Name of the Project
Mackay sulphate of potash (SoP) project.

Location
The project is located 785 km south of the Port of Wyndham, in Western Australia.

Client
Agrimin Limited.

Project Description
A prefeasibility study (PFS) has demonstrated the potential for the Mackay SoP project to become a long-life and low-cost supplier of SoP.

The mine plan predicts an average yearly brine extraction rate of 66.3-million cubic metres, with an average SoP grade of 8 kg/m3 over an initial 20-year period. 

This equates to the extraction of 531 000 t/y of SoP and is based entirely on the extraction of the indicated mineral resource (specific yield and total porosity) within the modelled depth of extraction of 3 m below ground.

The production of SoP will begin with the extraction of potassium-rich brine using an on-lake trench system. 

The PFS trench network and feed channel is planned to have a length of 546 km and an average depth of 4.5 m, resulting in 8.50-million cubic metres of excavated material. 

The depth of the trenches will vary to allow for sufficient volume and gradient so that the brine can flow naturally along the trench network southwards to the feed channel. Brine will be transferred along the channel to the solar evaporation ponds using two pumpstations.

The process plant has been designed for a capacity of 426 000 t/y of SoP as dry granular product, with the PFS assuming a product mix of 50% granular and 50% standard product. The PFS assumes all production is exported through the Port of Wyndham through an integrated mine-to-ship logistics chain.

The mine is expected to have an initial operating life of 20 years. Potential exists to increase production rates and/or extend the operational life of the project.

Potential Job Creation
The project will create about 300 jobs during construction and 200 jobs during operations, and is expected to support more than 600 jobs through the broader region and supply chain.

Net Present Value/Internal Rate of Return
The project has a post-tax net present value, at an 8% discount rate, of $453.2-million, and an internal rate of return of 20%, with a post-tax payback of 4.2 years.

Value
Capital costs, including $53-million in contingency, have been estimated at $409-million.

Duration
The project’s construction and commissioning is expected to take 36 months. A production ramp-up of 70% of production is expected in the first 12 months of operations before reaching the full production target of 426 000 t/y.

Latest Developments
The Australian government has granted Agrimin 'major project' status for its Mackay potash project.

This status provides companies with extra support from the Major Projects Facilitation Agency, including a single entry point for commonwealth government approvals, project support and coordination, and help with state and territory approvals

Key Contracts and Suppliers
Advisian (lead engineer and study manager for the PFS); Hydrominex Geoscience and H&S Consultants (mineral resource); Knight Piésold (hydrogeological studies and civil and geotechnical work); Global Potash Solutions (process design); Saskatchewan Research Council (evaporation and process testwork); Qube Bulk (product logistics) and 360 Environmental and Strategen Environmental (environmental work).

Contact Details for Project Information
Agrimin Limited, tel +61 8 9389 5363 or email admin@agrimin.com.au.