consists of oxide material containing head grades of 0.12% cobalt and 0.52% nickel, as well as significant levels of smectite, silica and goethite. The overall metal recovery to the mixed sulphide product (MSP) with the selected flowsheet was estimated to be 73% for cobalt and 21.5% for nickel, with the plant producing about 6 000 t/y of MSP.

An MSP has been selected to maximise the payable component for cobalt from the mixed cobalt and nickel intermediate product.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The scoping study envisages a preferred base case after-tax net present value, at an 8% discount rate, of A$290-million and an internal rate of return of 21.5%, with a payback of four years.

Value
The project has a low capital cost of A$212-million.

Duration
The MSP is expected to take two years to complete and commission.

Latest Developments
The JV partners plan to examine several alternatives to advance the project, including:
• finding a JV partner to fund further studies, such as prefeasibility studies (PFSes) and feasibility studies, and, subject to the outcome of these studies, develop the project;
• undertaking discussions with cobalt end-users, with the possibility of offtake agreements and/or funding to conduct further studies and potentially develop the project;
• examining alternative sources of finance, such as stream funding, to fund further studies and/or develop the project; and
• progressing a PFS and/or feasibility study under the current JV arrangement or other appropriate corporate structure.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Barra Resources, tel +61 8 9481 3911 or fax +61 8 9481 3283.
Conico, tel +618 9282 5889, fax +618 9282 5866 or email mailroom@conico.com.au.